Author name code: tarbell
ADS astronomy entries on 2022-09-14
author:"Tarbell, T." 
------------------------------------------------------------------------  

Title: Achievements of Hinode in the first eleven years
Authors: Hinode Review Team; Al-Janabi, Khalid; Antolin, Patrick;
   Baker, Deborah; Bellot Rubio, Luis R.; Bradley, Louisa; Brooks,
   David H.; Centeno, Rebecca; Culhane, J. Leonard; Del Zanna, Giulio;
   Doschek, George A.; Fletcher, Lyndsay; Hara, Hirohisa; Harra,
   Louise K.; Hillier, Andrew S.; Imada, Shinsuke; Klimchuk, James A.;
   Mariska, John T.; Pereira, Tiago M. D.; Reeves, Katharine K.; Sakao,
   Taro; Sakurai, Takashi; Shimizu, Toshifumi; Shimojo, Masumi; Shiota,
   Daikou; Solanki, Sami K.; Sterling, Alphonse C.; Su, Yingna; Suematsu,
   Yoshinori; Tarbell, Theodore D.; Tiwari, Sanjiv K.; Toriumi, Shin;
   Ugarte-Urra, Ignacio; Warren, Harry P.; Watanabe, Tetsuya; Young,
   Peter R.
Bibcode: 2019PASJ...71R...1H
Altcode:
  Hinode is Japan's third solar mission following Hinotori (1981-1982)
  and Yohkoh (1991-2001): it was launched on 2006 September 22 and is in
  operation currently. Hinode carries three instruments: the Solar Optical
  Telescope, the X-Ray Telescope, and the EUV Imaging Spectrometer. These
  instruments were built under international collaboration with the
  National Aeronautics and Space Administration and the UK Science and
  Technology Facilities Council, and its operation has been contributed
  to by the European Space Agency and the Norwegian Space Center. After
  describing the satellite operations and giving a performance evaluation
  of the three instruments, reviews are presented on major scientific
  discoveries by Hinode in the first eleven years (one solar cycle long)
  of its operation. This review article concludes with future prospects
  for solar physics research based on the achievements of Hinode.

Title: The Solar-C_EUVST mission
Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko;
   Ichimoto, Kiyoshi; Suematsu, Yoshinori; Hara, Hirohisa; Katsukawa,
   Yukio; Kubo, Masahito; Toriumi, Shin; Watanabe, Tetsuya; Yokoyama,
   Takaaki; Korendyke, Clarence M.; Warren, Harry P.; Tarbell, Ted; De
   Pontieu, Bart; Teriaca, Luca; Schühle, Udo H.; Solanki, Sami; Harra,
   Louise K.; Matthews, Sarah; Fludra, A.; Auchère, F.; Andretta, V.;
   Naletto, G.; Zhukov, A.
Bibcode: 2019SPIE11118E..07S
Altcode:
  Solar-C EUVST (EUV High-Throughput Spectroscopic Telescope) is a
  solar physics mission concept that was selected as a candidate for
  JAXA competitive M-class missions in July 2018. The onboard science
  instrument, EUVST, is an EUV spectrometer with slit-jaw imaging
  system that will simultaneously observe the solar atmosphere from the
  photosphere/chromosphere up to the corona with seamless temperature
  coverage, high spatial resolution, and high throughput for the first
  time. The mission is designed to provide a conclusive answer to the
  most fundamental questions in solar physics: how fundamental processes
  lead to the formation of the solar atmosphere and the solar wind, and
  how the solar atmosphere becomes unstable, releasing the energy that
  drives solar flares and eruptions. The entire instrument structure
  and the primary mirror assembly with scanning and tip-tilt fine
  pointing capability for the EUVST are being developed in Japan, with
  spectrograph and slit-jaw imaging hardware and science contributions
  from US and European countries. The mission will be launched and
  installed in a sun-synchronous polar orbit by a JAXA Epsilon vehicle in
  2025. ISAS/JAXA coordinates the conceptual study activities during the
  current mission definition phase in collaboration with NAOJ and other
  universities. The team is currently working towards the JAXA final
  down-selection expected at the end of 2019, with strong support from
  US and European colleagues. The paper provides an overall description
  of the mission concept, key technologies, and the latest status.

Title: Multi-component Decomposition of Astronomical Spectra by
    Compressed Sensing
Authors: Cheung, Mark C. M.; De Pontieu, Bart; Martínez-Sykora,
   Juan; Testa, Paola; Winebarger, Amy R.; Daw, Adrian; Hansteen, Viggo;
   Antolin, Patrick; Tarbell, Theodore D.; Wuelser, Jean-Pierre; Young,
   Peter; MUSE Team
Bibcode: 2019ApJ...882...13C
Altcode: 2019arXiv190203890C
  The signal measured by an astronomical spectrometer may be due to
  radiation from a multi-component mixture of plasmas with a range of
  physical properties (e.g., temperature, Doppler velocity). Confusion
  between multiple components may be exacerbated if the spectrometer
  sensor is illuminated by overlapping spectra dispersed from different
  slits, with each slit being exposed to radiation from a different
  portion of an extended astrophysical object. We use a compressed sensing
  method to robustly retrieve the different components. This method can
  be adopted for a variety of spectrometer configurations, including
  single-slit, multi-slit (e.g., the proposed MUlti-slit Solar Explorer
  mission), and slot spectrometers (which produce overlappograms).

Title: Multi-component Decomposition of Astronomical Spectra by
    Compressed Sensing
Authors: Cheung, Mark; De Pontieu, Bart; Martinez-Sykora, Juan; Testa,
   Paola; Winebarger, Amy R.; Daw, Adrian N.; Hansteen, Viggo; Antolin,
   Patrick; Tarbell, Theodore D.; Wuelser, Jean-Pierre; Young, Peter R.
Bibcode: 2019AAS...23411603C
Altcode:
  The signal measured by an astronomical spectrometer may be due to
  radiation from a multi-component mixture of plasmas with a range of
  physical properties (e.g. temperature, Doppler velocity). Confusion
  between multiple components may be exacerbated if the spectrometer
  sensor is illuminated by overlapping spectra dispersed from different
  slits, with each slit being exposed to radiation from a different
  portion of an extended astrophysical object. We use a compressed sensing
  method to robustly retrieve the different components. This method can
  be adopted for a variety of spectrometer configurations, including
  single-slit, multi-slit (e.g., the proposed MUlti-slit Solar Explorer
  mission; MUSE) and slot spectrometers (which produce overlappograms).

Title: Evidence of Twisting and Mixed-polarity Solar Photospheric
Magnetic Field in Large Penumbral Jets: IRIS and Hinode Observations
Authors: Tiwari, Sanjiv K.; Moore, Ronald L.; De Pontieu, Bart;
   Tarbell, Theodore D.; Panesar, Navdeep K.; Winebarger, Amy R.;
   Sterling, Alphonse C.
Bibcode: 2018ApJ...869..147T
Altcode: 2018arXiv181109554T
  A recent study using Hinode (Solar Optical Telescope/Filtergraph
  [SOT/FG]) data of a sunspot revealed some unusually large penumbral
  jets that often repeatedly occurred at the same locations in the
  penumbra, namely, at the tail of a penumbral filament or where the
  tails of multiple penumbral filaments converged. These locations had
  obvious photospheric mixed-polarity magnetic flux in Na I 5896 Stokes-V
  images obtained with SOT/FG. Several other recent investigations have
  found that extreme-ultraviolet (EUV)/X-ray coronal jets in quiet-Sun
  regions (QRs), in coronal holes (CHs), and near active regions (ARs)
  have obvious mixed-polarity fluxes at their base, and that magnetic
  flux cancellation prepares and triggers a minifilament flux-rope
  eruption that drives the jet. Typical QR, CH, and AR coronal jets are
  up to 100 times bigger than large penumbral jets, and in EUV/X-ray
  images they show a clear twisting motion in their spires. Here,
  using Interface Region Imaging Spectrograph (IRIS) Mg II k λ2796 SJ
  images and spectra in the penumbrae of two sunspots, we characterize
  large penumbral jets. We find redshift and blueshift next to each
  other across several large penumbral jets, and we interpret these as
  untwisting of the magnetic field in the jet spire. Using Hinode/SOT
  (FG and SP) data, we also find mixed-polarity magnetic flux at the
  base of these jets. Because large penumbral jets have a mixed-polarity
  field at their base and have a twisting motion in their spires, they
  might be driven the same way as QR, CH, and AR coronal jets.

Title: Instrument Calibration of the Interface Region Imaging
    Spectrograph (IRIS) Mission
Authors: Wülser, J. -P.; Jaeggli, S.; De Pontieu, B.; Tarbell,
   T.; Boerner, P.; Freeland, S.; Liu, W.; Timmons, R.; Brannon, S.;
   Kankelborg, C.; Madsen, C.; McKillop, S.; Prchlik, J.; Saar, S.;
   Schanche, N.; Testa, P.; Bryans, P.; Wiesmann, M.
Bibcode: 2018SoPh..293..149W
Altcode:
  The Interface Region Imaging Spectrograph (IRIS) is a NASA small
  explorer mission that provides high-resolution spectra and images of
  the Sun in the 133 - 141 nm and 278 - 283 nm wavelength bands. The
  IRIS data are archived in calibrated form and made available to the
  public within seven days of observing. The calibrations applied to
  the data include dark correction, scattered light and background
  correction, flat fielding, geometric distortion correction, and
  wavelength calibration. In addition, the IRIS team has calibrated the
  IRIS absolute throughput as a function of wavelength and has been
  tracking throughput changes over the course of the mission. As a
  resource for the IRIS data user, this article describes the details
  of these calibrations as they have evolved over the first few years
  of the mission. References to online documentation provide access to
  additional information and future updates.

Title: Motions in Prominence Barbs Observed on the Solar Limb
Authors: Kucera, T. A.; Ofman, L.; Tarbell, T. D.
Bibcode: 2018ApJ...859..121K
Altcode:
  We analyze and discuss an example of prominence barbs observed on the
  limb on 2016 January 7 by the Hinode/Solar Optical Telescope in Ca
  II and Hα, the Interface Region Imaging Spectrograph, with slit jaw
  images and Mg II spectral data, and the Solar Dynamics Observatory’s
  Atmospheric Imaging Assembly. In the recent literature there has
  been a debate concerning whether these features, sometimes referred
  to as “tornadoes,” are rotating. Our data analysis provides no
  evidence for systematic rotation in the barbs. We do find line-of-sight
  motions in the barbs that vary with location and time. We also discuss
  observations of features moving along the barbs. These moving features
  are elongated parallel to the solar limb and tend to come in clusters
  of features moving along the same or similar paths in the plane of
  the sky during a period of 10 minutes to an hour, moving toward or
  away from the limb. The motion may have a component along the line
  of sight as well. The spectral data indicate that the features are
  Doppler shifted. We discuss possible explanations for these features.

Title: An Innovative Approach to a High Resolution Coronal Imager
(T-07): MUSE, the Multi-Slit Solar Explorer
Authors: Tarbell, Theodore D.; De Pontieu, Bart
Bibcode: 2018tess.conf41004T
Altcode:
  The Next Generation Solar Physics Mission Science Objectives Team
  recommended three instruments flying in space simultaneously: a
  spectrometer with wide temperature coverage (T-09), a high resolution
  coronal imager (T-07), and a photospheric and chromospheric magnetograph
  and spectrograph (T-01,4,5). The coronal imager was inspired by the
  Hi-C rocket payload, whose successful flight in 2012 gave us a new
  view of the corona at resolution approximately 4 times higher (linear
  dimension) than AIA. For example, it showed tantalizing evidence of
  coronal heating by braiding of field lines. LMSAL and SAO have designed
  a payload that goes beyond the basic requirements for T-07 by combining
  an imager like Hi-C with a novel multi-slit EUV spectrograph that
  obtains complete line profiles in three coronal temperature ranges over
  an extended field-of-view (FOV). This payload is MUSE, the Multi-Slit
  Solar Explorer, a Small Explorer mission recently selected by NASA
  for a Phase A study, which could lead to a launch in 2022. MUSE will
  provide unprecendented observations of the dynamics of the corona and
  transition region to illuminate the physical processes that heat the
  multi-million degree solar corona, accelerate the solar wind and drive
  solar activity (CMEs and flares). Using multi-slit coronal spectroscopy
  MUSE will exploit a 100x improvement in spectral raster cadence to
  reveal temperatures, velocities and non-thermal processes over a wide
  temperature range to diagnose physical processes that remain invisible
  to current or planned instruments. MUSE will obtain simultaneous EUV
  spectra and images with the highest resolution in space (1/3 arcsec)
  and time (1-4 s) ever achieved for the transition region and corona,
  along 35 slits over a FOV similar to that of IRIS, and a larger context
  imager FOV. The MUSE science investigation will exploit recent advances
  in numerical modeling and build on the success of IRIS by combining
  numerical modeling with a uniquely capable observatory. The MUSE
  consortium is led by LMSAL and includes SAO, MSU, ITA Oslo, Stanford,
  ARC, GSFC, MSFC and other institutions.

Title: Motions in Prominence Barbs Observed on the Solar Limb
Authors: Kucera, Therese Ann; Ofman, Leon; Tarbell, Theodore D.
Bibcode: 2018tess.conf21059K
Altcode:
  We analyze and discuss an example of prominence barbs observed on the

Title: Observations of Large Penumbral Jets from IRIS and Hinode
Authors: Tiwari, Sanjiv K.; Moore, Ronald Lee; De Pontieu, Bart;
   Tarbell, Theodore D.; Panesar, Navdeep Kaur; Winebarger, Amy R.;
   Sterling, Alphonse C.
Bibcode: 2018tess.conf40807T
Altcode:
  Recent observations from Hinode (SOT/FG) revealed the presence of
  large penumbral jets (widths ≥ 500 km, larger than normal penumbral
  microjets, which have widths &lt; 400 km) repeatedly occurring at
  the same locations in a sunspot penumbra, at the tail of a penumbral
  filament or where the tails of several penumbral filaments apparently
  converge (Tiwari et al. 2016, ApJ). These locations were observed
  to have mixed-polarity flux in Stokes-V images from SOT/FG. Large
  penumbral jets displayed direct signatures in AIA 1600, 304, 171,
  and 193 channels; thus they were heated to at least transition region
  temperatures. Because large jets could not be detected in AIA 94 Å,
  whether they had any coronal-temperature plasma remains unclear. In
  the present work, for another sunspot, we use IRIS Mg II k 2796
  slit jaw images and spectra and magnetograms from Hinode SOT/FG and
  SOT/SP to examine: whether penumbral jets spin, similar to spicules
  and coronal jets in the quiet Sun and coronal holes; whether they stem
  from mixed-polarity flux; and whether they produce discernible coronal
  emission, especially in AIA 94 Å images.

Title: MUSE, the Multi-Slit Solar Explorer
Authors: Lemen, J. R.; Tarbell, T. D.; De Pontieu, B.; Wuelser, J. P.
Bibcode: 2017AGUFMSH51B2494L
Altcode:
  The Multi-Slit Solar Explorer (MUSE) has been selected for a Phase A
  study for the NASA Heliophysics Small Explorer program. The science
  objective of MUSE is to make high spatial and temporal resolution
  imaging and spectral observations of the solar corona and transition
  region in order to probe the mechanisms responsible for energy release
  in the corona and understand the dynamics of the solar atmosphere. The
  physical processes are responsible for heating the corona, accelerating
  the solar wind, and the rapid release of energy in CMEs and flares. The
  observations will be tightly coupled to state-of-the-art numerical
  modeling to provide significantly improved estimates for understanding
  and anticipating space weather. MUSE contains two instruments:
  an EUV spectrograph and an EUV context imager. Both have similar
  spatial resolutions and leverage extensive heritage from previous
  high-resolution instruments such as IRIS and the HiC rocket payload. The
  MUSE spectrograph employs a novel multi-slit design that enables a
  100x improvement in spectral scanning rates, which will reveal crucial
  information about the dynamics (e.g., temperature, velocities) of the
  physical processes that are not observable with current instruments. The
  MUSE investigation builds on the success of IRIS by combining numerical
  modeling with a uniquely capable observatory: MUSE will obtain EUV
  spectra and images with the highest resolution in space (1/3 arcsec) and
  time (1-4 s) ever achieved for the transition region and corona, along
  35 slits and a large context FOV simultaneously. The MUSE consortium
  includes LMSAL, SAO, Stanford, ARC, HAO, GSFC, MSFC, MSU, and ITA Oslo.

Title: A New Approach to Observing Coronal Dynamics: MUSE, the
    Multi-Slit Solar Explorer
Authors: Tarbell, T. D.
Bibcode: 2017AGUFMSH41C..08T
Altcode:
  The Multi-Slit Solar Explorer is a Small Explorer mission recently
  selected for a Phase A study, which could lead to a launch in 2022. It
  will provide unprecendented observations of the dynamics of the corona
  and transition region using both conventional and novel spectral imaging
  techniques. The physical processes that heat the multi-million degree
  solar corona, accelerate the solar wind and drive solar activity (CMEs
  and flares) remain poorly known. A breakthrough in these areas can only
  come from radically innovative instrumentation and state-of-the-art
  numerical modeling and will lead to better understanding of space
  weather origins. MUSE's multi-slit coronal spectroscopy will exploit a
  100x improvement in spectral raster cadence to fill a crucial gap in
  our knowledge of Sun-Earth connections; it will reveal temperatures,
  velocities and non-thermal processes over a wide temperature range to
  diagnose physical processes that remain invisible to current or planned
  instruments. MUSE will contain two instruments: an EUV spectrograph (SG)
  and EUV context imager (CI). Both have similar spatial resolution and
  leverage extensive heritage from previous high-resolution instruments
  such as IRIS and the HiC rocket payload. The MUSE investigation will
  build on the success of IRIS by combining numerical modeling with a
  uniquely capable observatory: MUSE will obtain EUV spectra and images
  with the highest resolution in space (1/3 arcsec) and time (1-4 s)
  ever achieved for the transition region and corona, along 35 slits
  and a large context FOV simultaneously. The MUSE consortium includes
  LMSAL, SAO, Stanford, ARC, HAO, GSFC, MSFC, MSU, ITA Oslo and other
  institutions.

Title: MUSE: the Multi-Slit Solar Explorer
Authors: Tarbell, Theodore D.; De Pontieu, Bart
Bibcode: 2017SPD....4811008T
Altcode:
  The Multi-Slit Solar Explorer is a proposed Small Explorer mission
  for studying the dynamics of the corona and transition region
  using both conventional and novel spectral imaging techniques. The
  physical processes that heat the multi-million degree solar corona,
  accelerate the solar wind and drive solar activity (CMEs and flares)
  remain poorly known. A breakthrough in these areas can only come
  from radically innovative instrumentation and state-of-the-art
  numerical modeling and will lead to better understanding of space
  weather origins. MUSE’s multi-slit coronal spectroscopy will use a
  100x improvement in spectral raster cadence to fill a crucial gap in
  our knowledge of Sun-Earth connections; it will reveal temperatures,
  velocities and non-thermal processes over a wide temperature range to
  diagnose physical processes that remain invisible to current or planned
  instruments. MUSE will contain two instruments: an EUV spectrograph (SG)
  and EUV context imager (CI). Both have similar spatial resolution and
  leverage extensive heritage from previous high-resolution instruments
  such as IRIS and the HiC rocket payload. The MUSE investigation will
  build on the success of IRIS by combining numerical modeling with a
  uniquely capable observatory: MUSE will obtain EUV spectra and images
  with the highest resolution in space (1/3 arcsec) and time (1-4 s)
  ever achieved for the transition region and corona, along 35 slits
  and a large context FOV simultaneously. The MUSE consortium includes
  LMSAL, SAO, Stanford, ARC, HAO, GSFC, MSFC, MSU, ITA Oslo and other
  institutions.

Title: Evidence from IRIS that Sunspot Large Penumbral Jets Spin
Authors: Tiwari, Sanjiv K.; Moore, Ronald L.; De Pontieu, Bart;
   Tarbell, Theodore D.; Panesar, Navdeep K.; Winebarger, Amy; Sterling,
   Alphonse C.
Bibcode: 2017SPD....4810506T
Altcode:
  Recent observations from {\it Hinode} (SOT/FG) revealed the presence of
  large penumbral jets (widths $\ge$500 km, larger than normal penumbral
  microjets, which have widths $&lt;$ 400 km) repeatedly occurring at the
  same locations in a sunspot penumbra, at the tail of a filament or where
  the tails of several penumbral filaments apparently converge (Tiwari et
  al. 2016, ApJ). These locations were observed to have mixed-polarity
  flux in Stokes-V images from SOT/FG. Large penumbral jets displayed
  direct signatures in AIA 1600, 304, 171, and 193 channels; thus they
  were heated to at least transition region temperatures. Because
  large jets could not be detected in AIA 94 \AA, whether they had
  any coronal-temperature plasma remains unclear. In the present work,
  for another sunspot, we use IRIS Mg II k 2796 Å slit jaw images and
  spectra and magnetograms from Hinode SOT/FG and SOT/SP to examine:
  whether penumbral jets spin, similar to spicules and coronal jets in the
  quiet Sun and coronal holes; whether they stem from mixed-polarity flux;
  and whether they produce discernible coronal emission, especially in
  AIA 94 Å images. The few large penumbral jets for which we have IRIS
  spectra show evidence of spin. If these have mixed-polarity at their
  base, then they might be driven the same way as coronal jets and CMEs.

Title: An innovative browser-based data exploration tool with
    simultaneous scrolling in time and wavelength domains
Authors: Slater, Gregory L.; Schiff, David; De Pontieu, Bart; Tarbell,
   Theodore D.; Freeland, Samuel L.
Bibcode: 2017SPD....4810624S
Altcode:
  We present Cruiser, a new web tool for the precision interactive
  blending of image series across time and wavelength domains. Scrolling
  in two dimensions enables discovery and investigation of similarities
  and differences in structure and evolution across multiple
  wavelengths. Cruiser works in the latest versions of standards compliant
  browsers on both desktop and IOS platforms. Co-aligned data cubes
  have been generated for AIA, IRIS, and Hinode SOT FG, and image data
  from additional instruments, both space-based and ground-based, can be
  data sources. The tool has several movie playing and image adjustment
  controls which will be described in the poster and demonstrated on a
  MacOS notebook and iPad.

Title: MHD Waves at Umbral-Penumbral Boundary Observed with
    Hinode/SOT-SP and SDO/HMI
Authors: Norton, A. A.; Tarbell, T. D.; Scherrer, P. H.; Baldner, C. S.
Bibcode: 2016usc..confE.114N
Altcode:
  The conversion of p-modes and other perturbations in the near-surface
  layers into MHD waves that can propagate along and across magnetic field
  lines is a topic of interest for energy transport. The photospheric
  signatures of MHD waves are weak due to low amplitudes at the
  beta=1 equipartion level where mode-conversion occurs. We report on
  oscillations observed with Hinode SOT/SP and HMI in which we have time
  series for sunspots 12186 (11.10.2014) and 12434 (17.10.2015). In
  the Milne-Eddington inversion results from SP, oscillations in the
  inclination angle and velocity are found at the umbral-penumbral
  boundary with 5 minute periods. HMI data also shows distinct
  umbral-penumbral boundary oscillations consistent with the SP data. We
  discuss surface versus body modes that might explain these observations.

Title: Hinode SOT Images Coaligned with IRIS Level 2 Data Products
Authors: Tarbell, Theodore D.
Bibcode: 2016SPD....4710402T
Altcode:
  We have produced new data products consisting of HInode SOT images
  coaligned with simultaneous observations by IRIS. Cross-correlation
  between SOT Filtergraph images and similar SDO wavelength bands provides
  accurate pointing coordinates for nearly all SOT images, correcting
  for the solar flows followed by the SOT correlation tracker. Data
  from all of 2014 and 2015 and part of 2013 have been processed by now
  and verification of the data products is ongoing. The cubes of SOT
  images are created in IRIS level 2 data format and can be read using
  IRIS software tools. In addition, the SOT cubes can be studied using
  CRISPEX along with the corresponding IRIS Level 3 data. Work has begun
  to process time series of SOT Spectro-Polarimeter data into cubes of
  images that can be studied the same way. Examples of some datasets
  from IHOPs, both FG and SP, will be shown and instructions given for
  accessing and viewing the available datasets.

Title: Motions in Prominence Barbs as observed by Hinode/SOT and IRIS
Authors: Kucera, Therese A.; Ofman, Leon; Tarbell, Theodore D.
Bibcode: 2016SPD....47.0316K
Altcode:
  We discuss observations of prominence barb dynamics as observed by
  Hinode/SOT and IRIS. Prominence barbs extend outwards to the side of the
  main prominence spine and downwards towards the chromosphere. Their
  properties, including the structure of their magnetic field and
  the nature of the motions observed in them are a subject of current
  debate. We use a combination of high cadence, high resolution imaging,
  H-alpha Doppler, and Mg II line profile data to analyze and understand
  waves and flows in barbs and discuss their ramifications in terms of
  a model of the barb magnetic field as collection of dipped field lines.

Title: Comparing Dynamics in Eruptive and Non-Eruptive Flares
Authors: Nitta, Nariaki; Tarbell, Theodore D.; Slater, Gregory L.;
   Frank, Zoe Anne
Bibcode: 2016SPD....47.0620N
Altcode:
  Close comparison of EUV and coronagraph data suggests that there may
  not be clear distinction between eruptive and non-eruptive flares as
  far as the coronal and chromospheric signatures are concerned. Here we
  define eruptive and non-eruptive flares in terms of the presence and
  absence of the associated coronal mass ejection (CME). We have studied
  several flares in both categories using Hinode/SOT and IRIS data. The
  pointing of the Hinode/SOT data has been updated by correlating
  them with AIA 1700 A images. We show our initial results about how
  the flare development compares in eruptive and non-eruptive flares,
  including the reconnection rate as derived from the magnetic field
  swept over by flare ribbons (in SOT Ca images), and the line-of-sight
  velocities at different locations and temperatures (in IRIS spectral
  data). We also discuss large-scale disturbances and related CMEs in
  SDO/AIA and SOHO/LASCO data as context information.

Title: Amplitudes of MHD Waves in Sunspots
Authors: Norton, Aimee Ann; Cally, Paul; Baldner, Charles; Kleint,
   Lucia; Tarbell, Theodore D.; De Pontieu, Bart; Scherrer, Philip H.;
   Rajaguru, Paul
Bibcode: 2016SPD....47.1009N
Altcode:
  The conversion of p-modes into MHD waves by strong magnetic fields
  occurs mainly in the sub-photospheric layers. The photospheric
  signatures of MHD waves are weak due to low amplitudes at the beta=1
  equipartion level where mode-conversion occurs. We report on small
  amplitude oscillations observed in the photosphere with Hinode SOT/SP
  in which we analyze time series for sunspots ARs 12186 (11.10.2014)
  and 12434 (17.10.2015). No significant magnetic field oscillations
  are recovered in the umbra or penumbra in the ME inversion. However,
  periodicities in the inclination angle are found at the umbral/penumbral
  boundary with 5 minute periods. Upward propagating waves are indicated
  in the intensity signals correlated between HMI and AIA at different
  heights. We compare SP results with the oscillations observed in HMI
  data. Simultaneous IRIS data shows transition region brightening above
  the umbral core.

Title: Internetwork Chromospheric Bright Grains Observed With IRIS
    and SST
Authors: Martínez-Sykora, Juan; Rouppe van der Voort, Luc; Carlsson,
   Mats; De Pontieu, Bart; Pereira, Tiago M. D.; Boerner, Paul; Hurlburt,
   Neal; Kleint, Lucia; Lemen, James; Tarbell, Ted D.; Title, Alan;
   Wuelser, Jean-Pierre; Hansteen, Viggo H.; Golub, Leon; McKillop, Sean;
   Reeves, Kathy K.; Saar, Steven; Testa, Paola; Tian, Hui; Jaeggli,
   Sarah; Kankelborg, Charles
Bibcode: 2015ApJ...803...44M
Altcode: 2015arXiv150203490M
  The Interface Region Imaging Spectrograph (IRIS) reveals small-scale
  rapid brightenings in the form of bright grains all over coronal holes
  and the quiet Sun. These bright grains are seen with the IRIS 1330,
  1400, and 2796 Å slit-jaw filters. We combine coordinated observations
  with IRIS and from the ground with the Swedish 1 m Solar Telescope
  (SST) which allows us to have chromospheric (Ca ii 8542 Å, Ca ii H
  3968 Å, Hα, and Mg ii k 2796 Å) and transition region (C ii 1334 Å,
  Si iv 1403 Å) spectral imaging, and single-wavelength Stokes maps
  in Fe i 6302 Å at high spatial (0\buildrel{\prime\prime}\over{.}
  33), temporal, and spectral resolution. We conclude that the IRIS
  slit-jaw grains are the counterpart of so-called acoustic grains,
  i.e., resulting from chromospheric acoustic waves in a non-magnetic
  environment. We compare slit-jaw images (SJIs) with spectra from the
  IRIS spectrograph. We conclude that the grain intensity in the 2796
  Å slit-jaw filter comes from both the Mg ii k core and wings. The
  signal in the C ii and Si iv lines is too weak to explain the presence
  of grains in the 1300 and 1400 Å SJIs and we conclude that the grain
  signal in these passbands comes mostly from the continuum. Although
  weak, the characteristic shock signatures of acoustic grains can often
  be detected in IRIS C ii spectra. For some grains, a spectral signature
  can be found in IRIS Si iv. This suggests that upward propagating
  acoustic waves sometimes reach all the way up to the transition region.

Title: Homologous Helical Jets: Observations By IRIS, SDO, and Hinode
    and Magnetic Modeling With Data-Driven Simulations
Authors: Cheung, Mark C. M.; De Pontieu, B.; Tarbell, T. D.; Fu, Y.;
   Tian, H.; Testa, P.; Reeves, K. K.; Martínez-Sykora, J.; Boerner,
   P.; Wülser, J. P.; Lemen, J.; Title, A. M.; Hurlburt, N.; Kleint,
   L.; Kankelborg, C.; Jaeggli, S.; Golub, L.; McKillop, S.; Saar, S.;
   Carlsson, M.; Hansteen, V.
Bibcode: 2015ApJ...801...83C
Altcode: 2015arXiv150101593C
  We report on observations of recurrent jets by instruments on board
  the Interface Region Imaging Spectrograph, Solar Dynamics Observatory
  (SDO), and Hinode spacecraft. Over a 4 hr period on 2013 July 21,
  recurrent coronal jets were observed to emanate from NOAA Active Region
  11793. Far-ultraviolet spectra probing plasma at transition region
  temperatures show evidence of oppositely directed flows with components
  reaching Doppler velocities of ±100 km s<SUP>-1</SUP>. Raster Doppler
  maps using a Si iv transition region line show all four jets to have
  helical motion of the same sense. Simultaneous observations of the
  region by SDO and Hinode show that the jets emanate from a source
  region comprising a pore embedded in the interior of a supergranule. The
  parasitic pore has opposite polarity flux compared to the surrounding
  network field. This leads to a spine-fan magnetic topology in the
  coronal field that is amenable to jet formation. Time-dependent
  data-driven simulations are used to investigate the underlying drivers
  for the jets. These numerical experiments show that the emergence of
  current-carrying magnetic field in the vicinity of the pore supplies
  the magnetic twist needed for recurrent helical jet formation.

Title: Homologous Helical Jets: Observations by IRIS, SDO and Hinode
    and Data-Driven Simulations
Authors: Cheung, C. M. M.; De Pontieu, B.; Tarbell, T. D.; Fu, Y.
Bibcode: 2014AGUFMSH53D..05C
Altcode:
  We report on observations of recurrent jets by instruments onboard
  the Interface Region Imaging Spectrograph (IRIS), Solar Dynamics
  Observatory (SDO) and Hinode spacecrafts. Over a 4-hour period on
  July 21st 2013, recurrent coronal jets were observed to emanate from
  NOAA Active Region 11793. In more than one instance, double-peaked
  FUV spectra probing plasma at transition region temperatures show
  evidence of oppositely directed (Doppler) outflows exceeding +/- 100
  km/s. Raster Doppler maps using a Si IV transition region line shows
  all four jets to have helical motion of the same sense. Time-dependent
  data-driven simulations are used to investigate the underlying drivers
  for the jets. These numerical experiments show that the emergence of
  current-carrying magnetic field in the vicinity of a pore supplies
  the magnetic twist needed for recurrent helical jet formation.

Title: Hot explosions in the cool atmosphere of the Sun
Authors: Peter, H.; Tian, H.; Curdt, W.; Schmit, D.; Innes, D.;
   De Pontieu, B.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.;
   Tarbell, T. D.; Wuelser, J. P.; Martínez-Sykora, Juan; Kleint,
   L.; Golub, L.; McKillop, S.; Reeves, K. K.; Saar, S.; Testa, P.;
   Kankelborg, C.; Jaeggli, S.; Carlsson, M.; Hansteen, V.
Bibcode: 2014Sci...346C.315P
Altcode: 2014arXiv1410.5842P
  The solar atmosphere was traditionally represented with a simple
  one-dimensional model. Over the past few decades, this paradigm shifted
  for the chromosphere and corona that constitute the outer atmosphere,
  which is now considered a dynamic structured envelope. Recent
  observations by the Interface Region Imaging Spectrograph (IRIS) reveal
  that it is difficult to determine what is up and down, even in the cool
  6000-kelvin photosphere just above the solar surface: This region hosts
  pockets of hot plasma transiently heated to almost 100,000 kelvin. The
  energy to heat and accelerate the plasma requires a considerable
  fraction of the energy from flares, the largest solar disruptions. These
  IRIS observations not only confirm that the photosphere is more complex
  than conventionally thought, but also provide insight into the energy
  conversion in the process of magnetic reconnection.

Title: The unresolved fine structure resolved: IRIS observations of
    the solar transition region
Authors: Hansteen, V.; De Pontieu, B.; Carlsson, M.; Lemen, J.; Title,
   A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser, J. P.; Pereira,
   T. M. D.; De Luca, E. E.; Golub, L.; McKillop, S.; Reeves, K.; Saar,
   S.; Testa, P.; Tian, H.; Kankelborg, C.; Jaeggli, S.; Kleint, L.;
   Martínez-Sykora, J.
Bibcode: 2014Sci...346E.315H
Altcode: 2014arXiv1412.3611H
  The heating of the outer solar atmospheric layers, i.e., the transition
  region and corona, to high temperatures is a long-standing problem
  in solar (and stellar) physics. Solutions have been hampered by an
  incomplete understanding of the magnetically controlled structure of
  these regions. The high spatial and temporal resolution observations
  with the Interface Region Imaging Spectrograph (IRIS) at the solar
  limb reveal a plethora of short, low-lying loops or loop segments
  at transition-region temperatures that vary rapidly, on the time
  scales of minutes. We argue that the existence of these loops solves
  a long-standing observational mystery. At the same time, based on
  comparison with numerical models, this detection sheds light on a
  critical piece of the coronal heating puzzle.

Title: Evidence of nonthermal particles in coronal loops heated
    impulsively by nanoflares
Authors: Testa, P.; De Pontieu, B.; Allred, J.; Carlsson, M.; Reale,
   F.; Daw, A.; Hansteen, V.; Martinez-Sykora, J.; Liu, W.; DeLuca, E. E.;
   Golub, L.; McKillop, S.; Reeves, K.; Saar, S.; Tian, H.; Lemen, J.;
   Title, A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser, J. P.;
   Kleint, L.; Kankelborg, C.; Jaeggli, S.
Bibcode: 2014Sci...346B.315T
Altcode: 2014arXiv1410.6130T
  The physical processes causing energy exchange between the Sun’s
  hot corona and its cool lower atmosphere remain poorly understood. The
  chromosphere and transition region (TR) form an interface region between
  the surface and the corona that is highly sensitive to the coronal
  heating mechanism. High-resolution observations with the Interface
  Region Imaging Spectrograph (IRIS) reveal rapid variability (~20 to
  60 seconds) of intensity and velocity on small spatial scales (≲500
  kilometers) at the footpoints of hot and dynamic coronal loops. The
  observations are consistent with numerical simulations of heating by
  beams of nonthermal electrons, which are generated in small impulsive
  (≲30 seconds) heating events called “coronal nanoflares.” The
  accelerated electrons deposit a sizable fraction of their energy
  (≲10<SUP>25 </SUP>erg) in the chromosphere and TR. Our analysis
  provides tight constraints on the properties of such electron beams
  and new diagnostics for their presence in the nonflaring corona.

Title: Prevalence of small-scale jets from the networks of the solar
    transition region and chromosphere
Authors: Tian, H.; DeLuca, E. E.; Cranmer, S. R.; De Pontieu, B.;
   Peter, H.; Martínez-Sykora, J.; Golub, L.; McKillop, S.; Reeves,
   K. K.; Miralles, M. P.; McCauley, P.; Saar, S.; Testa, P.; Weber,
   M.; Murphy, N.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt, N.;
   Tarbell, T. D.; Wuelser, J. P.; Kleint, L.; Kankelborg, C.; Jaeggli,
   S.; Carlsson, M.; Hansteen, V.; McIntosh, S. W.
Bibcode: 2014Sci...346A.315T
Altcode: 2014arXiv1410.6143T
  As the interface between the Sun’s photosphere and corona, the
  chromosphere and transition region play a key role in the formation and
  acceleration of the solar wind. Observations from the Interface Region
  Imaging Spectrograph reveal the prevalence of intermittent small-scale
  jets with speeds of 80 to 250 kilometers per second from the narrow
  bright network lanes of this interface region. These jets have lifetimes
  of 20 to 80 seconds and widths of ≤300 kilometers. They originate from
  small-scale bright regions, often preceded by footpoint brightenings
  and accompanied by transverse waves with amplitudes of ~20 kilometers
  per second. Many jets reach temperatures of at least ~10<SUP>5</SUP>
  kelvin and constitute an important element of the transition region
  structures. They are likely an intermittent but persistent source of
  mass and energy for the solar wind.

Title: On the prevalence of small-scale twist in the solar
    chromosphere and transition region
Authors: De Pontieu, B.; Rouppe van der Voort, L.; McIntosh, S. W.;
   Pereira, T. M. D.; Carlsson, M.; Hansteen, V.; Skogsrud, H.; Lemen,
   J.; Title, A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser,
   J. P.; De Luca, E. E.; Golub, L.; McKillop, S.; Reeves, K.; Saar,
   S.; Testa, P.; Tian, H.; Kankelborg, C.; Jaeggli, S.; Kleint, L.;
   Martinez-Sykora, J.
Bibcode: 2014Sci...346D.315D
Altcode: 2014arXiv1410.6862D
  The solar chromosphere and transition region (TR) form an interface
  between the Sun’s surface and its hot outer atmosphere. There,
  most of the nonthermal energy that powers the solar atmosphere
  is transformed into heat, although the detailed mechanism remains
  elusive. High-resolution (0.33-arc second) observations with NASA’s
  Interface Region Imaging Spectrograph (IRIS) reveal a chromosphere
  and TR that are replete with twist or torsional motions on sub-arc
  second scales, occurring in active regions, quiet Sun regions, and
  coronal holes alike. We coordinated observations with the Swedish
  1-meter Solar Telescope (SST) to quantify these twisting motions and
  their association with rapid heating to at least TR temperatures. This
  view of the interface region provides insight into what heats the low
  solar atmosphere.

Title: An Interface Region Imaging Spectrograph First View on Solar
    Spicules
Authors: Pereira, T. M. D.; De Pontieu, B.; Carlsson, M.; Hansteen,
   V.; Tarbell, T. D.; Lemen, J.; Title, A.; Boerner, P.; Hurlburt,
   N.; Wülser, J. P.; Martínez-Sykora, J.; Kleint, L.; Golub, L.;
   McKillop, S.; Reeves, K. K.; Saar, S.; Testa, P.; Tian, H.; Jaeggli,
   S.; Kankelborg, C.
Bibcode: 2014ApJ...792L..15P
Altcode: 2014arXiv1407.6360P
  Solar spicules have eluded modelers and observers for decades. Since
  the discovery of the more energetic type II, spicules have become
  a heated topic but their contribution to the energy balance of the
  low solar atmosphere remains unknown. Here we give a first glimpse of
  what quiet-Sun spicules look like when observed with NASA's recently
  launched Interface Region Imaging Spectrograph (IRIS). Using IRIS
  spectra and filtergrams that sample the chromosphere and transition
  region, we compare the properties and evolution of spicules as
  observed in a coordinated campaign with Hinode and the Atmospheric
  Imaging Assembly. Our IRIS observations allow us to follow the thermal
  evolution of type II spicules and finally confirm that the fading
  of Ca II H spicules appears to be caused by rapid heating to higher
  temperatures. The IRIS spicules do not fade but continue evolving,
  reaching higher and falling back down after 500-800 s. Ca II H type
  II spicules are thus the initial stages of violent and hotter events
  that mostly remain invisible in Ca II H filtergrams. These events
  have very different properties from type I spicules, which show lower
  velocities and no fading from chromospheric passbands. The IRIS spectra
  of spicules show the same signature as their proposed disk counterparts,
  reinforcing earlier work. Spectroheliograms from spectral rasters also
  confirm that quiet-Sun spicules originate in bushes from the magnetic
  network. Our results suggest that type II spicules are indeed the
  site of vigorous heating (to at least transition region temperatures)
  along extensive parts of the upward moving spicular plasma.

Title: The Interface Region Imaging Spectrograph (IRIS)
Authors: De Pontieu, B.; Title, A. M.; Lemen, J. R.; Kushner, G. D.;
   Akin, D. J.; Allard, B.; Berger, T.; Boerner, P.; Cheung, M.; Chou,
   C.; Drake, J. F.; Duncan, D. W.; Freeland, S.; Heyman, G. F.; Hoffman,
   C.; Hurlburt, N. E.; Lindgren, R. W.; Mathur, D.; Rehse, R.; Sabolish,
   D.; Seguin, R.; Schrijver, C. J.; Tarbell, T. D.; Wülser, J. -P.;
   Wolfson, C. J.; Yanari, C.; Mudge, J.; Nguyen-Phuc, N.; Timmons,
   R.; van Bezooijen, R.; Weingrod, I.; Brookner, R.; Butcher, G.;
   Dougherty, B.; Eder, J.; Knagenhjelm, V.; Larsen, S.; Mansir, D.;
   Phan, L.; Boyle, P.; Cheimets, P. N.; DeLuca, E. E.; Golub, L.;
   Gates, R.; Hertz, E.; McKillop, S.; Park, S.; Perry, T.; Podgorski,
   W. A.; Reeves, K.; Saar, S.; Testa, P.; Tian, H.; Weber, M.; Dunn, C.;
   Eccles, S.; Jaeggli, S. A.; Kankelborg, C. C.; Mashburn, K.; Pust, N.;
   Springer, L.; Carvalho, R.; Kleint, L.; Marmie, J.; Mazmanian, E.;
   Pereira, T. M. D.; Sawyer, S.; Strong, J.; Worden, S. P.; Carlsson,
   M.; Hansteen, V. H.; Leenaarts, J.; Wiesmann, M.; Aloise, J.; Chu,
   K. -C.; Bush, R. I.; Scherrer, P. H.; Brekke, P.; Martinez-Sykora,
   J.; Lites, B. W.; McIntosh, S. W.; Uitenbroek, H.; Okamoto, T. J.;
   Gummin, M. A.; Auker, G.; Jerram, P.; Pool, P.; Waltham, N.
Bibcode: 2014SoPh..289.2733D
Altcode: 2014arXiv1401.2491D; 2014SoPh..tmp...25D
  The Interface Region Imaging Spectrograph (IRIS) small explorer
  spacecraft provides simultaneous spectra and images of the photosphere,
  chromosphere, transition region, and corona with 0.33 - 0.4 arcsec
  spatial resolution, two-second temporal resolution, and 1 km
  s<SUP>−1</SUP> velocity resolution over a field-of-view of up to
  175 arcsec × 175 arcsec. IRIS was launched into a Sun-synchronous
  orbit on 27 June 2013 using a Pegasus-XL rocket and consists of a
  19-cm UV telescope that feeds a slit-based dual-bandpass imaging
  spectrograph. IRIS obtains spectra in passbands from 1332 - 1358 Å,
  1389 - 1407 Å, and 2783 - 2834 Å, including bright spectral lines
  formed in the chromosphere (Mg II h 2803 Å and Mg II k 2796 Å) and
  transition region (C II 1334/1335 Å and Si IV 1394/1403 Å). Slit-jaw
  images in four different passbands (C II 1330, Si IV 1400, Mg II k
  2796, and Mg II wing 2830 Å) can be taken simultaneously with spectral
  rasters that sample regions up to 130 arcsec × 175 arcsec at a variety
  of spatial samplings (from 0.33 arcsec and up). IRIS is sensitive to
  emission from plasma at temperatures between 5000 K and 10 MK and will
  advance our understanding of the flow of mass and energy through an
  interface region, formed by the chromosphere and transition region,
  between the photosphere and corona. This highly structured and dynamic
  region not only acts as the conduit of all mass and energy feeding
  into the corona and solar wind, it also requires an order of magnitude
  more energy to heat than the corona and solar wind combined. The
  IRIS investigation includes a strong numerical modeling component
  based on advanced radiative-MHD codes to facilitate interpretation of
  observations of this complex region. Approximately eight Gbytes of data
  (after compression) are acquired by IRIS each day and made available
  for unrestricted use within a few days of the observation.

Title: Detection of Supersonic Downflows and Associated Heating
    Events in the Transition Region above Sunspots
Authors: Kleint, L.; Antolin, P.; Tian, H.; Judge, P.; Testa, P.;
   De Pontieu, B.; Martínez-Sykora, J.; Reeves, K. K.; Wuelser, J. P.;
   McKillop, S.; Saar, S.; Carlsson, M.; Boerner, P.; Hurlburt, N.; Lemen,
   J.; Tarbell, T. D.; Title, A.; Golub, L.; Hansteen, V.; Jaeggli, S.;
   Kankelborg, C.
Bibcode: 2014ApJ...789L..42K
Altcode: 2014arXiv1406.6816K
  Interface Region Imaging Spectrograph data allow us to study the solar
  transition region (TR) with an unprecedented spatial resolution of
  0.''33. On 2013 August 30, we observed bursts of high Doppler shifts
  suggesting strong supersonic downflows of up to 200 km s<SUP>-1</SUP>
  and weaker, slightly slower upflows in the spectral lines Mg II h
  and k, C II 1336, Si IV 1394 Å, and 1403 Å, that are correlated
  with brightenings in the slitjaw images (SJIs). The bursty behavior
  lasts throughout the 2 hr observation, with average burst durations
  of about 20 s. The locations of these short-lived events appear to
  be the umbral and penumbral footpoints of EUV loops. Fast apparent
  downflows are observed along these loops in the SJIs and in the
  Atmospheric Imaging Assembly, suggesting that the loops are thermally
  unstable. We interpret the observations as cool material falling
  from coronal heights, and especially coronal rain produced along the
  thermally unstable loops, which leads to an increase of intensity
  at the loop footpoints, probably indicating an increase of density
  and temperature in the TR. The rain speeds are on the higher end of
  previously reported speeds for this phenomenon, and possibly higher
  than the free-fall velocity along the loops. On other observing days,
  similar bright dots are sometimes aligned into ribbons, resembling
  small flare ribbons. These observations provide a first insight into
  small-scale heating events in sunspots in the TR.

Title: Lockheed Solar Observatory and the Discovery of Moreton-Ramsey
    Waves
Authors: Tarbell, Theodore D.
Bibcode: 2014AAS...22420303T
Altcode:
  Moreton Waves are high-speed disturbances seen traveling away from
  large solar flares in H-alpha movies of the solar chromosphere. They
  were discovered by the observer Harry Ramsey in the late 1950s, and
  then published and publicized by the director Gail Moreton, both of
  the Lockheed Solar Observatory in the Hollywood Hills of Southern
  California. These efforts established the scientific reputation and
  secured continuing funding of the observatory, whose present-day
  successor is the Lockheed Martin Solar and Astrophysics Lab in Palo
  Alto. Moreton waves are rare, and there was limited interest in them
  until the EIT instrument on SOHO began seeing large numbers of similar
  waves in the corona in the late 1990s. The exact relation between
  the two observations is still a research topic today. This talk will
  describe some of the history of the observatory and the discovery and
  early interpretation of the waves.

Title: The SUVIT Instrument on the Solar-C Mission
Authors: Tarbell, Theodore D.; Ichimoto, Kiyoshi
Bibcode: 2014AAS...22412363T
Altcode:
  Solar-C is a new space mission being proposed to JAXA, with significant
  contributions anticipated from NASA, ESA, and EU countries. The main
  scientific objectives are to: reveal the mechanisms for heating and
  dynamics of the chromosphere and corona and acceleration of the solar
  wind; determine the physical origin of the large-scale explosions
  and eruptions that drive short-term solar, heliospheric, and geospace
  variability; use the solar atmosphere as a laboratory for understanding
  fundamental physical processes; make unprecedented observations
  of the polar magnetic fields. The unique approaches of Solar-C to
  achieve these goals are to: determine the properties and evolution of
  the 3-dimensional magnetic field, especially on small spatial scales,
  and for the first time observed in the crucial low beta plasma region;
  observe all the temperature regimes of the atmosphere seamlessly at
  the highest spatial resolution ever achieved; observe at high cadence
  the prevailing dynamics in all regions of the atmosphere; determine
  physical properties from high resolution spectroscopic measurements
  throughout the atmosphere and into the solar wind. The powerful suite
  of instruments onboard Solar-C will be sensitive to temperatures from
  the photosphere 5500 K) to solar flares 20 MK) with no temperature
  gap, with spatial resolution at all temperatures of 0.3″ or less
  (0.1″ in the lower atmosphere) and at high cadence. The purpose of
  the Solar UV-Visible-IR Telescope (SUVIT) is to obtain chromospheric
  velocity, temperature, density and magnetic field diagnostics
  over as wide arange of heights as possible, through high cadence
  spectral line profiles and vector spectro-polarimetry. SUVIT is a
  meter-class telescope currently under study at 1.4m in order to obtain
  sufficientresolution and S/N. SUVIT has two complementary focal plane
  packages, the Filtergraph that makes high cadence imaging observations
  with the highest spatial resolution and the Spectro-polarimeter that
  makes precise spectro-polarimetric observations. With their powerful
  sets of spectral lines, FG and SP collect physical measurements from
  the lower photosphere to upper chromosphere with much better spatial
  and temporal resolution than Hinode SOT.

Title: High-resolution Observations of the Shock Wave Behavior for
    Sunspot Oscillations with the Interface Region Imaging Spectrograph
Authors: Tian, H.; DeLuca, E.; Reeves, K. K.; McKillop, S.; De Pontieu,
   B.; Martínez-Sykora, J.; Carlsson, M.; Hansteen, V.; Kleint, L.;
   Cheung, M.; Golub, L.; Saar, S.; Testa, P.; Weber, M.; Lemen, J.;
   Title, A.; Boerner, P.; Hurlburt, N.; Tarbell, T. D.; Wuelser, J. P.;
   Kankelborg, C.; Jaeggli, S.; McIntosh, S. W.
Bibcode: 2014ApJ...786..137T
Altcode: 2014arXiv1404.6291T
  We present the first results of sunspot oscillations from observations
  by the Interface Region Imaging Spectrograph. The strongly nonlinear
  oscillation is identified in both the slit-jaw images and the
  spectra of several emission lines formed in the transition region and
  chromosphere. We first apply a single Gaussian fit to the profiles of
  the Mg II 2796.35 Å, C II 1335.71 Å, and Si IV 1393.76 Å lines in the
  sunspot. The intensity change is ~30%. The Doppler shift oscillation
  reveals a sawtooth pattern with an amplitude of ~10 km s<SUP>-1</SUP>
  in Si IV. The Si IV oscillation lags those of C II and Mg II by ~3 and
  ~12 s, respectively. The line width suddenly increases as the Doppler
  shift changes from redshift to blueshift. However, we demonstrate
  that this increase is caused by the superposition of two emission
  components. We then perform detailed analysis of the line profiles at
  a few selected locations on the slit. The temporal evolution of the
  line core is dominated by the following behavior: a rapid excursion
  to the blue side, accompanied by an intensity increase, followed by a
  linear decrease of the velocity to the red side. The maximum intensity
  slightly lags the maximum blueshift in Si IV, whereas the intensity
  enhancement slightly precedes the maximum blueshift in Mg II. We find
  a positive correlation between the maximum velocity and deceleration,
  a result that is consistent with numerical simulations of upward
  propagating magnetoacoustic shock waves.

Title: The Interface Region Imaging Spectrograph (IRIS)
Authors: De Pontieu, Bart; Title, A. M.; Lemen, J.; Wuelser, J.;
   Tarbell, T. D.; Schrijver, C. J.; Golub, L.; Kankelborg, C.; Carlsson,
   M.; Hansteen, V. H.; Worden, S.; IRIS Team
Bibcode: 2013SPD....44...03D
Altcode:
  The solar chromosphere and transition region (TR) form a highly
  structured and dynamic interface region between the photosphere and
  the corona. This region not only acts as the conduit of all mass and
  energy feeding into the corona and solar wind, it also requires an
  order of magnitude more energy to heat than the corona. Nevertheless,
  the chromosphere remains poorly understood, because of the complexity
  of the required observational and analytical tools: the interface
  region is highly complex with transitions from optically thick to
  optically thin radiation, from pressure to magnetic field domination,
  and large density and temperature contrasts on small spatial scales. The
  Interface Region Imaging Spectrograph (IRIS) was selected for a NASA
  SMEX mission in 2009 and is scheduled to launch on 26-June-2013 (with
  first light scheduled for mid July). IRIS addresses critical questions:
  (1) Which types of non-thermal energy dominate in the chromosphere and
  beyond? (2) How does the chromosphere regulate mass and energy supply
  to the corona and heliosphere? (3) How do magnetic flux and matter
  rise through the lower atmosphere, and what role does flux emergence
  play in flares and mass ejections? These questions are addressed with
  a high-resolution near and far UV imaging spectrometer sensitive to
  emission from plasma at temperatures between 5,000 K and 10 MK. IRIS
  has a field-of-view of 120 arcsec, a spatial resolution of 0.4 arcsec,
  and velocity resolution of 0.5 km/s. The IRIS investigation includes
  a strong numerical modeling component based on advanced radiative MHD
  codes to facilitate interpretation of observations. We describe the
  IRIS instrumentation and numerical modeling, and present the plans for
  observations, calibration and data distribution. We will highlight some
  of the issues that IRIS observations can help resolve. More information
  can be found at http://iris.lmsal.com

Title: The Hinode Spectro-Polarimeter
Authors: Lites, B. W.; Akin, D. L.; Card, G.; Cruz, T.; Duncan, D. W.;
   Edwards, C. G.; Elmore, D. F.; Hoffmann, C.; Katsukawa, Y.; Katz, N.;
   Kubo, M.; Ichimoto, K.; Shimizu, T.; Shine, R. A.; Streander, K. V.;
   Suematsu, A.; Tarbell, T. D.; Title, A. M.; Tsuneta, S.
Bibcode: 2013SoPh..283..579L
Altcode:
  The joint Japan/US/UK Hinode mission includes the first large-aperture
  visible-light solar telescope flown in space. One component of the
  Focal Plane Package of that telescope is a precision spectro-polarimeter
  designed to measure full Stokes spectra with the intent of using those
  spectra to infer the magnetic-field vector at high precision in the
  solar photosphere. This article describes the characteristics of the
  flight hardware of the HinodeSpectro-Polarimeter, and summarizes its
  in-flight performance.

Title: The Interface Region Imaging Spectrograph (IRIS)
Authors: De Pontieu, B.; Title, A. M.; Lemen, J. R.; Wuelser, J.;
   Tarbell, T. D.; Schrijver, C.; Golub, L.; Kankelborg, C. C.; Hansteen,
   V. H.; Carlsson, M.
Bibcode: 2012AGUFMSH33D2256D
Altcode:
  The solar chromosphere and transition region (TR) form a highly
  structured and dynamic interface region between the photosphere and
  the corona. This region not only acts as the conduit of all mass and
  energy feeding into the corona and solar wind, it also requires an
  order of magnitude more energy to heat than the corona. Nevertheless,
  the chromosphere remains poorly understood, because of the complexity
  of the required observational and analytical tools: the interface
  region is highly complex with transitions from optically thick to
  optically thin radiation, from pressure to magnetic field domination,
  and large density and temperature contrasts on small spatial scales. The
  Interface Region Imaging Spectrograph (IRIS) was selected for a NASA
  SMEX mission in 2009 and is scheduled to launch in early 2013. IRIS
  addresses critical questions: (1) Which types of non-thermal energy
  dominate in the chromosphere and beyond? (2) How does the chromosphere
  regulate mass and energy supply to the corona and heliosphere? (3)
  How do magnetic flux and matter rise through the lower atmosphere, and
  what role does flux emergence play in flares and mass ejections? These
  questions are addressed with a high-resolution near and far UV imaging
  spectrometer sensitive to emission from plasma at temperatures between
  5,000 K and 10 MK. IRIS has a field-of-view of 120 arcsec, a spatial
  resolution of 0.4 arcsec, and velocity resolution of 0.5 km/s. The
  IRIS investigation includes a strong numerical modeling component
  based on advanced radiative MHD codes to facilitate interpretation of
  observations. We will describe the IRIS instrumentation and numerical
  modeling, and present the status of the IRIS observatory development. We
  will highlight some of the issues that IRIS observations can help
  resolve.

Title: Interaction of Cometary Material With the Solar Corona:
    EUV Observations and MHD Simulations
Authors: Liu, W.; Jia, Y.; Downs, C.; Schrijver, C.; Saint-Hilaire,
   P.; Battams, K.; Tarbell, T. D.; Shine, R. A.
Bibcode: 2012AGUFMSH13B2254L
Altcode:
  Extreme ultraviolet (EUV) emission from two recent sun-grazing comets,
  C/2011 N3 and C/2011 W3 (Lovejoy), has been observed in the solar corona
  for the first time by the SDO/AIA and STEREO/EUVI instruments (Schrijver
  et al. 2011). These observations provided a unique opportunity to
  investigate the interaction of the cometary material with the solar
  corona and probe their physical conditions. We present here EUV
  observations and MHD simulations on this subject, focusing on the
  deceleration of the cometary tail material within the corona. We found
  that despite their different local coronal environments, the two comets
  exhibited quite similar characteristics. The initial EUV emitting tail
  had a projected velocity of 100-200 km/s, which was much lower than the
  orbital velocity of 500-600 km/s in the plane-of-sky. This indicates
  that significant deceleration had taken place while the tail material
  was heated to coronal temperatures on the order of 1 MK before it
  started to emit in EUV (Bryans &amp; Pesnell 2012). After its initial
  appearance, the tail further experienced a projected deceleration
  of ~1 km/s^2 (or 4 g_Sun). In particular, in the Lovejoy case, the
  tail appeared as clusters of bright parallel striations roughly at
  right angles to the orbit direction, suggestive of magnetic field
  lines illuminated by the plasma frozen onto them. These striations
  came to a stop and then accelerated in an opposite direction (seen
  in projection), approaching a constant velocity of ~50 km/s. These
  observations suggest that a Lorentz force from the coronal magnetic
  field was operating on the newly ionized cometary plasma. To test this
  hypothesis and understand tail deceleration mechanisms, we adopted a
  multi-fluid MHD model (Jia et al. 2012) to simulate the interaction
  between charged particles and the magnetized coronal plasma. We used
  potential extrapolation (Schrijver &amp; DeRosa 2003) and a more
  sophisticated global MHD model (Lionello et al. 2009) to infer the
  magnetic field and plasma conditions of the corona along the comet's
  orbit as inputs to the simulations. We will compare the observations and
  simulation results, and discuss the implications for using sun-grazing
  comets as probes to the solar corona in the context of NASA's future
  Solar Probe Plus mission.

Title: The interface region imaging spectrograph for the IRIS Small
    Explorer mission
Authors: Wülser, Jean-Pierre; Title, Alan M.; Lemen, James R.; De
   Pontieu, Bart; Kankelborg, Charles C.; Tarbell, Theodore D.; Berger,
   Thomas E.; Golub, Leon; Kushner, Gary D.; Chou, Catherine Y.; Weingrod,
   Isaac; Holmes, Buck; Mudge, Jason; Podgorski, William A.
Bibcode: 2012SPIE.8443E..08W
Altcode:
  The Interface Region Imaging Spectrograph (IRIS) is a NASA SMall
  EXplorer mission scheduled for launch in January 2013. The primary goal
  of IRIS is to understand how the solar atmosphere is energized. The
  IRIS investigation combines advanced numerical modeling with a high
  resolution UV imaging spectrograph. IRIS will obtain UV spectra
  and images with high resolution in space (0.4 arcsec) and time (1s)
  focused on the chromosphere and transition region of the Sun, a complex
  interface region between the photosphere and corona. The IRIS instrument
  uses a Cassegrain telescope to feed a dual spectrograph and slit-jaw
  imager that operate in the 133-141 nm and 278-283 nm ranges. This paper
  describes the instrument with emphasis on the imaging spectrograph,
  and presents an initial performance assessment from ground test results.

Title: Plasma Instabilities in Quiescent Prominences
Authors: Ryutova, M.; Berger, T.; Frank, Z.; Title, A.; Tarbell, T.
Bibcode: 2012ASPC..454..143R
Altcode:
  We study dynamics of quiescent prominences using several data sets
  taken with the SOT on Hinode. We find a number of processes occurring
  at different stages of the prominence evolution that are common for
  all the chosen cases, and having universal character, can be related
  to a fundamental plasma instabilities. We combine the observational
  evidence and theory to identify these instabilities. Here we discuss
  only two examples: (1) Coronal cavity formation under a prominence
  body and its evolution associated with screw pinch instability, and
  (2) Development of a regular series of plumes and spikes typical to
  the Rayleigh-Taylor instability modified by solenoidal magnetic field.

Title: Quasi-periodic Fast-mode Wave Trains within a Global EUV Wave
    and Sequential Transverse Oscillations Detected by SDO/AIA
Authors: Liu, Wei; Ofman, Leon; Nitta, Nariaki V.; Aschwanden, Markus
   J.; Schrijver, Carolus J.; Title, Alan M.; Tarbell, Theodore D.
Bibcode: 2012ApJ...753...52L
Altcode: 2012arXiv1204.5470L
  We present the first unambiguous detection of quasi-periodic wave
  trains within the broad pulse of a global EUV wave (so-called EIT wave)
  occurring on the limb. These wave trains, running ahead of the lateral
  coronal mass ejection (CME) front of 2-4 times slower, coherently
  travel to distances &gt;~ R <SUB>⊙</SUB>/2 along the solar surface,
  with initial velocities up to 1400 km s<SUP>-1</SUP> decelerating to
  ~650 km s<SUP>-1</SUP>. The rapid expansion of the CME initiated at
  an elevated height of 110 Mm produces a strong downward and lateral
  compression, which may play an important role in driving the primary
  EUV wave and shaping its front forwardly inclined toward the solar
  surface. The wave trains have a dominant 2 minute periodicity that
  matches the X-ray flare pulsations, suggesting a causal connection. The
  arrival of the leading EUV wave front at increasing distances produces
  an uninterrupted chain sequence of deflections and/or transverse (likely
  fast kink mode) oscillations of local structures, including a flux-rope
  coronal cavity and its embedded filament with delayed onsets consistent
  with the wave travel time at an elevated (by ~50%) velocity within
  it. This suggests that the EUV wave penetrates through a topological
  separatrix surface into the cavity, unexpected from CME-caused magnetic
  reconfiguration. These observations, when taken together, provide
  compelling evidence of the fast-mode MHD wave nature of the primary
  (outer) fast component of a global EUV wave, running ahead of the
  secondary (inner) slow component of CME-caused restructuring.

Title: The Journey of Sungrazing Comet Lovejoy
Authors: Bryans, Paul; A'Hearn, M.; Battams, K.; Biesecker, D.;
   Bodewits, D.; Boice, D.; Brown, J.; Caspi, A.; Chodas, P.; Hudson,
   H.; Jia, Y.; Jones, G.; Keller, H. U.; Knight, M.; Linker, J.; Lisse,
   C.; Liu, W.; McIntosh, S.; Pesnell, W. D.; Raymond, J.; Saar, S.;
   Saint-Hilaire, P.; Schrijver, C.; Snow, M.; Tarbell, T.; Thompson,
   W.; Weissman, P.; Comet Lovejoy Collaboration Team
Bibcode: 2012AAS...22052507B
Altcode:
  Comet Lovejoy (C/2011 W3) was the first sungrazing comet, observed
  by space-based instruments, to survive perihelion passage. First
  observed by ground-based telescopes several weeks prior to perihelion,
  its journey towards the Sun was subsequently recorded by several solar
  observatories, before being observed in the weeks after perihelion by
  a further array of space- and ground-based instruments. Such a surfeit
  of wide-ranging observations provides an unprecedented insight into
  both sungrazing comets themselves, and the solar atmosphere through
  which they pass. This paper will summarize what we have learnt from the
  observations thus far and offer some thoughts on what future sungrazing
  comets may reveal about comets, the Sun, and their interaction.

Title: SDO/AIA Detection of Quasi-periodic Wave Trains Within Global
    EUV ("EIT") Waves and Their Coronal Seismology Implications
Authors: Liu, Wei; Ofman, L.; Aschwanden, M. J.; Nitta, N.; Schrijver,
   C. J.; Title, A. M.; Tarbell, T. D.
Bibcode: 2012AAS...22051501L
Altcode:
  The nature of global EUV waves (so-called "EIT waves") has long
  been under debate because of instrumental limitations and projection
  effects when viewed on the solar disk. We present here high cadence
  SDO/AIA observations of global EUV waves occurring on the limb. We
  report newly discovered quasi-periodic wave trains located in the low
  corona within a broad, diffuse pulse of the global EUV wave ahead of
  the lateral CME front/flank. These waves coherently travel to large
  distances on the order of 1 solar radii with initial velocities up
  to 1400 km/s. They have dominant 1-3 minute periodicities that often
  match the X-ray pulsations of the accompanying flare, suggestive of
  a causal connection. In addition, recently discovered quasi-periodic
  fast propagating (QFP) waves of 1000-2000 km/s (Liu, Title, Zhao et
  al. 2011 ApJL) are found in the funnel of coronal loops rooted at the
  flare kernel. These waves are spatially confined within the CME bubble
  and rapidly disappear while approaching the CME front, suggestive
  of strong damping and/or dispersion. These observations provide new
  evidence of the fast-mode wave nature of the primary, fast component
  of a global EUV wave, running ahead of a secondary, slow component
  of CME-caused restructuring of the coronal magnetic field. We suggest
  that the two types of quasi-periodic waves are both integral parts of
  global coronal dynamics manifested as a CME/flare eruption, and they
  have important implications for global and local coronal seismology.

Title: Some Like it Hot: the Trajectory of Sungrazing Comet C/2011 W3
    (Lovejoy) in the Solar Neighborhood.
Authors: Saint-Hilaire, Pascal; Chodas, P. W.; Battams, K.; Tarbell,
   T. D.; Shine, R. A.; Liu, W.; Thompson, W. T.; Comet Lovejoy
   Collaboration Team
Bibcode: 2012AAS...22052107S
Altcode:
  Sungrazing comet Lovejoy (C/2011 W3) was a recent spectacle in the sky,
  observed from the ground and by a host of space-based instruments,
  including several solar observatories. It is the first sungrazing comet
  in recent memory to have survived perihelion (q 1.2 Rs). It is only
  the second sungrazer to have been observed in the Sun's low corona in
  the extreme ultra-violet (EUV), where a plethora of EUV observations
  were obtained by the SDO and STEREO spacecraft. Such an occurrence
  can be used to probe the solar corona and test our understanding
  of plasma and cometary physics. In this work, we use the best orbit
  elements currently available to plot the path of the comet's nucleus on
  solar EUV images from SDO/AIA, both STEREO/EUVIs, and yellow continuum
  (near the Na D lines) images from Hinode/SOT. We compare the predicted
  positions and timing of the comet's nucleus to the latter, while the
  SDO and STEREO EUV observations are used to estimate the distance at
  which the EUV tail appears behind the comet's nucleus.

Title: Magnetic Topology of a Naked Sunspot: Is It Really Naked?
Authors: Sainz Dalda, A.; Vargas Domínguez, S.; Tarbell, T. D.
Bibcode: 2012ApJ...746L..13S
Altcode: 2012arXiv1202.0591S
  The high spatial, temporal, and spectral resolution achieved by Hinode
  instruments gives much better understanding of the behavior of some
  elusive solar features, such as pores and naked sunspots. Their fast
  evolution and, in some cases, their small sizes have made their study
  difficult. The moving magnetic features (MMFs) have been studied during
  the last 40 years. They have been always associated with sunspots,
  especially with the penumbra. However, a recent observation of a naked
  sunspot (one with no penumbra) has shown MMF activity. The authors
  of this reported observation expressed their reservations about the
  explanation given to the bipolar MMF activity as an extension of the
  penumbral filaments into the moat. How can this type of MMF exist when
  a penumbra does not? In this Letter, we study the full magnetic and
  (horizontal) velocity topology of the same naked sunspot, showing how
  the existence of a magnetic field topology similar to that observed
  in sunspots can explain these MMFs, even when the intensity map of
  the naked sunspot does not show a penumbra.

Title: The Atmospheric Imaging Assembly (AIA) on the Solar Dynamics
    Observatory (SDO)
Authors: Lemen, James R.; Title, Alan M.; Akin, David J.; Boerner,
   Paul F.; Chou, Catherine; Drake, Jerry F.; Duncan, Dexter W.; Edwards,
   Christopher G.; Friedlaender, Frank M.; Heyman, Gary F.; Hurlburt, Neal
   E.; Katz, Noah L.; Kushner, Gary D.; Levay, Michael; Lindgren, Russell
   W.; Mathur, Dnyanesh P.; McFeaters, Edward L.; Mitchell, Sarah; Rehse,
   Roger A.; Schrijver, Carolus J.; Springer, Larry A.; Stern, Robert A.;
   Tarbell, Theodore D.; Wuelser, Jean-Pierre; Wolfson, C. Jacob; Yanari,
   Carl; Bookbinder, Jay A.; Cheimets, Peter N.; Caldwell, David; Deluca,
   Edward E.; Gates, Richard; Golub, Leon; Park, Sang; Podgorski, William
   A.; Bush, Rock I.; Scherrer, Philip H.; Gummin, Mark A.; Smith, Peter;
   Auker, Gary; Jerram, Paul; Pool, Peter; Soufli, Regina; Windt, David
   L.; Beardsley, Sarah; Clapp, Matthew; Lang, James; Waltham, Nicholas
Bibcode: 2012SoPh..275...17L
Altcode: 2011SoPh..tmp..106L; 2011SoPh..tmp..172L; 2011SoPh..tmp..241L;
   2011SoPh..tmp..115L
  The Atmospheric Imaging Assembly (AIA) provides multiple simultaneous
  high-resolution full-disk images of the corona and transition region
  up to 0.5 R<SUB>⊙</SUB> above the solar limb with 1.5-arcsec spatial
  resolution and 12-second temporal resolution. The AIA consists of four
  telescopes that employ normal-incidence, multilayer-coated optics to
  provide narrow-band imaging of seven extreme ultraviolet (EUV) band
  passes centered on specific lines: Fe XVIII (94 Å), Fe XVII, XXI
  (131 Å), Fe IX (171 Å), Fe XII, XXIV (193 Å), Fe XIV (211 Å),
  He II (304 Å), and Fe XVI (335 Å). One telescope observes C IV
  (near 1600 Å) and the nearby continuum (1700 Å) and has a filter
  that observes in the visible to enable coalignment with images from
  other telescopes. The temperature diagnostics of the EUV emissions
  cover the range from 6×10<SUP>4</SUP> K to 2×10<SUP>7</SUP> K. The
  AIA was launched as a part of NASA's Solar Dynamics Observatory (SDO)
  mission on 11 February 2010. AIA will advance our understanding of the
  mechanisms of solar variability and of how the Sun's energy is stored
  and released into the heliosphere and geospace.

Title: Initial Calibration of the Atmospheric Imaging Assembly (AIA)
    on the Solar Dynamics Observatory (SDO)
Authors: Boerner, Paul; Edwards, Christopher; Lemen, James; Rausch,
   Adam; Schrijver, Carolus; Shine, Richard; Shing, Lawrence; Stern,
   Robert; Tarbell, Theodore; Title, Alan; Wolfson, C. Jacob; Soufli,
   Regina; Spiller, Eberhard; Gullikson, Eric; McKenzie, David; Windt,
   David; Golub, Leon; Podgorski, William; Testa, Paola; Weber, Mark
Bibcode: 2012SoPh..275...41B
Altcode:
  The Atmospheric Imaging Assembly (AIA) instrument onboard the Solar
  Dynamics Observatory (SDO) is an array of four normal-incidence
  reflecting telescopes that image the Sun in ten EUV and UV wavelength
  channels. We present the initial photometric calibration of AIA,
  based on preflight measurements of the response of the telescope
  components. The estimated accuracy is of order 25%, which is consistent
  with the results of comparisons with full-disk irradiance measurements
  and spectral models. We also describe the characterization of the
  instrument performance, including image resolution, alignment,
  camera-system gain, flat-fielding, and data compression.

Title: Design and Ground Calibration of the Helioseismic and Magnetic
    Imager (HMI) Instrument on the Solar Dynamics Observatory (SDO)
Authors: Schou, J.; Scherrer, P. H.; Bush, R. I.; Wachter, R.;
   Couvidat, S.; Rabello-Soares, M. C.; Bogart, R. S.; Hoeksema, J. T.;
   Liu, Y.; Duvall, T. L.; Akin, D. J.; Allard, B. A.; Miles, J. W.;
   Rairden, R.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Wolfson,
   C. J.; Elmore, D. F.; Norton, A. A.; Tomczyk, S.
Bibcode: 2012SoPh..275..229S
Altcode:
  The Helioseismic and Magnetic Imager (HMI) investigation (Solar
  Phys. doi:10.1007/s11207-011-9834-2, 2011) will study the solar
  interior using helioseismic techniques as well as the magnetic field
  near the solar surface. The HMI instrument is part of the Solar
  Dynamics Observatory (SDO) that was launched on 11 February 2010. The
  instrument is designed to measure the Doppler shift, intensity, and
  vector magnetic field at the solar photosphere using the 6173 Å Fe I
  absorption line. The instrument consists of a front-window filter, a
  telescope, a set of waveplates for polarimetry, an image-stabilization
  system, a blocking filter, a five-stage Lyot filter with one tunable
  element, two wide-field tunable Michelson interferometers, a pair
  of 4096<SUP>2</SUP> pixel cameras with independent shutters, and
  associated electronics. Each camera takes a full-disk image roughly
  every 3.75 seconds giving an overall cadence of 45 seconds for the
  Doppler, intensity, and line-of-sight magnetic-field measurements
  and a slower cadence for the full vector magnetic field. This article
  describes the design of the HMI instrument and provides an overview of
  the pre-launch calibration efforts. Overviews of the investigation,
  details of the calibrations, data handling, and the science analysis
  are provided in accompanying articles.

Title: The Helioseismic and Magnetic Imager (HMI) Investigation for
    the Solar Dynamics Observatory (SDO)
Authors: Scherrer, P. H.; Schou, J.; Bush, R. I.; Kosovichev, A. G.;
   Bogart, R. S.; Hoeksema, J. T.; Liu, Y.; Duvall, T. L.; Zhao, J.;
   Title, A. M.; Schrijver, C. J.; Tarbell, T. D.; Tomczyk, S.
Bibcode: 2012SoPh..275..207S
Altcode:
  The Helioseismic and Magnetic Imager (HMI) instrument and investigation
  as a part of the NASA Solar Dynamics Observatory (SDO) is designed
  to study convection-zone dynamics and the solar dynamo, the origin
  and evolution of sunspots, active regions, and complexes of activity,
  the sources and drivers of solar magnetic activity and disturbances,
  links between the internal processes and dynamics of the corona and
  heliosphere, and precursors of solar disturbances for space-weather
  forecasts. A brief overview of the instrument, investigation objectives,
  and standard data products is presented.

Title: Spectropolarimetric Comparison Between SDO/HMI and
    Hinode-SOT/SP Through THEMIS/MTR
Authors: Sainz Dalda, A.; Lopez Ariste, A.; Gelly, B.; Tarbell, T. D.;
   Centeno, R.; DeRosa, M. L.; Hoeksema, J. T.
Bibcode: 2011AGUFMSH31A1986S
Altcode:
  In the golden age of solar spacecraft observatories, the use of similar
  instruments observing same targets offers us the possibility to get
  more accurate information of the physical processes taking place on
  them. We present a comparison between the vector magnetic field and
  thermodynamic quantities obtained by three different spectropolarimetric
  instruments. We have used the simultaneous multi-wavelength capabilities
  of THEMIS/MTR as bridge between the observations at Fe I 6173 Å
  provided by SDO/HMI and at Fe I 6301 &amp; 6302 Å by Hinode-SOT/SP
  observations. The official inversion codes for these instruments (PCA
  based-on, VFISV and MERLIN respectively) have been used with the data
  properly arranged for them. Therefore, we compare the final products
  usually offered to the community, i.e. after the inversion, using
  different codes and these different wavelengths. The cross-calibration
  of these products shall allow us to go forward from one instrument
  result to other one in an easy, convenient way.

Title: Direct Imaging of Quasi-periodic Fast Propagating Waves of
    ~2000 km s<SUP>-1</SUP> in the Low Solar Corona by the Solar Dynamics
    Observatory Atmospheric Imaging Assembly
Authors: Liu, Wei; Title, Alan M.; Zhao, Junwei; Ofman, Leon;
   Schrijver, Carolus J.; Aschwanden, Markus J.; De Pontieu, Bart;
   Tarbell, Theodore D.
Bibcode: 2011ApJ...736L..13L
Altcode: 2011arXiv1106.3150L
  Quasi-periodic propagating fast mode magnetosonic waves in the solar
  corona were difficult to observe in the past due to relatively low
  instrument cadences. We report here evidence of such waves directly
  imaged in EUV by the new Atmospheric Imaging Assembly instrument
  on board the Solar Dynamics Observatory. In the 2010 August 1 C3.2
  flare/coronal mass ejection event, we find arc-shaped wave trains of
  1%-5% intensity variations (lifetime ~200 s) that emanate near the
  flare kernel and propagate outward up to ~400 Mm along a funnel of
  coronal loops. Sinusoidal fits to a typical wave train indicate a phase
  velocity of 2200 ± 130 km s<SUP>-1</SUP>. Similar waves propagating
  in opposite directions are observed in closed loops between two flare
  ribbons. In the k-ω diagram of the Fourier wave power, we find a
  bright ridge that represents the dispersion relation and can be well
  fitted with a straight line passing through the origin. This k-ω
  ridge shows a broad frequency distribution with power peaks at 5.5,
  14.5, and 25.1 mHz. The strongest signal at 5.5 mHz (period 181 s)
  temporally coincides with quasi-periodic pulsations of the flare,
  suggesting a common origin. The instantaneous wave energy flux
  of (0.1-2.6) × 10<SUP>7</SUP> erg cm<SUP>-2</SUP> s<SUP>-1</SUP>
  estimated at the coronal base is comparable to the steady-state heating
  requirement of active region loops.

Title: SDO/AIA Observations of a Global EUV Disturbance Traveling
into a Coronal Cavity and Its Subsequent Oscillations: New Evidence
    of Fast Mode MHD Waves
Authors: Liu, Wei; Aschwanden, M. J.; Ofman, L.; Nitta, N. V.; Tarbell,
   T. D.
Bibcode: 2011SPD....42.0906L
Altcode: 2011BAAS..43S.0906L
  We report new SDO/AIA observations of a global EUV disturbance
  that propagates at 600 km/s and sweeps through a coronal cavity,
  instigating its bodily transverse oscillations. The high temporal
  resolution and large FOV of AIA allow us to clearly see, for the first
  time, the timing coincidence between the onsets of the oscillations
  and the arrival of the disturbance at increasing distances covering
  300 Mm in the neighborhood of the cavity. There is a time delay of
  the oscillations from the near side to the far side of the cavity,
  which is consistent with the travel time of the global perturbation. In
  addition, we find a fine structure consisting of evenly spaced pulses
  of periods 100-120 s within the global disturbance. In contrast, the
  CME loop expansion falls behind the global disturbance at a smaller
  velocity of 200 km/s. These observations suggests that this global
  disturbance is a real fast mode MHD wave that continues propagating
  into the cavity, rather than an apparent wave caused by CME expulsion
  that is not expected to penetrate through a topological separatrix,
  including the flux rope cavity boundary here. The cavity and its
  hosted prominence have oscillation amplitudes of 20 km/s and periods
  of 20-30 minutes. Such unusually long periods, compared with a few
  minutes commonly observed in coronal loops, likely reflect kink mode
  oscillations of the long cavity flux rope of a large length (a fraction
  of the solar radius).

Title: The Interface Region Imaging Spectrograph (IRIS) NASA SMEX
Authors: Lemen, James; Title, A.; De Pontieu, B.; Schrijver, C.;
   Tarbell, T.; Wuelser, J.; Golub, L.; Kankelborg, C.
Bibcode: 2011SPD....42.1512L
Altcode: 2011BAAS..43S.1512L
  The solar chromosphere and transition region (TR) is highly structured,
  dynamic, and intimately connected to the corona. It requires more
  than ten times the energy required to heat the corona, and yet it
  has received far less interest because of the complexity of the
  required observational and analytical tools. In the TR the density
  drops by six orders of magnitude and the temperature increases by
  three orders of magnitude. Hinode observations reveal the importance
  the magnetic field has on this region of the solar atmosphere that
  acts as the interface between the photosphere and the corona. The
  Interface Region Imaging Spectrograph (IRIS) was selected for a NASA
  SMEX mission in 2009 and is scheduled to launch in December 2012. IRIS
  addresses critical questions in order to understand the flow of energy
  and mass through the chromosphere and TR, namely: (1) Which types of
  non-thermal energy dominate in the chromosphere and beyond? (2) How
  does the chromosphere regulate mass and energy supply to the corona
  and heliosphere? (3) How do magnetic flux and matter rise through the
  lower atmosphere, and what roles dos flux emergence play in flares and
  mass ejections? These questions are addressed with a high-resolution
  imaging spectrometer that observes Near- and Far-VU emissions that
  are formed at temperatures between 5,000K and 1.5 x 10<SUP>6</SUP>
  K. IRIS has a field-of-view of 120 arcsec, a spatial resolution
  of 0.4 arcsec, and velocity resolution of 0.5 km/s. Members of the
  IRIS investigation team are developing advanced radiative MHD codes
  to facilitate comparison with and interpretation of observations. We
  present the status of the IRIS observatory development, which completed
  its Critical Design Review in December 2010.

Title: Spectropolarimetric Study of Sea-serpent Penumbral Filaments
    and a Naked Sunspot
Authors: Sainz Dalda, Alberto; Tarbell, T.; Title, A.; Vargas
   Dominguez, S.; Bellot Rubio, L. R.
Bibcode: 2011SPD....42.0303S
Altcode: 2011BAAS..43S.0303S
  We present a spectropolarimetric study of the sea-serpent penumbral
  filaments in AR NOAA 10944 and of a naked sunspot (i.e. a sunspot-like
  feature without penumbra) in AR NOAA 10977. Both active regions were
  observed by Hinode-SOT/SP in the photospheric lines Fe I 6301 &amp;
  6302 [[Unable to Display Character: &amp;#506]]. The high spatial and
  temporal resolution combined with the high polarimetric sensitivity
  of these observations enables us to get a better understanding of the
  dynamics of the penumbra and the moving magnetic feature (herafter MMF)
  activity in and around both traditional and naked sunspots. Our results
  show how the temporal evolution of the sea-serpent filaments fits
  very well with the thin-tube flux model for the penumbra presented by
  Schlichenmaier (2003). In addition, the spectropolarmetric analysis of
  the naked sunspot addresses the issue posed by Zuccarello et al. (2009)
  about the existence of bipolar MMFs around naked sunspots even when
  they cannot be explained as an extension of the penumbral filaments.

Title: Helioseismic Studies With Multi-wavelength Data From HMI And
    AIA Onboard SDO
Authors: Hill, Frank; Jain, K.; Tripathy, S.; Kholikov, S.; Gonzalez
   Hernandez, I.; Leibacher, J.; Howe, R.; Baudin, F.; Carlsson, M.;
   Chaplin, W.; Tarbell, T.
Bibcode: 2011SPD....42.2111H
Altcode: 2011BAAS..43S.2111H
  The successful launch of the Solar Dynamics Observatory (SDO) in
  February 2010 opens important, new possibilities for helioseismic
  exploration of the solar interior and atmosphere using multi-wavelength
  observations from multiple instruments. In order to better understand
  the solar interior and atmosphere, as well as the physics of the
  helioseismic modes and waves themselves, we exploit the potential of
  the Atmospheric Imaging Assembly (AIA) 1600 and 1700 Angstrom continuum
  measurements and the contemporaneous Helioseismic and Magnetic Imager
  (HMI) Fe I 6173.3 Angstrom velocity and intensity observations. Standard
  techniques of helioseismology e.g Sun-as-a-star, spherical harmonic
  analysis, ring diagrams, and time- distance analysis are applied to
  obtain acoustic mode parameters and other characteristics. Here we
  present our preliminary results, and interpret these in the context
  of the differences in the heights of formation of the lines.

Title: Direct Imaging by SDO/AIA of Quasi-periodic Propagating Fast
    Mode Magnetosonic Waves of  2000 km/s in the Solar Corona
Authors: Liu, Wei; Title, A. M.; Zhao, J.; Ofman, L.; Schrijver,
   C. J.; Aschwanden, M. J.; De Pontieu, B.; Tarbell, T. D.
Bibcode: 2011SPD....42.2114L
Altcode: 2011BAAS..43S.2114L
  Quasi-periodic, propagating fast mode magnetosonic waves in the
  corona were difficult to observe in the past due to relatively low
  instrument cadences. We report here unprecedented evidence of such
  waves directly imaged in EUV by the new SDO/AIA instrument. In the 2010
  August 1 C3.2 flare/CME event, we find arc-shaped wave trains of 1-5%
  intensity variations emanating near the flare kernel and propagating
  outward along a funnel of coronal loops. Sinusoidal fits to a typical
  wave train indicate a phase velocity of 2350 +/- 210 km/s. Similar
  waves propagating in opposite directions are observed in closed loops
  between two flare ribbons. In the k-omega diagram of the Fourier wave
  power, we find a bright ridge that represents the dispersion relation
  and can be well fitted with a straight line passing through the
  origin, giving an equal phase and group velocity of 1630 +/- 760 km/s
  averaged over the event. This k-omega ridge shows a broad frequency
  distribution with prominent power at four non-harmonic frequencies,
  5.5, 14.5, 25.1, and 37.9 mHz, among which the 14.5 mHz (period:
  69 s) signal is the strongest. The signal at 5.5 mHz (period: 181 s,
  same as chromospheric 3-minute oscillations) temporally coincides with
  flare pulsations, suggesting a common origin of possibly quasi-periodic
  magnetic reconnection. The instantaneous wave energy flux of (0.1-2.6)e7
  ergs/cm<SUP>2</SUP>/s estimated at the coronal base is comparable to
  the steady-state heating requirement of active region loops.

Title: Monitoring Image Alignments and Flat Fields for AIA/SDO
    Data Images
Authors: Shine, Richard A.; Wolfson, C.; Boerner, P. F.; Tarbell,
   T. D.; Nightingale, R. W.
Bibcode: 2011SPD....42.2126S
Altcode: 2011BAAS..43S.2126S
  The images from the 4 telescopes on the Atmospheric Imaging Assembly
  (AIA) on board the NASA Solar Dynamics Observatory (SDO) have different
  offsets (from sun center), plate scales, and absolute rotations that
  can be measured and corrected for accurate alignment. The most variable
  of these is the offsets presumably due to small thermal flexings of
  the telescopes. Here we describe the techniques used to make these
  measurements and show how the image alignments vary with time. Weekly
  measurements are made as part of the data monitoring that capture much
  of the drift in the geometric corrections but shorter time variations
  of typically a pixel also exist in the offsets. Angles and scales
  have much better short term stability. We hope to eventually capture
  these variations for the mission or at least provide software for
  end users. <P />We also describe progress made in determining flat
  fields for the 10 wavebands and show how these have been varying over
  the mission to date. <P />This work was supported by NASA under the
  SDO/AIA contract NNG04EA00C.

Title: Magneto-thermal convection in solar prominences
Authors: Berger, Thomas; Testa, Paola; Hillier, Andrew; Boerner, Paul;
   Low, Boon Chye; Shibata, Kazunari; Schrijver, Carolus; Tarbell, Ted;
   Title, Alan
Bibcode: 2011Natur.472..197B
Altcode:
  Coronal cavities are large low-density regions formed by
  hemispheric-scale magnetic flux ropes suspended in the Sun's outer
  atmosphere. They evolve over time, eventually erupting as the dark
  cores of coronal mass ejections. Although coronal mass ejections are
  common and can significantly affect planetary magnetospheres, the
  mechanisms by which cavities evolve to an eruptive state remain poorly
  understood. Recent optical observations of high-latitude `polar crown'
  prominences within coronal cavities reveal dark, low-density `bubbles'
  that undergo Rayleigh-Taylor instabilities to form dark plumes rising
  into overlying coronal cavities. These observations offered a possible
  mechanism for coronal cavity evolution, although the nature of the
  bubbles, particularly their buoyancy, was hitherto unclear. Here we
  report simultaneous optical and extreme-ultraviolet observations of
  polar crown prominences that show that these bubbles contain plasma at
  temperatures in the range (2.5-12)×10<SUP>5</SUP> kelvin, which is
  25-120 times hotter than the overlying prominence. This identifies a
  source of the buoyancy, and suggests that the coronal cavity-prominence
  system supports a novel form of magneto-thermal convection in the solar
  atmosphere, challenging current hydromagnetic concepts of prominences
  and their relation to coronal cavities.

Title: Chromospheric Jet and Growing "Loop" Observed by Hinode: New
    Evidence of Fan-spine Magnetic Topology Resulting from Flux Emergence
Authors: Liu, Wei; Berger, Thomas E.; Title, Alan M.; Tarbell,
   Theodore D.; Low, B. C.
Bibcode: 2011ApJ...728..103L
Altcode: 2010arXiv1012.1897L
  We present observations of a chromospheric jet and growing "loop" system
  that show new evidence of a fan-spine topology resulting from magnetic
  flux emergence. This event, occurring in an equatorial coronal hole on
  2007 February 9, was observed by the Hinode Solar Optical Telescope in
  the Ca II H line in unprecedented detail. The predecessor of the jet is
  a bundle of fine material threads that extend above the chromosphere and
  appear to rotate about the bundle axis at ~50 km s<SUP>-1</SUP> (period
  lsim200 s). These rotations or transverse oscillations propagate upward
  at velocities up to 786 km s<SUP>-1</SUP>. The bundle first slowly and
  then rapidly swings up, with the transition occurring at the onset of an
  A4.9 flare. A loop expands simultaneously in these two phases (velocity:
  16-135 km s<SUP>-1</SUP>). Near the peak of the flare, the loop appears
  to rupture; simultaneous upward ejecta and mass downflows faster than
  free-fall appear in one of the loop legs. The material bundle then
  swings back in a whip-like manner and develops into a collimated jet,
  which is orientated along the inferred open-field lines with transverse
  oscillations continuing at slower rates. Some material falls back along
  smooth streamlines, showing no more oscillations. At low altitudes, the
  streamlines bifurcate at presumably a magnetic null point and bypass
  an inferred dome, depicting an inverted-Y geometry. These streamlines
  closely match in space the late Ca II H loop and X-ray flare loop. These
  observations are consistent with the model that flux emergence in an
  open-field region leads to magnetic reconnection, forming a jet and
  fan-spine topology. We propose that the material bundle and collimated
  jet represent the outer spine in quasi-static and eruptive stages,
  respectively, and the growing loop is a two-dimensional projection of
  the three-dimensional fan surface.

Title: Early Results from the Atmospheric Imaging Assembly (AIA)
    on the Solar Dynamics Observatory (SDO)
Authors: Tarbell, Theodore D.; AIA Team
Bibcode: 2011AAS...21715509T
Altcode: 2011BAAS...4315509T
  SDO was launched on February 11, 2010, and first light was in late
  March. AIA provides multiple simultaneous high-resolution full-disk
  images of the corona and transition region up to 0.5 R above the solar
  limb with 1.5" spatial resolution (0.6" pixels) and 10 second temporal
  resolution. AIA consists of four telescopes that employ normal incidence
  multilayer coated optics to provide narrow band imaging of seven EUV
  band-passes centered on specific lines: Fe XVIII (94 A), Fe VIII, XX,
  XXIII (131 A), Fe IX (171 A), Fe XII, XXIV (193 A), Fe XIV (211 A), He
  II (304 A), and Fe XVI (335 A). One telescope observes C IV (1600 A)
  and the nearby continuum (1700 A), and a filter that observes in the
  visible enables coalignment with images from other telescopes. The
  temperature diagnostics of the EUV emissions covers the range from
  0.06M °K to 20M °K. Since early April, these images have been taken
  nearly continuously, usually with a cadence of 12 seconds. Although
  solar activity has only been increasing slowly in this cycle, there
  have been a large number of filament ejections that interact with
  large regions over the solar surface. In addition, because of the rapid
  cadence of images, a number of new wave phenomena have been discovered
  associated both with small flares and the interaction of expanding
  magnetic structures with pre-existing structures. Movies illustrating
  some of these events will be shown. <P />AIA is supported by NASA (GSFC)
  contract NNG04EA00C at the Lockheed Martin Advanced Technology Center.

Title: The Origins of Hot Plasma in the Solar Corona
Authors: De Pontieu, B.; McIntosh, S. W.; Carlsson, M.; Hansteen,
   V. H.; Tarbell, T. D.; Boerner, P.; Martinez-Sykora, J.; Schrijver,
   C. J.; Title, A. M.
Bibcode: 2011Sci...331...55D
Altcode:
  The Sun's outer atmosphere, or corona, is heated to millions of degrees,
  considerably hotter than its surface or photosphere. Explanations for
  this enigma typically invoke the deposition in the corona of nonthermal
  energy generated by magnetoconvection. However, the coronal heating
  mechanism remains unknown. We used observations from the Solar Dynamics
  Observatory and the Hinode solar physics mission to reveal a ubiquitous
  coronal mass supply in which chromospheric plasma in fountainlike jets
  or spicules is accelerated upward into the corona, with much of the
  plasma heated to temperatures between ~0.02 and 0.1 million kelvin (MK)
  and a small but sufficient fraction to temperatures above 1 MK. These
  observations provide constraints on the coronal heating mechanism(s)
  and highlight the importance of the interface region between photosphere
  and corona.

Title: Flat Fielding and Image Alignments for AIA/SDO Data Images
Authors: Shine, R. A.; Nightingale, R. W.; Boerner, P.; Tarbell,
   T. D.; Wolfson, C. J.
Bibcode: 2010AGUFMSH23C1872S
Altcode:
  The Atmospheric Imaging Assembly (AIA) on the NASA Solar Dynamics
  Observatory (SDO) takes 4096 by 4096 CCD images of the sun in 10
  wavelengths utilizing 4 telescopes and each wavelength channel requires
  a flat field that is applied shortly after receipt of the data on the
  ground. Although some useful information about the CCD's was obtained
  pre-launch, most of the flat field computation must be done with solar
  images taken in orbit. Raw flat field images are collected as out of
  focus images at 14 offsets using PZT adjustments on each telescope
  and then each wavelength group is processed together using the Kuhn,
  Lin, and Loranz (1991) flat field algorithm. However, the PZT motions
  are restricted to about 14 arc sec limiting the measurement of large
  scale variations. Hence larger offsets are also used by adjusting
  the space craft pointing. All of these suffer from changes in the
  solar image between exposures (especially the larger offsets), low
  counts in some channels, and reflections in the UV channels. These
  make direct use of the flats unfeasible and instead we process them to
  compute 6 separable effects: 1) differences in the CCD quad gains and
  inner row/column effects, 2) a repeating pattern across the CCD from
  the manufacturing process (dubbed "tire tracks"), 3) a grid pattern
  in the extreme ultraviolet wavelengths from the back filter, 4)
  blemishes (some are translucent and some are treated as bad pixels),
  5) large scale vignetting, and 6) all other variations. The last
  category includes all remaining flat field effects after the others
  are removed. This has not been done well for any of the wavelengths
  yet. These effects will be described and illustrated, as will the
  before and after images resulting from applying the processed flat
  fields. We also describe techniques for fitting the solar limb to
  accurately determine image centers and radii. This is not a trivial
  problem for the extreme ultraviolet images but is required to align
  images, determine relative plate scales, and monitor pointing variations
  related to thermal changes. All channels except the He II 304A can be
  now be routinely measured with an rms error of typically less than 0.2
  arc sec. This allows us to easily see the radius variations during the
  24 hour orbit for example. The computer code requires about 3 seconds
  (single threaded) for each measurement. This work was supported by
  NASA under the SDO/AIA contract NNG04EA00C.

Title: Coordinated observations of solar prominences with Hinode/SOT
    and SDO/AIA
Authors: Berger, T. E.; Tarbell, T. D.; Schrijver, C. J.; Title,
   A. M.; Boerner, P.; Shine, R. A.
Bibcode: 2010AGUFMSH21C..04B
Altcode:
  We show the first detailed study of a solar quiescent prominence
  using simultaneous observations from the Hinode/SOT and SDO/AIA
  instruments. The prominence studied is a polar crown prominence
  located at the base of a large coronal cavity on the NW solar limb on
  22-June-2010. Hinode observed the prominence for 2.75 hours running
  the HOP 73 prominence observation program to acquire Ca II H-line
  filtergrams and H-alpha doppler observations at a 20-second cadence. SOT
  observations in Ca II H-line and H-alpha spectral lines reveal the
  common dynamics of filamentary downflows and large-scale oscillations
  of the prominence body. In addition a dark cavity is observed to
  rise into the prominence and stagnate before going unstable to form
  Rayleigh-Taylor plume upflows. AIA observations in the 304, 171, 193,
  and 211 channels with 14 second cadence reveal that both the cavity
  and the plume upflows are bright in these hotter passbands. Filter
  ratio measurements as well as preliminary EM estimates imply that
  the cavity and plume plasma temperature is at least 10^6 K. Plasma at
  this temperature has never been detected or theorized in a confined
  configuration in the lower chromosphere below a prominence. Assuming
  an electron number density of 3e09 cm-3, the balance between thermal
  pressure in the cavity and magnetic pressure in the overlying prominence
  implies a magnetic flux density of order 10 gauss, in line with earlier
  measurements of prominence magnetic fields. However the cavity likely
  contains a significant magnetic energy density of its own implying that
  the prominence magnetic fields may need to be significantly higher to
  balance the cavity buoyancy. The existence of 10^6 K plasma confined
  below a quiescent prominence and the subsequent onset of buoyancy
  instabilities present new challenges to theories of prominence and
  coronal cavity formation and suggest new avenues for supply of mass
  and magnetic flux to the associated coronal cavity systems that make
  up the bulk of CMEs. Hinode/SOT Ca II H-line image overlain on SDO/AIA
  304A image of a quiescent solar prominence.

Title: First results for the Solar Ultraviolet Magnetograph
    Investigation (SUMI)
Authors: Moore, R. L.; Cirtain, J. W.; West, E.; Kobayashi, K.;
   Robinson, B.; Winebarger, A. R.; Tarbell, T. D.; de Pontieu, B.;
   McIntosh, S. W.
Bibcode: 2010AGUFMSH11B1655M
Altcode:
  On July 31, 2010 SUMI was launched to 286km above the White
  Sands Missile Range to observe active region 11092. SUMI is a
  spectro-polarimeter capable of measuring the spectrum for Mg II h &amp;
  k at 280 nm and C IV at 155 nm. Simultaneous observations with Hinode
  and SDO provide total coverage of the region from the photosphere into
  the corona, a very unique and original data set. We will present the
  initial results from this first flight of the experiment and demonstrate
  the utility of further observations by SUMI.

Title: First SDO/AIA Observations of Global Coronal EUV "Waves":
    Multiple Components and "Ripples"
Authors: Liu, W.; Nitta, N. V.; Schrijver, C. J.; Title, A. M.;
   Tarbell, T. D.
Bibcode: 2010AGUFMSH13A..07L
Altcode:
  Global coronal EUV disturbances (so-called "EIT waves") are useful
  diagnostics for physical conditions on the Sun. Major drawbacks that
  hindered our understanding of this phenomenon were previous instruments'
  single view point, low cadence (e.g., 12 minutes of EIT), and limited
  wavelength coverage. The Atmospheric Imaging Assembly (AIA) on board
  the Solar Dynamics Observatory (SDO) observes the full-sun corona
  at 10 EUV and UV wavelengths, covering a wide range of temperatures,
  with high resolution (1.4") and cadence (up to 12 s). It thus offers a
  great chance to end the decade long debate on the nature of global EUV
  "waves". We present here the first AIA observations of such phenomenon
  on 2010 April 8 revealed in unprecedented detail and discuss their
  physical implications. The disturbance exhibits two components: one
  weak, diffuse pulse superimposed by multiple strong, sharp fronts,
  which again have slow and fast components. The disturbance originates
  in front of erupting coronal loops and the slow sharp front undergoes
  acceleration, both implying the disturbance being driven by the
  coronal mass ejection (CME). Even at a 20 s cadence, the diffuse pulse
  propagates at a surprisingly constant velocity of ~200 km/s, weakly
  dependent on direction. The fast sharp front overtakes the slow front,
  producing multiple "ripples" and steepening of the local pulse, and both
  fronts propagate independently afterwards. These resemble the nature
  of real waves. Unexpectedly, the amplitude and FWHM of the diffuse
  pulse decreases linearly with distance. The diffuse pulse appears as
  emission enhancement at hotter 193 Å but reduction at cooler 171 Å,
  suggestive of heating, while the sharp fronts appear as enhancement at
  both wavelengths, indicating density increase. As evidence for both
  wave and non-wave models of "EIT waves" has been found, we suggest
  that a hybrid model combining both mechanisms (e.g., Cohen et al. 2010)
  may best explaine the data. In addition to the global EUV disturbance,
  we found fast (600-1100 km/s) features repeated at 100 s intervals
  as tentative evidence of fast mode MHD waves. Discoveries of the fast
  features, multiple ripples, and two-component fronts were made possible
  for the first time thanks to AIA's high cadences and sensitivities.

Title: The role of the chromosphere in filling the corona with hot
    plasma (Invited)
Authors: de Pontieu, B.; McIntosh, S. W.; Carlsson, M.; Hansteen,
   V. H.; Tarbell, T. D.; Boerner, P.; Martinez-Sykora, J.; Schrijver,
   C. J.; Title, A. M.
Bibcode: 2010AGUFMSH21C..03D
Altcode:
  We use coordinated observations from the Solar Dynamics Observatory
  (SDO), Hinode and the Swedish Solar Telescope (SST) to show how
  plasma is heated to coronal temperatures from its source in the
  chromosphere. Our observations reveal a ubiquitous mass supply
  for the solar corona in which chromospheric plasma is accelerated
  upward into the corona with much of the plasma heated to transition
  region temperatures, and a small, but significant fraction heated
  to temperatures in excess of 1 million K. Our observations show,
  for the first time, how chromospheric spicules, fountain-like jets
  that have long been considered potential candidates for coronal
  heating, are directly associated with heating of plasma to coronal
  temperatures. These results provide strong physical constraints on
  the mechanism(s) responsible for coronal heating and do not seem
  compatible with current models. The association with chromospheric
  spicules highlights the importance of the interface region between
  the photosphere and corona to gain a full understanding of the coronal
  heating problem.

Title: Observation of Plasma Instabilities in Quiescent Prominences
Authors: Ryutova, M.; Berger, T.; Frank, Z.; Tarbell, T.; Title, A.
Bibcode: 2010SoPh..267...75R
Altcode: 2010SoPh..tmp..170R
  We study dynamics of quiescent prominences using several data sets taken
  with the Solar Optical Telescope (SOT) on Hinode. We find a number of
  processes occurring at different stages of prominence evolution that
  are common for all of our chosen cases and, having universal character,
  can be related to fundamental plasma instabilities. We combine the
  observational evidence and theory to identify these instabilities. Here
  we discuss three examples: i) prominence cavity formation and its
  evolution, associated with a screw-pinch instability; ii) development
  of a regular series of plumes and spikes typical to the Rayleigh -
  Taylor (RT) instability; and iii) the appearance of growing ripples at
  the prominence/corona interface, often followed by a sudden collimated
  mass upflow, attributed to the Kelvin - Helmholtz (KH) instability. The
  conditions for transition from a linear (rippling mode) to nonlinear
  stage of the KH instability, known to have an explosive character,
  are specified. Given excellent Hinode data, all three aspects of
  prominence dynamics allow quantitative analysis.

Title: First SDO AIA Observations of a Global Coronal EUV "Wave":
    Multiple Components and "Ripples"
Authors: Liu, Wei; Nitta, Nariaki V.; Schrijver, Carolus J.; Title,
   Alan M.; Tarbell, Theodore D.
Bibcode: 2010ApJ...723L..53L
Altcode: 2012arXiv1201.0815L
  We present the first Solar Dynamics Observatory Atmospheric Imaging
  Assembly (AIA) observations of a global coronal EUV disturbance
  (so-called "EIT wave") revealed in unprecedented detail. The disturbance
  observed on 2010 April 8 exhibits two components: one diffuse pulse
  superimposed, on which are multiple sharp fronts that have slow and
  fast components. The disturbance originates in front of erupting coronal
  loops and some sharp fronts undergo accelerations, both effects implying
  that the disturbance is driven by a coronal mass ejection. The diffuse
  pulse, propagating at a uniform velocity of 204-238 km s<SUP>-1</SUP>
  with very little angular dependence within its extent in the south,
  maintains its coherence and stable profile for ~30 minutes. Its arrival
  at increasing distances coincides with the onsets of loop expansions and
  the slow sharp front. The fast sharp front overtakes the slow front,
  producing multiple "ripples" and steepening the local pulse, and both
  fronts propagate independently afterward. This behavior resembles
  the nature of real waves. Unexpectedly, the amplitude and FWHM of
  the diffuse pulse decrease linearly with distance. A hybrid model,
  combining both wave and non-wave components, can explain many, but
  not all, of the observations. Discoveries of the two-component fronts
  and multiple ripples were made possible for the first time thanks to
  AIA's high cadences (&lt;=20 s) and high signal-to-noise ratio.

Title: Hinode Observation of Photospheric Magnetic Activities
    Triggering X-ray Microflares Around a Well-developed Sunspot
Authors: Kano, R.; Shimizu, T.; Tarbell, T. D.
Bibcode: 2010ApJ...720.1136K
Altcode:
  Microflares, which are small energetic events in the solar corona, are
  an example of dynamical phenomena suitable for understanding energy
  release processes in the solar corona. We identified 55 microflares
  around a well-developed sunspot surrounded by a moat with high-cadence
  X-ray images from the Hinode X-ray Telescope, and searched for their
  photospheric counterparts in line-of-sight magnetograms taken with the
  Hinode Solar Optical Telescope. We found opposite magnetic polarities
  encountering each other around the footpoints of 28 microflares,
  while we could not find such encounters around the footpoints of the
  other 27 microflares. Emerging magnetic fluxes in the moat were the
  dominant origin causing the encounters of opposite polarities (21 of
  28 events). Unipolar moving magnetic features (MMFs) with negative
  polarities the same as the sunspot definitely caused the encounters of
  opposite polarities for five microflares. The decrease of magnetic flux,
  i.e., magnetic flux cancellation, was confirmed at the encountering site
  in typical examples of microflares. Microflares were not isotropically
  distributed around the spot; the microflares with emerging magnetic
  fluxes (EMFs) were observed in the direction where magnetic islands
  with the same polarity as the spot were located at the outer boundary
  of the moat, while the microflares with negative MMFs were observed
  in the direction where magnetic islands with polarity opposite to the
  spot were located at the outer boundary of the moat. We also found that
  EMFs in the moat had a unique orientation in which those with the same
  polarity as the spot is closer to the spot than the other one that had
  the opposite polarity to the spot. These observational results lead
  to two magnetic configurations including magnetic reconnection for
  triggering energy release at least in half of the microflares around
  the spot, and suggest that the global magnetic structures around the
  spot strongly affect what kinds of polarity encounters are formed in
  the sunspot moat.

Title: Emergence of Helical Flux and the Formation of an Active
    Region Filament Channel
Authors: Lites, B. W.; Kubo, M.; Berger, T.; Frank, Z.; Shine, R.;
   Tarbell, T.; Title, A.; Okamoto, T. J.; Otsuji, K.
Bibcode: 2010ApJ...718..474L
Altcode:
  We present comprehensive observations of the formation and evolution
  of a filament channel within NOAA Active Region (AR) 10978 from
  Hinode/Solar Optical Telescope and TRACE. We employ sequences
  of Hinode spectro-polarimeter maps of the AR, accompanying Hinode
  Narrowband Filter Instrument magnetograms in the Na I D1 line, Hinode
  Broadband Filter Instrument filtergrams in the Ca II H line and G-band,
  Hinode X-ray telescope X-ray images, and TRACE Fe IX 171 Å image
  sequences. The development of the channel resembles qualitatively
  that presented by Okamoto et al. in that many indicators point to
  the emergence of a pre-existing sub-surface magnetic flux rope. The
  consolidation of the filament channel into a coherent structure takes
  place rapidly during the course of a few hours, and the filament form
  then gradually shrinks in width over the following two days. Particular
  to this filament channel is the observation of a segment along its
  length of horizontal, weak (500 G) flux that, unlike the rest of the
  filament channel, is not immediately flanked by strong vertical plage
  fields of opposite polarity on each side of the filament. Because this
  isolated horizontal field is observed in photospheric lines, we infer
  that it is unlikely that the channel formed as a result of reconnection
  in the corona, but the low values of inferred magnetic fill fraction
  along the entire length of the filament channel suggest that the bulk
  of the field resides somewhat above the low photosphere. Correlation
  tracking of granulation in the G band presents no evidence for either
  systematic flows toward the channel or systematic shear flows along
  it. The absence of these flows, along with other indications of these
  data from multiple sources, reinforces (but does not conclusively
  demonstrate) the picture of an emerging flux rope as the origin of
  this AR filament channel.

Title: Quiescent Prominence Dynamics Observed with the Hinode Solar
    Optical Telescope. I. Turbulent Upflow Plumes
Authors: Berger, Thomas E.; Slater, Gregory; Hurlburt, Neal; Shine,
   Richard; Tarbell, Theodore; Title, Alan; Lites, Bruce W.; Okamoto,
   Takenori J.; Ichimoto, Kiyoshi; Katsukawa, Yukio; Magara, Tetsuya;
   Suematsu, Yoshinori; Shimizu, Toshifumi
Bibcode: 2010ApJ...716.1288B
Altcode:
  Hinode/Solar Optical Telescope (SOT) observations reveal two new
  dynamic modes in quiescent solar prominences: large-scale (20-50 Mm)
  "arches" or "bubbles" that "inflate" from below into prominences, and
  smaller-scale (2-6 Mm) dark turbulent upflows. These novel dynamics are
  related in that they are always dark in visible-light spectral bands,
  they rise through the bright prominence emission with approximately
  constant speeds, and the small-scale upflows are sometimes observed to
  emanate from the top of the larger bubbles. Here we present detailed
  kinematic measurements of the small-scale turbulent upflows seen in
  several prominences in the SOT database. The dark upflows typically
  initiate vertically from 5 to 10 Mm wide dark cavities between the
  bottom of the prominence and the top of the chromospheric spicule
  layer. Small perturbations on the order of 1 Mm or less in size
  grow on the upper boundaries of cavities to generate plumes up to
  4-6 Mm across at their largest widths. All plumes develop highly
  turbulent profiles, including occasional Kelvin-Helmholtz vortex
  "roll-up" of the leading edge. The flows typically rise 10-15 Mm before
  decelerating to equilibrium. We measure the flowfield characteristics
  with a manual tracing method and with the Nonlinear Affine Velocity
  Estimator (NAVE) "optical flow" code to derive velocity, acceleration,
  lifetime, and height data for several representative plumes. Maximum
  initial speeds are in the range of 20-30 km s<SUP>-1</SUP>, which
  is supersonic for a ~10,000 K plasma. The plumes decelerate in the
  final few Mm of their trajectories resulting in mean ascent speeds
  of 13-17 km s<SUP>-1</SUP>. Typical lifetimes range from 300 to 1000
  s (~5-15 minutes). The area growth rate of the plumes (observed as
  two-dimensional objects in the plane of the sky) is initially linear
  and ranges from 20,000 to 30,000 km<SUP>2</SUP> s<SUP>-1</SUP> reaching
  maximum projected areas from 2 to 15 Mm<SUP>2</SUP>. Maximum contrast of
  the dark flows relative to the bright prominence plasma in SOT images
  is negative and ranges from -10% for smaller flows to -50% for larger
  flows. Passive scalar "cork movies" derived from NAVE measurements show
  that prominence plasma is entrained by the upflows, helping to counter
  the ubiquitous downflow streams in the prominence. Plume formation
  shows no clear temporal periodicity. However, it is common to find
  "active cavities" beneath prominences that can spawn many upflows in
  succession before going dormant. The mean flow recurrence time in these
  active locations is roughly 300-500 s (5-8 minutes). Locations remain
  active on timescales of tens of minutes up to several hours. Using a
  column density ratio measurement and reasonable assumptions on plume
  and prominence geometries, we estimate that the mass density in the
  dark cavities is at most 20% of the visible prominence density, implying
  that a single large plume could supply up to 1% of the mass of a typical
  quiescent prominence. We hypothesize that the plumes are generated from
  a Rayleigh-Taylor instability taking place on the boundary between
  the buoyant cavities and the overlying prominence. Characteristics,
  such as plume size and frequency, may be modulated by the strength
  and direction of the cavity magnetic field relative to the prominence
  magnetic field. We conclude that buoyant plumes are a source of
  quiescent prominence mass as well as a mechanism by which prominence
  plasma is advected upward, countering constant gravitational drainage.

Title: Fundamental Solar Physics Results from Hinode and the Solar
    Dynamics Obervatory
Authors: Tarbell, Theodore D.
Bibcode: 2010AAS...21610601T
Altcode:
  Hinode is the most technologically advanced solar observatory ever <P
  />operated in space. It contains three instruments that provide major
  <P />improvements in spatial, temporal and spectral resolution over
  <P />previous solar space instruments. In its 3-year prime mission <P
  />(starting November, 2006) during low levels of solar activity, <P
  />observations have resulted in greatly improved understanding of the
  <P />interaction between convection and the solar magnetic fields and
  new <P />insights into the mechanisms that heat the solar atmosphere
  and <P />produce the UV and X-ray emission. Hinode results cover a
  wide range <P />of scientific issues that include the local solar
  dynamo, evidence for <P />the convective origin of sunspot penumbrae,
  the ubiquity of jets <P />formed by magnetic reconnection in the low
  solar atmosphere, the <P />presence of strong Alfven waves in the
  chromosphere and corona with <P />enough power to drive the solar
  wind, measurements of the free energy <P />powering solar eruptions,
  direct observations of current sheets formed <P />by Petschek-like
  reconnection driving CMEs, the presence of pervasive, <P />impulsive
  heating events in active regions that constrain coronal <P />heating
  models, and persistent outflows at the edges of active regions <P
  />that provide mass and energy to the solar wind. Solar Dynamics <P
  />Observatory (SDO), launched in February, 2010, has full disk imagers
  <P />with very high cadence to study the causes and predictability of
  <P />solar variability. In some important ways, Hinode will function
  as the <P />``microscope,'' both in spatial and spectral resolution,
  for SDO, just <P />as TRACE did for SOHO. Some initial examples of
  joint observations <P />will be shown.

Title: On the Origin of High-Frequency "Acoustic'' Power in
    Photospheric and Chromospheric Velocity Power Spectra
Authors: Fleck, Bernard; Straus, T.; Carlsson, M.; Jefferies, S. M.;
   Severino, G.; Tarbell, T. D.
Bibcode: 2010AAS...21640309F
Altcode: 2010BAAS...41..879F
  In a recent paper (Fleck et al., 2010) we compared observed Dopplergram
  time series from Hinode with results from 3-D numerical simulations
  based on the Oslo "Stagger” and CO5BOLD codes. Given the rapid falloff
  of atmospheric modulation transfer functions at high frequencies due
  to the extended widths of typical velocity response functions, one
  would expect the high-frequency tail of Doppler power spectra to drop
  significantly below those of actual velocities at the corresponding
  heights in the simulations. Surprisingly, our analysis of power spectra
  of Doppler shifts of simulated line profiles did not reveal such a
  steep falloff at high frequencies. Instead, they are comparable to
  (and in some cases even larger than) those of the actual velocities,
  making estimates of the energy flux of high frequency acoustic
  waves questionable, in particular those that apply atmospheric MTF
  corrections. In this work we study the cause of this unexpected
  behavior in detail, with particular emphasis on the role of rapidly
  changing velocity response functions in a dynamic atmosphere with
  strong vertical velocity gradients.

Title: Direct Imaging of an Emerging Flux Rope and a Resulting
    Chromospheric Jet Observed by Hinode
Authors: Liu, Wei; Berger, T.; Title, A. M.; Tarbell, T. D.; DeRosa, M.
Bibcode: 2010AAS...21640307L
Altcode: 2010BAAS...41R.878L
  Magnetic flux emergence has been traditionally observed on the disk by
  identifying changes in magnetograms. Observations near the limb offer
  an alternative perspective and allow direct imaging of emerging flux
  ropes. We present Hinode/SOT Ca II H observations of such an event in
  an equatorial coronal hole on 2007 February 9. The precursor of the
  event was a bundle of fine material threads that extended at an oblique
  angle above the chromosphere and appeared to rotate about a common
  axis. This bundle first slowly and then rapidly swung up, accompanied
  by a loop that appeared at the base of the bundle and expanded at
  comparable rates. During the first (slow rise) stage, the apex of the
  loop ascended at 16 km/s, a velocity similar to that of H-alpha arch
  filaments (e.g., Chou &amp; Zirin) and of emerging flux ropes expanding
  into the corona as found in MHD simulations (e.g., Fan &amp; Gibson;
  Martinez-Sykora). The second stage started at the onset of a GOES A5
  flare and the loop expansion accelerated, reaching a velocity of 130
  km/s when the loop appeared to rupture near the peak of the flare. The
  material bundle then swung back in a whiplike manner and developed into
  a collimated jet, exhibiting oscillatory transverse motions across its
  axis, as expected from unwinding twists. Some jet material fell back
  along smooth streamlines, which bypass an unseen dome and presumably
  a null point in the low corona, depicting an inverted-Y shape. Some
  of these observations resemble the model (e.g., Uchida &amp; Shibata)
  of the emergence of a twisted flux rope into an open field region that
  leads to reconnection and formation of a jet. Some observations are,
  however, not predicted in previous models and we will discuss their
  implications.

Title: High frequency waves in the solar atmosphere?.
Authors: Fleck, B.; Straus, T.; Carlsson, M.; Jefferies, S. M.;
   Severino, G.; Tarbell, T. D.
Bibcode: 2010MmSAI..81..777F
Altcode: 2010arXiv1002.3285F
  The present study addresses the following questions: How representative
  of the actual velocities in the solar atmosphere are the Doppler
  shifts of spectral lines? How reliable is the velocity signal derived
  from narrowband filtergrams? How well defined is the height of the
  measured Doppler signal? Why do phase difference spectra always pull
  to 0<SUP>o</SUP> phase lag at high frequencies? Can we actually observe
  high frequency waves (P&lt; 70 s)? What is the atmospheric MTF of high
  frequency waves? How reliably can we determine the energy flux of high
  frequency waves? We address these questions by comparing observations
  obtained with Hinode/NFI with results from two 3D numerical simulations
  (Oslo Stagger and CO<SUP>5</SUP>BOLD). Our results suggest that the
  observed high frequency Doppler velocity signal is caused by rapid
  height variations of the velocity response function in an atmosphere
  with strong velocity gradients and cannot be interpreted as evidence of
  propagating high frequency acoustic waves. Estimates of the energy flux
  of high frequency waves should be treated with caution, in particular
  those that apply atmospheric MTF corrections.

Title: On the detection of fast moving upflows in the quiet solar
    photosphere.
Authors: Straus, Th.; Fleck, B.; Jefferies, S. M.; Carlsson, M.;
   Tarbell, T. D.
Bibcode: 2010MmSAI..81..751S
Altcode: 2010arXiv1002.3305S
  In our studies of the dynamics and energetics of the solar atmosphere,
  we have detected, in high-quality observations from Hinode SOT/NFI,
  ubiquitous small-scale upflows which move horizontally with supersonic
  velocities in the quiet Sun. We present the properties of these fast
  moving upflows (FMUs) and discuss different interpretations.

Title: Joint STEREO-Hinode Observations of Coronal Dimming and Waves
    Associated with a CME/Flare Event
Authors: Nitta, Nariaki; Aschwanden, Markus; Frank, Zoe; Slater,
   Gregory; Tarbell, Theodore; Zarro, Dominic
Bibcode: 2010cosp...38.2928N
Altcode: 2010cosp.meet.2928N
  During the solar minimum between cycles 23 and 24, a number of
  minor flares from unimpressive active regions were associated with
  large-scale dimming and waves as observed by the EUV Imager (EUVI) on
  STEREO. We present a detailed study on one of the CME/flare events that
  was observed also by the instruments on Hinode. We analyze SOT Ca II
  data to explore the origin of the disturbances and EIS slit spectra to
  determine the timings of the upflow and associated turbulence that are
  presumably correlated with coronal dimming. The sequence of phenomena
  as captured by different instruments on STEREO, Hinode and SOHO helps
  us identify the key physical processes that gave rise to the event.

Title: Travel-Time Analyses of an Emerging-Flux Region
Authors: Nagashima, K.; Sekii, T.; Kosovichev, A. G.; Zhao, J.;
   Tarbell, T. D.
Bibcode: 2009ASPC..415..417N
Altcode:
  Travel-time analyses of a newly-formed plage region are presented. The
  dataset has been obtained from the 12-hr Hinode observation of an
  emerging-flux region (to be NOAA AR 10975) close to the disc center
  on 23 November 2007. The SOT provides data in Ca II H line and in
  Fe I 557.6nm line; we use both chromospheric intensity oscillation
  data and photospheric Dopplergrams for travel-time measurement by
  a cross-correlation method. In the plage region, we have detected
  a travel-time anomaly in the chromospheric data, but not in the
  photospheric data. This can be interpreted as a signature of downflows
  in the chromosphere. This result illustrates how time-distance
  techniques can be used to study chromospheric flows.

Title: An Intriguing Chromospheric Jet Observed by Hinode: Fine
    Structure Kinematics and Evidence of Unwinding Twists
Authors: Liu, Wei; Berger, Thomas E.; Title, Alan M.; Tarbell,
   Theodore D.
Bibcode: 2009ApJ...707L..37L
Altcode: 2009arXiv0910.5186L
  We report a chromospheric jet lasting for more than 1 hr observed by
  the Hinode Solar Optical Telescope in unprecedented detail. The ejection
  occurred in three episodes separated by 12-14 minutes, with the amount
  and velocity of material decreasing with time. The upward velocities
  range from 438 to 33 km\nolimits s\nolimits ^{-1}, while the downward
  velocities of the material falling back have smaller values (mean:
  -56 km\nolimits s\nolimits ^{-1}) and a narrower distribution (standard
  deviation: 14 km\nolimits s\nolimits ^{-1}). The average acceleration
  inferred from parabolic spacetime tracks is 141 m\nolimits s^{-2}, a
  fraction of the solar gravitational acceleration. The jet consists of
  fine threads (0farcs5-2'' wide), which exhibit coherent, oscillatory
  transverse motions perpendicular to the jet axis and about a common
  equilibrium position. These motions propagate upward along the jet,
  with the maximum phase speed of 744 ± 11 km\nolimits s\nolimits ^{-1}
  at the leading front of the jet. The transverse oscillation velocities
  range from 151 to 26 km\nolimits s\nolimits ^{-1}, amplitudes from
  6.0 to 1.9 Mm\nolimits, and periods from 250 to 536 s\nolimits. The
  oscillations slow down with time and cease when the material starts to
  fall back. The falling material travels along almost straight lines in
  the original direction of ascent, showing no transverse motions. These
  observations are consistent with the scenario that the jet involves
  untwisting helical threads, which rotate about the axis of a single
  large cylinder and shed magnetic helicity into the upper atmosphere.

Title: On the Role of Acoustic-Gravity Waves in the Energetics of
    the Solar Atmosphere
Authors: Straus, T.; Fleck, B.; Jefferies, S. M.; McIntosh, S. W.;
   Severino, G.; Steffen, M.; Tarbell, T. D.
Bibcode: 2009ASPC..415...95S
Altcode: 2010arXiv1003.3773S
  In a recent paper (Straus et al. 2008) we determined the energy
  flux of internal gravity waves in the lower solar atmosphere using
  a combination of 3D numerical simulations and observations obtained
  with the IBIS instrument operated at the Dunn Solar Telescope and
  the Michelson Doppler Imager (MDI) on SOHO. In this paper we extend
  these studies using coordinated observations from SOT/NFI and SOT/SP
  on Hinode and MDI. The new measurements confirm that gravity waves
  are the dominant phenomenon in the quiet middle/upper photosphere and
  that they transport more mechanical energy than the high-frequency
  (&gt; 5 mHz) acoustic waves, even though we find an acoustic flux 3-5
  times larger than the upper limit estimate of Fossum &amp; Carlsson
  (2006). It therefore appears justified to reconsider the significance of
  (non-M)HD waves for the energy balance of the solar chromosphere.

Title: Helical Shape and Twisting Motion as Intrinsic Properties of
    Penumbral Filaments
Authors: Shine, R. A.; Ryutova, M.; Berger, T. E.; Title, A. M.;
   Tarbell, T. D.; Ichimoto, K.
Bibcode: 2009AGUFMSH23B1541S
Altcode:
  A wealth of high resolution data obtained with advanced ground based
  telescopes and the SOT instrument on HINODE have led to new findings
  in the properties of penumbral filaments and controversies in their
  interpretation. Here we address one such issue, namely the question of
  whether the apparent twist of filaments is real or is just a viewing
  effect. We show that the helical shape and twisting motions of penumbral
  filaments follow from first principles and represent an integral part of
  penumbra formation and dynamics. As such, these properties link together
  other observed features of filaments including their magnetic and
  thermal substructure and their impact on the overlying atmosphere. At
  all stages of penumbral dynamics, qualitative agreement of theory and
  observations is supported by quantitative analysis as well.

Title: Role of the Resistive and Thermal Instabilities in Dynamics
    of Quiescent Prominences
Authors: Frank, Z.; Ryutova, M.; Berger, T. E.; Title, A. M.; Tarbell,
   T. D.
Bibcode: 2009AGUFMSH41B1653F
Altcode:
  We present the observations taken with the SOT instrument on Hinode in
  G-band and Ca H lines. High cadence data compiled in movies show clear
  evidence for several fundamental plasma instabilities. We combine
  the observational evidence and theoretical estimates to identify
  these instabilities. The following can be given as examples. (1)
  An analogue of the Kelvin-Helmholtz instability develops at the
  prominence/corona interface that manifests itself in growing ripples
  during a linear growth phase and may be followed by a nonlinear stage
  taking the form of an explosive instability corresponding to a CME
  ejection. This instability also includes the regime of "smoke ring"
  formation. (2) The appearence of "bubbles and spikes" typical to
  the Rayleigh-Taylor instability are observed. Their evolution and
  growth rates are found to be modified by both poloidal and toroidal
  components of magnetic field. (3) A resistive interchange instability,
  associated with an "unfavorable" magnetic field curvature relative to
  the density/temperature gradients, may be responsible for a hot barb
  formation, its evolution and collapse.

Title: Fine Structures and Kinematics of an Intriguing Chromospheric
    Jet Observed by Hinode Solar Optical Telescope
Authors: Liu, W.; Berger, T. E.; Title, A. M.; Tarbell, T. D.
Bibcode: 2009AGUFMSH51A1266L
Altcode:
  Transient, small-scale ejections of plasma from the lower atmosphere
  are common manifestations of solar activity. Hinode, with its superior
  resolutions, has spurred renewed interest in solar jets since its
  launch. Here we report a chromospheric jet lasting for more than 1
  hr on 2007 February 9 observed by the Hinode Solar Optical Telescope
  (SOT) in unprecedented detail. SOT Ca II H passband observations
  at high resolution of 0.2 arcsecond and cadence of 8 s allowed us to
  investigate the fine structures and kinematics of the jet. The ejection
  occurred in three episodes, rather than continuously, with the amount
  and velocity of material decreasing with time. The upward velocities
  along the jet range from ~440 to ~30 km/s, while the downward velocities
  of the material falling back have much smaller values (mean: -60 km/s)
  and a narrower distribution. Some tracks in the space-time plot clearly
  show parabolic shapes and the inferred acceleration is a fraction of
  the solar gravitational acceleration. The jet consists of fine threads
  (0.5-2 arcsecond wide), which exhibit coherent, oscillatory transverse
  motions perpendicular to the jet axis and about a common equilibrium
  position. These motions propagate upward, with the maximum phase speed
  of ~740 km/s found at the leading front of the jet. The transverse
  oscillation velocities range from 150 to 30 km/s, amplitudes from 6 to 2
  Mm, and periods from 250 to 550 s. The oscillations slow down with time
  and cease when the material starts to fall back. The falling material
  travels along almost straight lines in the original direction of ascent,
  showing no transverse motions. These observations are consistent with
  the models suggested by Shibata &amp; Uchida (1985) and Canfield et
  al. (1996). In this scenario, the jet involves untwisting helical
  threads, which rotate about the axis of a single large cylinder and
  shed magnetic helicity into the upper atmosphere. Implications of this
  event in the context of multiwavelength data in H-alpha, EUV, and X-rays
  will be discussed. A chromospheric jet observed by Hinode SOT in the
  Ca II H passband (T=1-2×10 4 K). Note the helical-like fine threads.

Title: Solar Surface Emerging Flux Regions: A Comparative Study of
    Radiative MHD Modeling and Hinode SOT Observations
Authors: Cheung, M.; Schüssler, M.; Tarbell, T. D.; Title, A. M.
Bibcode: 2009ASPC..415...79C
Altcode:
  We present results from three-dimensional radiative MHD simulations
  of the rise of buoyant magnetic flux tubes through the convection
  zone and into the photosphere. Due to the strong stratification
  of the convection zone, the rise results in a lateral expansion
  of the tube into a magnetic sheet, which acts as a reservoir for
  small-scale flux emergence events at the scale of granulation. The
  interaction of the convective downflows and the rising magnetic flux
  tube undulates it to form serpentine field lines that emerge into the
  photosphere. Observational characteristics of the simulated emerging
  flux regions are discussed in the context of new observations from
  Hinode SOT.

Title: Origin of Filamentary Structures and Flows in Quiescent
    Prominences
Authors: Ryutova, M.; Berger, T. E.; Tarbell, T. D.; Frank, Z.; Title,
   A. M.
Bibcode: 2009AGUFMSH23B1540R
Altcode:
  The paradox of fine vertical structure has usually referred to an
  apparent contradiction met when comparing vertical fine structures
  of quiescent prominences observed on the limb with the necessary
  horizontal magnetic field along their long axis. In addition to this
  fundamental problem, the very formation of fine vertical structures
  has been a long standing puzzle. Here we address these problems and
  show that considering the global structure of a prominence as a large
  scale skewed formation with toroidal and poloidal fields removes the
  paradox and allows derivation of dynamic stability criteria. This also
  includes the mechanism of the fine structure formation and peculiarities
  of downward mass motions. Theoretical estimates of key parameters
  are compared with the observations taken with the SOT instrument
  on Hinode. We find results of comparison very encouraging. For the
  approximate 3D reconstruction of the general shape of prominences,
  the STEREO A and B images have been used.

Title: A New View of Fine Scale Dynamics and Magnetism of Sunspots
    Revealed by Hinode/SOT
Authors: Ichimoto, K.; Suematsu, Y.; Katsukawa, Y.; Tsuneta, S.;
   Shimojo, M.; Shimizu, T.; Shine, R. A.; Tarbell, T. D.; Berger, T.;
   Title, A. M.; Lites, B. W.; Kubo, M.; Yokoyama, T.; Nagata, S.
Bibcode: 2009ASPC..405..167I
Altcode:
  The Solar Optical Telescope on-board Hinode is providing a new view of
  the fine scale dynamics in sunspots with its high spatial resolution and
  unprecedented image stability. We present three features related to the
  Evershed flow each of which raises a new puzzle in sunspot dynamics;
  i.e., twisting appearance of penumbral filaments, the source and sink
  of individual Evershed flow channels, and the net circular polarization
  in penumbrae with its spatial relation to the Evershed flow channels.

Title: Has Hinode Revealed the Missing Turbulent Flux of the
    Quiet Sun?
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A. M.; Ichimoto, K.; Katsukawa,
   Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2009ASPC..405..173L
Altcode:
  The Hinode Spectro-Polarimeter has revealed the presence of surprisingly
  strong horizontal magnetic fields nearly everywhere in the quiet
  solar atmosphere. These horizontal fields, along with measures of the
  vertical fields, may be the signature of the ``hidden turbulent flux''
  of the quiet Sun. The measured horizontal fields average at least to
  55 Gauss: nearly 5 times that of the measured longitudinal apparent
  flux density. The nature of these fields are reviewed, and discussed
  in the light of recent magneto-convection numerical simulations of
  the quiet Sun.

Title: Hinode Observation of the Magnetic Fields in a Sunspot Light
    Bridge Accompanied by Long-Lasting Chromospheric Plasma Ejections
Authors: Shimizu, Toshifumi; Katsukawa, Yukio; Kubo, Masahito; Lites,
   Bruce W.; Ichimoto, Kiyoshi; Suematsu, Yoshinori; Tsuneta, Saku;
   Nagata, Shin'ichi; Shine, Richard A.; Tarbell, Theodore D.
Bibcode: 2009ApJ...696L..66S
Altcode:
  We present high-resolution magnetic field measurements of a sunspot
  light bridge (LB) that produced chromospheric plasma ejections
  intermittently and recurrently for more than 1 day. The observations
  were carried out with the Hinode Solar Optical Telescope on 2007
  April 29 and 30. The spectro-polarimeter reveals obliquely oriented
  magnetic fields with vertical electric current density higher than
  100 mA m<SUP>-2</SUP> along the LB. The observations suggest that
  current-carrying highly twisted magnetic flux tubes are trapped below
  a cusp-shaped magnetic structure along the LB. The presence of trapped
  current-carrying flux tubes is essential for causing long-lasting
  chromospheric plasma ejections at the interface with pre-existing
  vertically oriented umbral fields. A bidirectional jet was clearly
  detected, suggesting magnetic reconnections occurring at very low
  altitudes, slightly above the height where the vector magnetic fields
  are measured. Moreover, we found another strong vertical electric
  current on the interface between the current-carrying flux tube
  and pre-existing umbral field, which might be a direct detection
  of the currents flowing in the current sheet formed at the magnetic
  reconnection sites.

Title: Magnetic Feature Tracking in Sunspot Moats Using Hinode/SOT
    Observations
Authors: Hagenaar-Daggett, Hermance J.; Shine, R. A.; Tarbell, T. D.
Bibcode: 2009SPD....40.0908H
Altcode:
  A long series of continuous observations of NOAA AR 10933 taken
  by Hinode/SOT from 2-4 January, 2007 is used to study MMF's (moving
  magnetic features) in the periphery of the large sunspot in the region
  and its surrounding moat. We describe some algorithms we have developed
  to quickly recognize and track discrete features and apply these to
  the magnetic structures seen in Na I 589.6nm Stokes V images. Because
  the features evolve and show variable visibilty, automatic tracking is
  not always successful even with the seeing free Hinode images and we
  are still attempting to improve our techniques. We also compute flow
  maps from the photospheric G band images using LCT (local correlation
  tracking) to compare with the generally faster MMF motions. <P />This
  work was supported by NASA contract NNM07AA01C.

Title: Recent Advances in Understanding Magnetic Fields in the
    Quiet Sun
Authors: Tarbell, Theodore D.
Bibcode: 2009SPD....40.0501T
Altcode:
  I will describe recent advances in our understanding of magnetic fields
  in the quiet sun. These have been developed both from high resolution
  observations made by the Hinode Solar Optical Telescope and ground-based
  observatories and from increasingly realistic three-dimensional MHD
  models of the upper convection zone and atmosphere. Examples of flux
  emergence, evolution, transport and disappearance are included. Some
  observational and theoretical problems in relating the photospheric
  fields to the upper atmosphere are discussed. <P />This work is
  supported by the NASA Hinode contract with the Lockheed Martin Advanced
  Technology Center.

Title: Prominence Formation Associated with an Emerging Helical
    Flux Rope
Authors: Okamoto, Takenori J.; Tsuneta, Saku; Lites, Bruce W.; Kubo,
   Masahito; Yokoyama, Takaaki; Berger, Thomas E.; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Nagata, Shin'ichi; Shibata, Kazunari; Shimizu,
   Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
   D.; Title, Alan M.
Bibcode: 2009ApJ...697..913O
Altcode: 2009arXiv0904.0007O
  The formation and evolution process and magnetic configuration of
  solar prominences remain unclear. In order to study the formation
  process of prominences, we examine continuous observations of a
  prominence in NOAA AR 10953 with the Solar Optical Telescope on
  the Hinode satellite. As reported in our previous Letter, we find
  a signature suggesting that a helical flux rope emerges from below
  the photosphere under a pre-existing prominence. Here we investigate
  more detailed properties and photospheric indications of the emerging
  helical flux rope, and discuss their relationship to the formation of
  the prominence. Our main conclusions are: (1) a dark region with absence
  of strong vertical magnetic fields broadens and then narrows in Ca II
  H-line filtergrams. This phenomenon is consistent with the emergence
  of the helical flux rope as photospheric counterparts. The size of the
  flux rope is roughly 30,000 km long and 10,000 km wide. The width is
  larger than that of the prominence. (2) No shear motion or converging
  flows are detected, but we find diverging flows such as mesogranules
  along the polarity inversion line. The presence of mesogranules may
  be related to the emergence of the helical flux rope. (3) The emerging
  helical flux rope reconnects with magnetic fields of the pre-existing
  prominence to stabilize the prominence for the next several days. We
  thus conjecture that prominence coronal magnetic fields emerge in
  the form of helical flux ropes that contribute to the formation and
  maintenance of the prominence.

Title: On The Interpretation Of Hinode NFI Filtergrams
Authors: Fleck, Bernard; Straus, T.; Jefferies, S. M.; Severino, G.;
   Tarbell, T. D.
Bibcode: 2009SPD....40.0927F
Altcode:
  Phase difference spectra between the velocity signals at two
  different heights represent a powerful tool to study the propagation
  characteristics of acoustic-gravity waves in the solar atmosphere. In
  our efforts to study the dynamics and energetics of these waves we
  have acquired high-resolution, high-cadence time series with Hinode
  SOT/NFI at two different levels in the Mg b2 or Na D1 lines. The
  observed phase spectra between the velocity signals derived from the
  "wing" and "core" filtergrams of these lines do not show the expected
  behavior. This points to (a) a fundamental lack of understanding of
  the propagation characteristics of acoustic waves, which may be more
  complex than commonly assumed, or (b) significant difficulties in
  interpreting filtergrams taken at fixed wavelengths in the wings of an
  absorption line, possibly limiting the diagnostic potential of Doppler
  "velocity" measurements from such filtergrams. The present work aims
  at disentangling these effects with the help of numerical simulations.

Title: Helioseismic Signature of Chromospheric Downflows in Acoustic
    Travel-Time Measurements From Hinode
Authors: Nagashima, Kaori; Sekii, Takashi; Kosovichev, Alexander G.;
   Zhao, Junwei; Tarbell, Theodore D.
Bibcode: 2009ApJ...694L.115N
Altcode: 2009arXiv0903.1323N
  We report on a signature of chromospheric downflows in two emerging
  flux regions detected by time-distance helioseismology analysis. We
  use both chromospheric intensity oscillation data in the Ca II H line
  and photospheric Dopplergrams in the Fe I 557.6 nm line obtained
  by Hinode/SOT for our analyses. By cross-correlating the Ca II
  oscillation signals, we have detected a travel-time anomaly in the
  plage regions; outward travel times are shorter than inward travel
  times by 0.5-1 minute. However, such an anomaly is absent in the Fe
  I data. These results can be interpreted as evidence of downflows in
  the lower chromosphere. The downflow speed is estimated to be below
  10 km s<SUP>-1</SUP>. This result demonstrates a new possibility of
  studying chromospheric flows by time-distance analysis.

Title: The Magnetic Landscape of the Sun's Polar Region
Authors: Tsuneta, S.; Ichimoto, K.; Katsukawa, Y.; Lites, B. W.;
   Matsuzaki, K.; Nagata, S.; Orozco Suárez, D.; Shimizu, T.; Shimojo,
   M.; Shine, R. A.; Suematsu, Y.; Suzuki, T. K.; Tarbell, T. D.; Title,
   A. M.
Bibcode: 2008ApJ...688.1374T
Altcode: 2008arXiv0807.4631T
  We present observations of the magnetic landscape of the polar region
  of the Sun that are unprecedented in terms of spatial resolution,
  field of view, and polarimetric precision. They were carried out with
  the Solar Optical Telescope aboard Hinode. Using a Milne-Eddington
  inversion, we find many vertically oriented magnetic flux tubes
  with field strengths as strong as 1 kG scattered in latitude between
  70° and 90°. They all have the same polarity, consistent with the
  global polarity of the polar region. The field vectors are observed to
  diverge from the centers of the flux elements, consistent with a view
  of magnetic fields that are expanding and fanning out with height. The
  polar region is also found to have ubiquitous horizontal fields. The
  polar regions are the source of the fast solar wind, which is channeled
  along unipolar coronal magnetic fields whose photospheric source is
  evidently rooted in the strong-field, vertical patches of flux. We
  conjecture that vertical flux tubes with large expansion around the
  photospheric-coronal boundary serve as efficient chimneys for Alfvén
  waves that accelerate the solar wind.

Title: Dynamics of the upper chromosphere
Authors: de Pontieu, B.; Carlsson, M.; McIntosh, S.; Hansteen, V.;
   Tarbell, T.
Bibcode: 2008AGUFMSH51C..05D
Altcode:
  In the past few years, high-resolution observations with ground-based
  telescopes and the Broadband Filter Imager (BFI) and Narrowband
  Filter Imager (NFI) of the Solar Optical Telescope onboard Hinode
  have revolutionized our view of the dynamics and energetics of
  the chromosphere. We review some of these results, including the
  discovery of two different types of spicules and the finding that the
  chromosphere is riddled with strong Alfvenic waves. We describe how
  these observations, when combined with advanced numerical simulations,
  can help address important unresolved issues regarding the connection
  between the photosphere and corona, such as the role of waves and
  of reconnection in driving the dynamics and energetics of the upper
  chromosphere, and how chromospheric dynamics impact the transition
  region and corona.

Title: Solar Surface Emerging Flux Regions: A Comparative Study of
    Radiative MHD Modeling and Hinode SOT Observations
Authors: Cheung, M. C. M.; Schüssler, M.; Tarbell, T. D.; Title, A. M.
Bibcode: 2008ApJ...687.1373C
Altcode: 2008arXiv0810.5723C
  We present results from numerical modeling of emerging flux regions
  on the solar surface. The modeling was carried out by means of
  three-dimensional (3D) radiative MHD simulations of the rise of
  buoyant magnetic flux tubes through the convection zone and into the
  photosphere. Due to the strong stratification of the convection zone,
  the rise results in a lateral expansion of the tube into a magnetic
  sheet, which acts as a reservoir for small-scale flux emergence
  events at the scale of granulation. The interaction of the convective
  downflows and the rising magnetic flux tube undulates it to form
  serpentine field lines that emerge into the photosphere. Observational
  characteristics, including the pattern of the emerging flux regions,
  the cancellation of surface flux and associated high-speed downflows,
  the convective collapse of photospheric flux tubes, the appearance
  of anomalous darkenings, the formation of bright points, and the
  possible existence of transient kilogauss horizontal fields are
  discussed in the context of new observations from the Hinode Solar
  Optical Telescope. Implications for the local helioseismology of
  emerging flux regions are also discussed.

Title: High Frequency Acoustic Waves in the Sun's Atmosphere
Authors: Fleck, B.; Jefferies, S. M.; McIntosh, S. W.; Severino, G.;
   Straus, T.; Tarbell, T. D.
Bibcode: 2008ESPM...12.2.39F
Altcode:
  This year marks the 60th anniversary of two pioneering papers by
  Schwarzschild (1948) and Biermann (1948), who independently proposed
  that acoustic waves generated in the turbulent convection zone play
  an important role in the heating of the chromosphere and corona. High
  frequency acoustic waves have remained one of the leading contenders
  for solving the heating problem of the non-magnetic chromospheres of
  the Sun and late-type stars ever since. Earlier attempts to determine
  the acoustic energy flux from ground were compromised by atmospheric
  seeing, which has its biggest effect on the high frequency parts
  of the observed signal. Recently, based on a comparison of TRACE
  observations and 1-D simulations, Fossum &amp; Carlsson (2005, 2006)
  concluded that high-frequency acoustic waves are not sufficient
  to heat the solar chromosphere. The same conclusion was reached by
  Carlsson et al. (2007) from an analysis of Hinode SOT/BFI Ca II H and
  blue continuum observations. Other authors (e.g. Cuntz et al. 2007;
  Wedemeyer-Boehm et al. 2007, Kalkofen 2007), however, questioned
  these results for a number of reasons. Because of its limited spatial
  resolution and limited sensitivity there are inherent difficulties
  when comparing TRACE observations with numerical simulations. Further,
  intensity oscillations are difficult to interpret, as they result from
  a phase-sensitive mix of temperature and pressure fluctuations, and
  non-local radiation transfer effects may complicate the picture even
  more. Here we revisit the role of high frequency acoustic waves in the
  dynamics and energetics of the Sun's atmosphere using high cadence,
  high resolution Doppler velocity measurements obtained with SOT/SP
  and SOT/NFI on Hinode.

Title: Magnetic Fields of the Quiet Sun: A New Quantitative
    Perspective From Hinode
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa, Y.;
   Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ASPC..397...17L
Altcode:
  This article summarizes results of studies presented in two papers
  already published: Lites et al. (2007a); Lites et al. (2007b). Please
  see these for further details.

Title: On-orbit Performance of the Solar Optical Telescope aboard
    Hinode
Authors: Ichimoto, K.; Katsukawa, Y.; Tarbell, T.; Shine, R. A.;
   Hoffmann, C.; Berger, T.; Cruz, T.; Suematsu, Y.; Tsuneta, S.; Shimizu,
   T.; Lites, B. W.
Bibcode: 2008ASPC..397....5I
Altcode: 2008arXiv0804.3248I
  On-orbit performance of the Solar Optical Telescope (SOT) aboard Hinode
  is described with some attention to its unpredicted aspects. In general,
  SOT reveals an excellent performance and has been providing outstanding
  data. Some unexpected features exist, however, in behaviours of the
  focus position, throughput and structural stability. Most of them are
  recovered by the daily operation i.e., frequent focus adjustment,
  careful heater setting and corrections in data analysis. The
  tunable filter contains air bubbles which degrade the data quality
  significantly. Schemes for tuning the filter without disturbing the
  bubbles have been developed and tested, and some useful procedures
  to obtain Dopplergrams and magnetograms are now available. October
  and March, when the orbit of satellite becomes nearly perpendicular
  to the direction towards the Sun, provide a favourable condition for
  continuous runs of the narrow-band filter imager.

Title: High Resolution Observations of Spicules with Hinode/SOT
Authors: Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Shimizu, T.;
   Okamoto, T.; Tsuneta, S.; Tarbell, T.; Shine, R. A.
Bibcode: 2008ASPC..397...27S
Altcode:
  High time cadence unprecedented images at the limb with Ca II H line
  filtergraph from the Solar Optical Telescope (SOT) aboard Hinode
  have revealed that a spicule consists of highly dynamic multi-threads
  (typically twin) as thin as a few tenths of an arcsecond, and shows
  prominent lateral movement or oscillation with rotation on its axis
  during its life. This multi-thread structure and lateral motion indicate
  that the spicules can be driven by magnetic reconnection at unresolved
  spatial scales at their footpoints.

Title: Evolution of Magnetic Fields at the Boundary of the Penumbra
Authors: Kubo, M.; Ichimoto, K.; Shimizu, T.; Lites, B. W.; Tsuneta,
   S.; Suematsu, Y.; Katsukawa, Y.; Nagata, S.; Tarbell, T.; Shine,
   R. A.; Title, A. M.
Bibcode: 2008ASPC..397...79K
Altcode:
  The formation of moving magnetic features (MMFs) separating from the
  penumbra were successfully observed with the Solar Optical Telescope
  (SOT) aboard the Hinode satellite. We find that bright features in
  the outer penumbra are located at the penumbral spines, which have
  magnetic fields more vertical than the surroundings, or located at the
  MMFs separating from the spines. This suggests that convection in the
  outer penumbra is related to the disintegration of the sunspot.

Title: On the Role of Acoustic-gravity Waves in the Energetics of
    the Solar Atmosphere
Authors: Straus, T.; Fleck, B.; Jefferies, S. M.; Cauzzi, G.; McIntosh,
   S. W.; Reardon, K.; Severino, G.; Steffen, M.; Suter, M.; Tarbell,
   T. D.
Bibcode: 2008ESPM...12.2.11S
Altcode:
  We revisit the dynamics and energetics of the solar atmosphere, using a
  combination of high-quality observations and 3D numerical simulations
  of the overshoot region of compressible convection into the stable
  photosphere. We discuss the contribution of acoustic-gravity waves
  to the energy balance of the photosphere and low chromosphere. We
  demonstrate the presence of propagating internal gravity waves at
  low frequencies (&lt; 5mHz). Surprisingly, these waves are found
  to be the dominant phenomenon in the quiet middle/upper photosphere
  and to transport a significant amount of mechanical energy into the
  atmosphere outweighing the contribution of high-frequency (&gt; 5mHz)
  acoustic waves by more than an order of magnitude. We compare the
  properties of high-frequency waves in the simulations with results
  of recent high cadence, high resolution Doppler velocity measurements
  obtained with SOT/SP and SOT/NFI on Hinode. Our results seem to be in
  conflict with the simple picture of upward propagating sound waves. We
  discuss the implications of our findings on the energy flux estimate
  at high-frequencies.

Title: Hinode Observations of Magnetic Elements in Internetwork Areas
Authors: de Wijn, A. G.; Lites, B. W.; Berger, T. E.; Frank, Z. A.;
   Tarbell, T. D.; Ishikawa, R.
Bibcode: 2008ApJ...684.1469D
Altcode: 2008arXiv0806.0345D
  We use sequences of images and magnetograms from Hinode to
  study magnetic elements in internetwork parts of the quiet solar
  photosphere. Visual inspection shows the existence of many long-lived
  (several hours) structures that interact frequently and may migrate
  over distances of ~7 Mm over a period of a few hours. About a fifth
  of the elements have an associated bright point in G-band or Ca
  II H intensity. We apply a hysteresis-based algorithm to identify
  elements. The algorithm is able to track elements for about 10 minutes
  on average. Elements intermittently drop below the detection limit,
  although the associated flux apparently persists and often reappears
  some time later. We infer proper motions of elements from their
  successive positions and find that they obey a Gaussian distribution
  with an rms of 1.57 +/- 0.08 km s<SUP>-1</SUP>. The apparent flows
  indicate a bias of about 0.2 km s<SUP>-1</SUP> toward the network
  boundary. Elements of negative polarity show a higher bias than elements
  of positive polarity, perhaps as a result of the dominant positive
  polarity of the network in the field of view or because of increased
  mobility due to their smaller size. A preference for motions in X is
  likely explained by higher supergranular flow in that direction. We
  search for emerging bipoles by grouping elements of opposite polarity
  that appear close together in space and time. We find no evidence
  supporting Joy's law at arcsecond scales.

Title: What do Spicules Tell us About the Chromosphere?
Authors: de Pontieu, B.; Carlsson, M.; McIntosh, S.; Hansteen, V.;
   Tarbell, T.
Bibcode: 2008ESPM...12.2.15D
Altcode:
  In the past few years, high-resolution observations with ground-based
  telescopes and the Broadband Filter Imager (BFI) and Narrowband
  Filter Imager (NFI) of the Solar Optical Telescope onboard
  Hinode have revolutionized our view of spicules and their role in
  the chromosphere. We review some of these results, including the
  discovery of two different types of spicules with different dynamics
  and formation mechanisms, as well as the finding that the chromosphere
  is riddled with strong Alfvenic waves. <P />In an effort to determine
  the formation mechanism of spicules and their impact on the outer
  atmosphere, we further focus on the thermal evolution and velocities
  developed by spicules. We use Dopplergrams made in the Na D 589.6 nm,
  H-alpha 656.3 nm and Mg B 517.3 nm passbands, as well as filtergrams in
  the Ca H 396.8 nm passband to study the spatio-temporal relationship
  between the various spicular features. We compare those findings with
  synthesized images based on line profiles computed from high-resolution
  3D MHD numerical simulations from the University of Oslo. We also use
  the Dopplergram data to investigate the velocities that develop in
  the two types of spicules that were reported previously. We perform
  statistical analysis of apparent velocities in the plane of the sky
  and line-of-sight velocities derived from Dopplergrams to disentangle
  the superposition of Alfvenic wave amplitudes and field-aligned
  flows. We study these properties for a variety of magnetic field
  configurations (coronal holes, quiet Sun, active region). Finally,
  we focus on the formation mechanism of spicules by analyzing spicular
  features in Dopplergrams on the disk that were taken simultaneously
  with SP magnetograms.

Title: Erratum: The Analysis of Penumbral Fine Structure Using an
    Advanced Inversion Technique
Authors: Jurcák, Jan; Bellot Rubio, Luis; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi;
   Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.; Tsuneta,
   Saku
Bibcode: 2008PASJ...60..933J
Altcode:
  In the article [PASJ 59, S601-S606 (2007)], the word ''CSIC'' was
  omitted from the affiliation of Dr. Luis Bellot Rubio. The correct
  affiliation is : <SUP>2</SUP>Instituto de Astrofísica de Andalucía
  (CSIC), Apdo. de Correos 3004, 18080 Granada, Spain

Title: Disintegration of Magnetic Flux in Decaying Sunspots as
    Observed with the Hinode SOT
Authors: Kubo, M.; Lites, B. W.; Ichimoto, K.; Shimizu, T.; Suematsu,
   Y.; Katsukawa, Y.; Tarbell, T. D.; Shine, R. A.; Title, A. M.; Nagata,
   S.; Tsuneta, S.
Bibcode: 2008ApJ...681.1677K
Altcode: 2008arXiv0806.0415K
  Continuous observations of sunspot penumbrae with the Solar Optical
  Telescope aboard Hinode clearly show that the outer boundary of the
  penumbra fluctuates around its averaged position. The penumbral outer
  boundary moves inward when granules appear in the outer penumbra. We
  discover that such granules appear one after another while moving
  magnetic features (MMFs) are separating from the penumbral "spines"
  (penumbral features that have fields that are stronger and more vertical
  than those of their surroundings). These granules that appear in the
  outer penumbra often merge with bright features inside the penumbra
  that move with the spines as they elongate toward the moat region. This
  suggests that convective motions around the penumbral outer boundary are
  related to the disintegration of magnetic flux in the sunspot. We also
  find that dark penumbral filaments frequently elongate into the moat
  region in the vicinity of MMFs that detach from penumbral spines. Such
  elongating dark penumbral filaments correspond to nearly horizontal
  fields extending from the penumbra. Pairs of MMFs with positive and
  negative polarities are sometimes observed along the elongating dark
  penumbral filaments. This strongly supports the notion that such
  elongating dark penumbral filaments have magnetic fields with a "sea
  serpent"-like structure. Evershed flows, which are associated with the
  penumbral horizontal fields, may be related to the detachment of the
  MMFs from the penumbral spines, as well as to the formation of the MMFs
  along the dark penumbral filaments that elongate into the moat region.

Title: Polarization Calibration of the Solar Optical Telescope
    onboard Hinode
Authors: Ichimoto, K.; Lites, B.; Elmore, D.; Suematsu, Y.; Tsuneta,
   S.; Katsukawa, Y.; Shimizu, T.; Shine, R.; Tarbell, T.; Title, A.;
   Kiyohara, J.; Shinoda, K.; Card, G.; Lecinski, A.; Streander, K.;
   Nakagiri, M.; Miyashita, M.; Noguchi, M.; Hoffmann, C.; Cruz, T.
Bibcode: 2008SoPh..249..233I
Altcode: 2008SoPh..tmp...69I
  The Solar Optical Telescope (SOT) onboard Hinode aims to obtain vector
  magnetic fields on the Sun through precise spectropolarimetry of
  solar spectral lines with a spatial resolution of 0.2 - 0.3 arcsec. A
  photometric accuracy of 10<SUP>−3</SUP> is achieved and, after the
  polarization calibration, any artificial polarization from crosstalk
  among Stokes parameters is required to be suppressed below the level
  of the statistical noise over the SOT's field of view. This goal was
  achieved by the highly optimized design of the SOT as a polarimeter,
  extensive analyses and testing of optical elements, and an end-to-end
  calibration test of the entire system. In this paper we review both
  the approach adopted to realize the high-precision polarimeter of the
  SOT and its final polarization characteristics.

Title: Image Stabilization System for Hinode (Solar-B) Solar Optical
    Telescope
Authors: Shimizu, T.; Nagata, S.; Tsuneta, S.; Tarbell, T.; Edwards,
   C.; Shine, R.; Hoffmann, C.; Thomas, E.; Sour, S.; Rehse, R.; Ito,
   O.; Kashiwagi, Y.; Tabata, M.; Kodeki, K.; Nagase, M.; Matsuzaki,
   K.; Kobayashi, K.; Ichimoto, K.; Suematsu, Y.
Bibcode: 2008SoPh..249..221S
Altcode:
  The Hinode Solar Optical Telescope (SOT) is the first space-borne
  visible-light telescope that enables us to observe magnetic-field
  dynamics in the solar lower atmosphere with 0.2 - 0.3 arcsec spatial
  resolution under extremely stable (seeing-free) conditions. To achieve
  precise measurements of the polarization with diffraction-limited
  images, stable pointing of the telescope (&lt;0.09 arcsec, 3σ) is
  required for solar images exposed on the focal plane CCD detectors. SOT
  has an image stabilization system that uses image displacements
  calculated from correlation tracking of solar granules to control
  a piezo-driven tip-tilt mirror. The system minimizes the motions
  of images for frequencies lower than 14 Hz while the satellite and
  telescope structural design damps microvibration in higher frequency
  ranges. It has been confirmed from the data taken on orbit that
  the remaining jitter is less than 0.03 arcsec (3σ) on the Sun. This
  excellent performance makes a major contribution to successful precise
  polarimetric measurements with 0.2 - 0.3 arcsec resolution.

Title: The Solar Optical Telescope for the Hinode Mission: An Overview
Authors: Tsuneta, S.; Ichimoto, K.; Katsukawa, Y.; Nagata, S.; Otsubo,
   M.; Shimizu, T.; Suematsu, Y.; Nakagiri, M.; Noguchi, M.; Tarbell,
   T.; Title, A.; Shine, R.; Rosenberg, W.; Hoffmann, C.; Jurcevich,
   B.; Kushner, G.; Levay, M.; Lites, B.; Elmore, D.; Matsushita, T.;
   Kawaguchi, N.; Saito, H.; Mikami, I.; Hill, L. D.; Owens, J. K.
Bibcode: 2008SoPh..249..167T
Altcode: 2008SoPh..tmp...74T; 2007arXiv0711.1715T
  The Solar Optical Telescope (SOT) aboard the Hinode satellite
  (formerly called Solar-B) consists of the Optical Telescope Assembly
  (OTA) and the Focal Plane Package (FPP). The OTA is a 50-cm
  diffraction-limited Gregorian telescope, and the FPP includes the
  narrowband filtergraph (NFI) and the broadband filtergraph (BFI), plus
  the Stokes Spectro-Polarimeter (SP). The SOT provides unprecedented
  high-resolution photometric and vector magnetic images of the
  photosphere and chromosphere with a very stable point spread function
  and is equipped with an image-stabilization system with performance
  better than 0.01 arcsec rms. Together with the other two instruments
  on Hinode (the X-Ray Telescope (XRT) and the EUV Imaging Spectrometer
  (EIS)), the SOT is poised to address many fundamental questions about
  solar magnetohydrodynamics. This paper provides an overview; the
  details of the instrument are presented in a series of companion papers.

Title: Frequent Occurrence of High-Speed Local Mass Downflows on
    the Solar Surface
Authors: Shimizu, T.; Lites, B. W.; Katsukawa, Y.; Ichimoto, K.;
   Suematsu, Y.; Tsuneta, S.; Nagata, S.; Kubo, M.; Shine, R. A.; Tarbell,
   T. D.
Bibcode: 2008ApJ...680.1467S
Altcode: 2008arXiv0804.1167S
  We report on new spectropolarimetric measurements with simultaneous
  filter imaging observation, revealing the frequent appearance of
  polarization signals indicating high-speed, probably supersonic,
  downflows that are associated with at least three different
  configurations of magnetic fields in the solar photosphere. The
  observations were carried out with the Solar Optical Telescope on
  board the Hinode satellite. High-speed downflows are excited when a
  moving magnetic feature is newly formed near the penumbral boundary of
  sunspots. Also, a new type of downflows is identified at the edge of
  sunspot umbra that lack accompanying penumbral structures. These may
  be triggered by the interaction of magnetic fields swept by convection
  with well-concentrated magnetic flux. Another class of high-speed
  downflows are observed in quiet Sun and sunspot moat regions. These are
  closely related to the formation of small concentrated magnetic flux
  patches. High-speed downflows of all types are transient time-dependent
  mass motions. These findings suggest that the excitation of supersonic
  mass flows are one of the key observational features of the dynamical
  evolution occurring in magnetic-field fine structures on the solar
  surface.

Title: Cooperative Observation of Ellerman Bombs between the Solar
    Optical Telescope aboard Hinode and Hida/Domeless Solar Telescope
Authors: Matsumoto, Takuma; Kitai, Reizaburo; Shibata, Kazunari;
   Nagata, Shin'ichi; Otsuji, Kenichi; Nakamura, Tahei; Watanabe, Hiroko;
   Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu,
   Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.; Lites, Bruce W.;
   Shine, Richard A.; Title, Alan M.
Bibcode: 2008PASJ...60..577M
Altcode:
  High-resolution CaIIH broad-band filter images of NOAA10933 on 2007
  January 5 were obtained by the Solar Optical Telescope aboard the Hinode
  satellite. Many small-scale (∼1") bright points were observed outside
  the sunspot and inside the emerging flux region. We identified some of
  these bright points with Ellerman bombs (EBs) by using Hα images taken
  by the Domeless Solar Telescope at Hida observatory. The sub-arcsec
  structures of two EBs seen in CaIIH were studied in detail. Our
  observation showed the following two aspects: (1) The CaIIH bright
  points identified with EBs were associated with the bipolar magnetic
  field structures, as reported by previous studies. (2)The structure
  of the CaIIH bright points turned out to consist of the following two
  parts: a central elongated bright core (0.7" × 0.5") located along
  the magnetic neutral line and a diffuse halo (1.2"×1.8").

Title: Velocities and thermal evolution of chromospheric spicules
Authors: de Pontieu, B.; McIntosh, S. W.; Tarbell, T.; Carlsson,
   M. P.; Hansteen, V. H.
Bibcode: 2008AGUSMSP53A..06D
Altcode:
  We use the Broadband Filter Imager (BFI) and Narrowband Filter
  Imager (NFI) of the Solar Optical Telescope on Hinode to study the
  thermal evolution and velocities developed by chromospheric plasma in
  spicules. We use Dopplergrams made in the Na D 589.6 nm, Hα 656.3 nm
  and Mg B 517.3 nm passbands, as well as filtergrams in the Ca H 396.8 nm
  passband to study the spatio-temporal relationship between the various
  spicular features. We compare those findings with synthesized images
  based on line profiles computed from high-resolution 3D MHD numerical
  simulations from the University of Oslo. We also use the Dopplergram
  data to investigate the velocities that develop in the two types of
  spicules that were reported previously. We perform statistical analysis
  of apparent velocities in the plane of the sky and line-of-sight
  velocities derived from Dopplergrams to disentangle the superposition
  of Alfvenic wave amplitudes and field-aligned flows. We study these
  properties for a variety of magnetic field configurations (coronal
  holes, quiet Sun, active region). Finally, we focus on the formation
  mechanism of spicules by analyzing spicular features in Dopplergrams
  on the disk that were taken simultaneously with SP magnetograms. This
  work was supported by NASA contract NNM07AA01C. The Hinode mission is
  operated by ISAS/JAXA, NAOJ, NASA, STFC, ESA and NSC.

Title: Emergence of a helical flux rope and prominence formation
Authors: Okamoto, T. J.; Tsuneta, S.; Lites, B. W.; Kubo, M.; Yokoyama,
   T.; Berger, T. E.; Ichimoto, K.; Katsukawa, Y.; Nagata, S.; Shibata,
   K.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title,
   A. M.
Bibcode: 2008AGUSMSP43B..06O
Altcode:
  We report a discovery about emergence of a helical flux rope. The
  episode may be related to the formation and evolution of an active
  region prominence. Statistical studies by previous authors indicate that
  numerous prominences have the inverse-polarity configuration suggesting
  the helical magnetic configurations. There are two theoretical
  models about formation of such a coronal helical magnetic field in
  association with prominences: flux rope model and sheared-arcade
  model. We have so far no clear observational evidence to support
  either model. In order to find a clue about the formation of the
  prominence, we had continuous observations of NOAA AR 10953 with the
  SOT during 2007 April 28 to May 9. A prominence was located over the
  polarity inversion line in the south-east of the main sunspot. These
  observations provided us with a time series of vector magnetic fields
  on the photosphere under the prominence. We found four new features:
  (1) The abutting opposite-polarity regions on the two sides along
  the polarity inversion line first grew laterally in size and then
  narrowed. (2) These abutting regions contained vertically-weak,
  but horizontally-strong magnetic fields. (3) The orientations of
  the horizontal magnetic fields along the polarity inversion line on
  the photosphere gradually changed with time from a normal- polarity
  configuration to an inverse-polarity one. (4) The horizontal-magnetic
  field region was blueshifted. These indicate that helical flux rope
  emerges from below the photosphere into the corona along the polarity
  inversion line under the prominence. We suggest that this supply of a
  helical magnetic flux possibly into the corona is related to formation
  and maintenance of active-region prominences.

Title: Chromospheric Flows in the Vicinity of Magnetic Features in
    the Quiet Sun Observed with Hinode SOT
Authors: Tarbell, T.; de Pontieu, B.; Carlsson, M.; Hansteen, V.;
   McIntosh, S.; Ichimoto, K.
Bibcode: 2008AGUSMSP41B..02T
Altcode:
  The Narrowband Filter Imager of the Solar Optical Telescope on Hinode
  can measure Doppler shifts and line-of- sight magnetic fields in two
  lines with contributions from the low chromosphere: Na D 589.6 nm and
  Mg b 517.3 nm. The SOT Spectro-Polarimeter also measures very accurate
  vector magnetic fields and Doppler velocities in the photosphere. These
  observations have diffraction-limited spatial resolution and superb
  stability. We present examples of these measurements in quiet sun
  at various disk positions. In addition to the expected granulation
  and f- and p-modes, conspicuous longer-lived downflows are seen near
  strong network flux elements. Transient upflows are also detected,
  presumably the base of flows seen in spicules at the limb and H-alpha
  mottles on the disk. Velocity features associated with emerging and
  cancelling magnetic features are also described. The observations are
  compared with synthesized images made from line profiles computed from
  the University of Oslo 3-D MHD simulations. This work was supported by
  NASA contract NNM07AA01C. The Hinode mission is operated by ISAS/JAXA,
  NAOJ, NASA, STFC, ESA and NSC.

Title: Photospheric Signature of Penumbral Microjets
Authors: Katsukawa, Y.; Jurcak, J.; Ichimoto, K.; Suemtasu, Y.;
   Tsuneta, S.; Shimizu, T.; Berger, T. E.; Shine, R. A.; Tarbell, T. D.;
   Lites, B. W.
Bibcode: 2008AGUSMSP53A..03K
Altcode:
  HINODE Solar Optical Telescope (SOT) discovered ubiquitous occurrence
  of fine-scale jetlike activities in penumbral chromospheres, which
  are referred to as penumbral microjets. The microjets' small width
  of 400 km and short duration of less than 1 min make them difficult
  to identify in existing ground-based observations. The apparent
  rise velocity is faster than 50km/s and is roughly comparable to
  the Alfven speed in the sunspot chromosphere. These properties of
  penumbral microjets suggest that magnetic reconnection in uncombed
  magnetic field configuration is the most possible cause of penumbral
  microjets. In order to understand magnetic configuration associated with
  penumbral microjets and prove the chromospheric magnetic reconnection
  hypothesis, we investigated relationship between penumbral microjets
  seen in CaIIH images and photospheric magnetic fields measured by
  the HINODE spectro-polarimeter. We found the inclination angles of
  penumbral microjets measured in CaII H images are roughly consistent
  with inclination angles of relatively vertical magnetic field
  component in uncombed magnetic field configuration. In addition,
  strong and transient downflows are observed in the photosphere near
  the boundary of a horizontal flux tube associated with a penumbral
  microjet. The size of the downflow region is about 300km, which is
  close to the width of penumbral microjets seen in CaII H images. The
  downflow velocity of several km/s might be a result of an outflow of
  chromospheric magnetic reconnection and suffer deceleration due to
  the higher density in the photosphere.

Title: Non-Linear Force-Free Field Modeling of a Solar Active Region
    Around the Time of a Major Flare and Coronal Mass Ejection
Authors: De Rosa, M. L.; Schrijver, C. J.; Metcalf, T. R.; Barnes,
   G.; Lites, B.; Tarbell, T.; McTiernan, J.; Valori, G.; Wiegelmann,
   T.; Wheatland, M.; Amari, T.; Aulanier, G.; Démoulin, P.; Fuhrmann,
   M.; Kusano, K.; Régnier, S.; Thalmann, J.
Bibcode: 2008AGUSMSP31A..06D
Altcode:
  Solar flares and coronal mass ejections are associated with rapid
  changes in coronal magnetic field connectivity and are powered by
  the partial dissipation of electrical currents that run through
  the solar corona. A critical unanswered question is whether the
  currents involved are induced by the advection along the photosphere
  of pre-existing atmospheric magnetic flux, or whether these currents
  are associated with newly emergent flux. We address this problem by
  applying nonlinear force-free field (NLFFF) modeling to the highest
  resolution and quality vector-magnetographic data observed by the
  recently launched Hinode satellite on NOAA Active Region 10930 around
  the time of a powerful X3.4 flare in December 2006. We compute 14
  NLFFF models using 4 different codes having a variety of boundary
  conditions. We find that the model fields differ markedly in geometry,
  energy content, and force-freeness. We do find agreement of the best-fit
  model field with the observed coronal configuration, and argue (1)
  that strong electrical currents emerge together with magnetic flux
  preceding the flare, (2) that these currents are carried in an ensemble
  of thin strands, (3) that the global pattern of these currents and
  of field lines are compatible with a large-scale twisted flux rope
  topology, and (4) that the ~1032~erg change in energy associated with
  the coronal electrical currents suffices to power the flare and its
  associated coronal mass ejection. We discuss the relative merits of
  these models in a general critique of our present abilities to model
  the coronal magnetic field based on surface vector field measurements.

Title: Disintegration of Magnetic Flux in Decaying Sunspots as
    Observed with the Hinode/SOT
Authors: Kubo, M.; Lites, B. W.; Ichimoto, K.; Shimizu, T.; Suematsu,
   Y.; Katsukawa, Y.; Tarbell, T. D.; Shine, R. A.; Title, A. M.; Nagata,
   S.; Tsuneta, S.
Bibcode: 2008AGUSMSP31B..01K
Altcode:
  Continuous observations of sunspot penumbrae with the Solar Optical
  Telescope aboard Hinode clearly show that the outer boundary of the
  penumbra fluctuates around its averaged position. The penumbral outer
  boundary moves inward when granules appear in the outer penumbra. We
  discover that such granules appear one after another while moving
  magnetic features (MMFs) are separating from the penumbral "spines"
  (penumbral features having fields that are stronger and more vertical
  than their surroundings). These granules that appear in the outer
  penumbra often merge with bright features inside the penumbra that move
  with spines as they elongate toward the moat region. This suggests that
  convective motions around the penumbral outer boundary are related to
  disintegration of magnetic flux in the sunspot. We also find that dark
  penumbral filaments frequently elongate into the moat region in the
  vicinity of MMFs that detach from penumbral spines. Such elongating
  dark penumbral filaments correspond to nearly horizontal fields
  extending from the penumbra. Pairs of MMFs with positive and negative
  polarities are sometimes observed along the elongating dark penumbral
  filaments. This strongly supports the notion that such elongating dark
  penumbral filaments have magnetic fields with a "sea serpent"-like
  structure. Evershed flows, which are associated with the penumbral
  horizontal fields, may be related to detachment of the MMFs from the
  penumbral spines, as well as to the formation of the MMFs along the
  dark penumbral filaments that elongate into the moat region.

Title: Quiescent Prominence Structure and Dynamics: a new View From
    the Hinode/SOT
Authors: Berger, T.; Okamoto, J.; Slater, G.; Magara, T.; Tarbell,
   T.; Tsuneta, S.; Hurlburt, N.
Bibcode: 2008AGUSMSP53A..01B
Altcode:
  To date the Hinode/Solar Optical Telescope (SOT) has produced over a
  dozen sub-arcsecond, multi-hour movies of quiescent solar prominences
  in both the Ca II 396.8~nm H-line and the H-alpha 656.3~nm line. These
  datasets have revealed new details of the structure and dynamics of
  quiescent prominences including a new form of mass transport in the
  form of buoyant plume upflows from the chromosphere. We review the
  SOT prominence datasets to show that quiescent prominences appear in
  two major morphological categories: "vertically" and "horizontally"
  structured. The vertically structured prominences all show ubiquitous
  downflows in 400--700~km wide "streams" with velocities of approximately
  10~km~s-1. Most of the vertically structured prominences also show
  episodic upflows in the form of dark turbulent plumes with typical
  velocities of 20~km~s-1. Large-scale oscillations are frequently
  seen in vertical prominences with periods on the order of 10 min and
  upward propagation speeds of approximately 10~km~s-1. In addition,
  "bubble" events in which large voids 10--30~Mm across inflate and
  then burst are seen in some of the vertical prominences. In contrast,
  the horizontally structured quiescent prominences exhibit only limited
  flows along the horizontal filaments. We speculate on the origin of
  the distinction between the vertically and horizontally structured
  prominences, taking into account viewing angle and the underlying
  photospheric magnetic flux density. We also discuss the nature of the
  mysterious dark plumes and bubble expansions and their implications
  for prominence mass balance in light of recent models of prominence
  magnetic structure that find vertical flows along some field lines.

Title: High Frequency Acoustic Waves in the Sun's Atmosphere
Authors: Fleck, B.; Jefferies, S. M.; McIntosh, S. W.; Straus, T.;
   Tarbell, T. D.
Bibcode: 2008AGUSMSP41B..04F
Altcode:
  This year marks the 60th anniversary of two pioneering papers by
  Schwarzschild (1948) and Biermann (1948), who independently proposed
  that acoustic waves generated in the turbulent convection zone play
  an important role in the heating of the chromosphere and corona. High
  frequency acoustic waves have remained one of the leading contenders
  for solving the heating problem of the non-magnetic chromospheres of
  the Sun and late-type stars ever since. Earlier attempts to determine
  the acoustic energy flux from ground were compromised by atmospheric
  seeing, which has its biggest effect on the high frequency parts
  of the observed signal. Recently, based on a comparison of TRACE
  observations and 1-D simulations, Fossum &amp; Carlsson (2005, 2006)
  concluded that high-frequency acoustic waves are not sufficient to heat
  the solar chromosphere. The same conclusion was reached by Carlsson et
  al. (2007) from an analysis of Hinode SOT/BFI Ca II H and blue continuum
  observations. Other authors (e.g. Cuntz et al. 2007; Wedemeyer-Boehm
  et al. 2007, Kalkofen 2007), however, questioned these results for
  a number of reasons. Because of its limited spatial resolution and
  limited sensitivity there are inherent difficulties when comparing TRACE
  observations with numerical simulations. Further, intensity oscillations
  are difficult to interpret, as they result from a phase-sensitive mix of
  density, temperature, and pressure fluctuations, and radiation transfer
  effects may complicate the picture even more. Here we revisit the role
  of high frequency acoustic waves in the Sun's atmosphere using high
  cadence, high resolution Doppler velocity measurements obtained with
  SOT/SP and SOT/NFI on Hinode.

Title: Formation of Solar Magnetic Flux Tubes with Kilogauss Field
    Strength Induced by Convective Instability
Authors: Nagata, Shin'ichi; Tsuneta, Saku; Suematsu, Yoshinori;
   Ichimoto, Kiyoshi; Katsukawa, Yukio; Shimizu, Toshifumi; Yokoyama,
   Takaaki; Tarbell, Theodore D.; Lites, Bruce W.; Shine, Richard A.;
   Berger, Thomas E.; Title, Alan M.; Bellot Rubio, Luis R.; Orozco
   Suárez, David
Bibcode: 2008ApJ...677L.145N
Altcode:
  Convective instability has been a mechanism used to explain
  the formation of solar photospheric flux tubes with kG field
  strength. However, the turbulence of the Earth's atmosphere has
  prevented ground-based observers from examining the hypothesis
  with precise polarimetric measurement on the subarcsecond scale
  flux tubes. Here we discuss observational evidence of this scenario
  based on observations with the Solar Optical Telescope (SOT) aboard
  Hinode. The cooling of an equipartition field strength flux tube
  precedes a transient downflow reaching 6 km s<SUP>-1</SUP> and the
  intensification of the field strength to 2 kG. These observations
  agree very well with the theoretical predictions.

Title: Transient horizontal magnetic fields in solar plage regions
Authors: Ishikawa, R.; Tsuneta, S.; Ichimoto, K.; Isobe, H.; Katsukawa,
   Y.; Lites, B. W.; Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu,
   Y.; Tarbell, T. D.; Title, A. M.
Bibcode: 2008A&A...481L..25I
Altcode: 2008arXiv0802.1769I
  Aims:We report the discovery of isolated, small-scale emerging
  magnetic fields in a plage region with the Solar Optical Telescope
  aboard Hinode. <BR />Methods: Spectro-polarimetric observations were
  carried out with a cadence of 34 s for the plage region located near
  disc center. The vector magnetic fields are inferred by Milne-Eddington
  inversion. <BR />Results: The observations reveal widespread occurrence
  of transient, spatially isolated horizontal magnetic fields. The
  lateral extent of the horizontal magnetic fields is comparable to
  the size of photospheric granules. These horizontal magnetic fields
  seem to be tossed about by upflows and downflows of the granular
  convection. We also report an event that appears to be driven by the
  magnetic buoyancy instability. We refer to buoyancy-driven emergence
  as type 1 and convection-driven emergence as type 2. Although both
  events have magnetic field strengths of about 600 G, the filling
  factor of type 1 is a factor of two larger than that of type 2. <BR
  />Conclusions: Our finding suggests that the granular convection in
  the plage regions is characterized by a high rate of occurrence of
  granular-sized transient horizontal fields.

Title: Net circular polarization of sunspots in high spatial
    resolution
Authors: Ichimoto, K.; Tsuneta, S.; Suematsu, Y.; Katsukawa, Y.;
   Shimizu, T.; Lites, B. W.; Kubo, M.; Tarbell, T. D.; Shine, R. A.;
   Title, A. M.; Nagata, S.
Bibcode: 2008A&A...481L...9I
Altcode:
  Context: Net circular polarization (NCP) of spectral lines in
  sunspots has been most successfully explained by the presense of
  discontinuities in the magnetic field inclination and flow velocity
  along the line-of-sight in the geometry of the embedded flux tube model
  of penumbrae (Δγ-effect). <BR />Aims: The fine scale structure of
  NCP in a sunspot is examined with special attention paid to spatial
  relations of the Evershed flow to confirm the validity of the present
  interpretation of the NCP of sunspots. <BR />Methods: High resolution
  spectro-polarimetric data of a positive-polarity sunspot obtained
  by the Solar Optical Telescope aboard Hinode are analysed. <BR
  />Results: A positive NCP is associated with the Evershed flow
  channels in both limb-side and disk center-side penumbrae and with
  upflows in the penumbra at disk center. The negative NCP in the disk
  center-side penumbra is generated in inter-Evershed flow channels. <BR
  />Conclusions: The first result is apparently inconsistent with the
  current explanation of NCP with the Δγ-effect but rather suggests a
  positive correlation between the magnetic field strength and the flow
  velocity as the cause of the NCP. The second result serves as strong
  evidence for the presence of gas flows in inter-Evershed flow channels.

Title: Sun Earth Connection Coronal and Heliospheric Investigation
    (SECCHI)
Authors: Howard, R. A.; Moses, J. D.; Vourlidas, A.; Newmark, J. S.;
   Socker, D. G.; Plunkett, S. P.; Korendyke, C. M.; Cook, J. W.; Hurley,
   A.; Davila, J. M.; Thompson, W. T.; St Cyr, O. C.; Mentzell, E.;
   Mehalick, K.; Lemen, J. R.; Wuelser, J. P.; Duncan, D. W.; Tarbell,
   T. D.; Wolfson, C. J.; Moore, A.; Harrison, R. A.; Waltham, N. R.;
   Lang, J.; Davis, C. J.; Eyles, C. J.; Mapson-Menard, H.; Simnett,
   G. M.; Halain, J. P.; Defise, J. M.; Mazy, E.; Rochus, P.; Mercier,
   R.; Ravet, M. F.; Delmotte, F.; Auchere, F.; Delaboudiniere, J. P.;
   Bothmer, V.; Deutsch, W.; Wang, D.; Rich, N.; Cooper, S.; Stephens,
   V.; Maahs, G.; Baugh, R.; McMullin, D.; Carter, T.
Bibcode: 2008SSRv..136...67H
Altcode: 2008SSRv..tmp...64H
  The Sun Earth Connection Coronal and Heliospheric Investigation
  (SECCHI) is a five telescope package, which has been developed for
  the Solar Terrestrial Relation Observatory (STEREO) mission by the
  Naval Research Laboratory (USA), the Lockheed Solar and Astrophysics
  Laboratory (USA), the Goddard Space Flight Center (USA), the University
  of Birmingham (UK), the Rutherford Appleton Laboratory (UK), the
  Max Planck Institute for Solar System Research (Germany), the Centre
  Spatiale de Leige (Belgium), the Institut d’Optique (France) and the
  Institut d’Astrophysique Spatiale (France). SECCHI comprises five
  telescopes, which together image the solar corona from the solar disk to
  beyond 1 AU. These telescopes are: an extreme ultraviolet imager (EUVI:
  1 1.7 R<SUB>⊙</SUB>), two traditional Lyot coronagraphs (COR1: 1.5 4
  R<SUB>⊙</SUB> and COR2: 2.5 15 R<SUB>⊙</SUB>) and two new designs
  of heliospheric imagers (HI-1: 15 84 R<SUB>⊙</SUB> and HI-2: 66 318
  R<SUB>⊙</SUB>). All the instruments use 2048×2048 pixel CCD arrays
  in a backside-in mode. The EUVI backside surface has been specially
  processed for EUV sensitivity, while the others have an anti-reflection
  coating applied. A multi-tasking operating system, running on a PowerPC
  CPU, receives commands from the spacecraft, controls the instrument
  operations, acquires the images and compresses them for downlink
  through the main science channel (at compression factors typically
  up to 20×) and also through a low bandwidth channel to be used for
  space weather forecasting (at compression factors up to 200×). An
  image compression factor of about 10× enable the collection of images
  at the rate of about one every 2 3 minutes. Identical instruments,
  except for different sizes of occulters, are included on the STEREO-A
  and STEREO-B spacecraft.

Title: Nonlinear Force-free Field Modeling of a Solar Active Region
    around the Time of a Major Flare and Coronal Mass Ejection
Authors: Schrijver, C. J.; DeRosa, M. L.; Metcalf, T.; Barnes, G.;
   Lites, B.; Tarbell, T.; McTiernan, J.; Valori, G.; Wiegelmann, T.;
   Wheatland, M. S.; Amari, T.; Aulanier, G.; Démoulin, P.; Fuhrmann,
   M.; Kusano, K.; Régnier, S.; Thalmann, J. K.
Bibcode: 2008ApJ...675.1637S
Altcode: 2007arXiv0712.0023S
  Solar flares and coronal mass ejections are associated with rapid
  changes in field connectivity and are powered by the partial dissipation
  of electrical currents in the solar atmosphere. A critical unanswered
  question is whether the currents involved are induced by the motion of
  preexisting atmospheric magnetic flux subject to surface plasma flows or
  whether these currents are associated with the emergence of flux from
  within the solar convective zone. We address this problem by applying
  state-of-the-art nonlinear force-free field (NLFFF) modeling to the
  highest resolution and quality vector-magnetographic data observed
  by the recently launched Hinode satellite on NOAA AR 10930 around
  the time of a powerful X3.4 flare. We compute 14 NLFFF models with
  four different codes and a variety of boundary conditions. We find
  that the model fields differ markedly in geometry, energy content,
  and force-freeness. We discuss the relative merits of these models in
  a general critique of present abilities to model the coronal magnetic
  field based on surface vector field measurements. For our application
  in particular, we find a fair agreement of the best-fit model field
  with the observed coronal configuration, and argue (1) that strong
  electrical currents emerge together with magnetic flux preceding the
  flare, (2) that these currents are carried in an ensemble of thin
  strands, (3) that the global pattern of these currents and of field
  lines are compatible with a large-scale twisted flux rope topology,
  and (4) that the ~10<SUP>32</SUP> erg change in energy associated with
  the coronal electrical currents suffices to power the flare and its
  associated coronal mass ejection.

Title: Hinode SOT Observations of Solar Quiescent Prominence Dynamics
Authors: Berger, Thomas E.; Shine, Richard A.; Slater, Gregory L.;
   Tarbell, Theodore D.; Title, Alan M.; Okamoto, Takenori J.; Ichimoto,
   Kiyoshi; Katsukawa, Yukio; Suematsu, Yoshinori; Tsuneta, Saku; Lites,
   Bruce W.; Shimizu, Toshifumi
Bibcode: 2008ApJ...676L..89B
Altcode:
  We report findings from multihour 0.2'' resolution movies of
  solar quiescent prominences (QPs) observed with the Solar Optical
  Telescope (SOT) on the Hinode satellite. The observations verify
  previous findings of filamentary downflows and vortices in QPs. SOT
  observations also verify large-scale transverse oscillations in QPs,
  with periods of 20-40 minutes and amplitudes of 2-5 Mm. The upward
  propagation speed of several waves is found to be ~10 km s<SUP>-1</SUP>,
  comparable to the sound speed of a 10,000 K plasma, implying that
  the waves are magnetoacoustic in origin. Most significantly, Hinode
  SOT observations reveal that dark, episodic upflows are common in
  QPs. The upflows are 170-700 km in width, exhibit turbulent flow,
  and rise with approximately constant speeds of ~20 km s<SUP>-1</SUP>
  from the base of the prominence to heights of ~10-20 Mm. The upflows
  are visible in both the Ca II H-line and Hα bandpasses of SOT. The new
  flows are seen in about half of the QPs observed by SOT to date. The
  dark upflows resemble buoyant starting plumes in both their velocity
  profile and flow structure. We discuss thermal and magnetic mechanisms
  as possible causes of the plumes.

Title: Reappraising Transition Region Line Widths in Light of Recent
    Alfvén Wave Discoveries
Authors: McIntosh, Scott W.; De Pontieu, Bart; Tarbell, Theodore D.
Bibcode: 2008ApJ...673L.219M
Altcode: 2008arXiv0801.0671M
  We provide a new interpretation of ultraviolet transition region
  emission line widths observed by the SUMER instrument on the Solar
  and Heliospheric Observatory (SOHO). This investigation is prompted
  by observations of the chromosphere at unprecedented spatial and
  temporal resolution from the Solar Optical Telescope (SOT) on Hinode
  revealing that all chromospheric structures above the limb display
  significant transverse (Alfvénic) perturbations. We demonstrate
  that the magnitude, network sensitivity, and apparent center-to-limb
  isotropy of the measured line widths (formed below 250,000 K) can be
  explained by an observationally constrained forward model in which the
  line width is caused by the line-of-sight superposition of longitudinal
  and Alfvénic motions on the small-scale (spicular) structures that
  dominate the chromosphere and low transition region.

Title: Emergence of a Helical Flux Rope under an Active Region
    Prominence
Authors: Okamoto, Takenori J.; Tsuneta, Saku; Lites, Bruce W.; Kubo,
   Masahito; Yokoyama, Takaaki; Berger, Thomas E.; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Nagata, Shin'ichi; Shibata, Kazunari; Shimizu,
   Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
   D.; Title, Alan M.
Bibcode: 2008ApJ...673L.215O
Altcode: 2008arXiv0801.1956O
  Continuous observations were obtained of NOAA AR 10953 with the Solar
  Optical Telescope (SOT) on board the Hinode satellite from 2007 April
  28 to May 9. A prominence was located over the polarity inversion
  line (PIL) to the southeast of the main sunspot. These observations
  provided us with a time series of vector magnetic fields on the
  photosphere under the prominence. We found four features: (1) The
  abutting opposite-polarity regions on the two sides along the PIL first
  grew laterally in size and then narrowed. (2) These abutting regions
  contained vertically weak but horizontally strong magnetic fields. (3)
  The orientations of the horizontal magnetic fields along the PIL on
  the photosphere gradually changed with time from a normal-polarity
  configuration to an inverse-polarity one. (4) The horizontal magnetic
  field region was blueshifted. These indicate that helical flux rope
  was emerging from below the photosphere into the corona along the PIL
  under the preexisting prominence. We suggest that this supply of a
  helical magnetic flux to the corona is associated with evolution and
  maintenance of active region prominences.

Title: The Horizontal Magnetic Flux of the Quiet-Sun Internetwork
    as Observed with the Hinode Spectro-Polarimeter
Authors: Lites, B. W.; Kubo, M.; Socas-Navarro, H.; Berger, T.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa, Y.;
   Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ApJ...672.1237L
Altcode:
  Observations of very quiet Sun using the Solar Optical
  Telescope/Spectro-Polarimeter (SOT/SP) aboard the Hinode spacecraft
  reveal that the quiet internetwork regions are pervaded by horizontal
  magnetic flux. The spatial average horizontal apparent flux density
  derived from wavelength-integrated measures of Zeeman-induced linear
  polarization is B<SUP>T</SUP><SUB>app</SUB> = 55 Mx cm <SUP>-2</SUP>, as
  compared to the corresponding average vertical apparent flux density of
  | B<SUP>L</SUP><SUB>app</SUB>| = 11 Mx cm <SUP>-2</SUP>. Distributions
  of apparent flux density are presented. Magnetic fields are organized on
  mesogranular scales, with both horizontal and vertical fields showing
  "voids" of reduced flux density of a few granules spatial extent. The
  vertical fields are concentrated in the intergranular lanes, whereas the
  stronger horizontal fields are somewhat separated spatially from the
  vertical fields and occur most commonly at the edges of the bright
  granules. High-S/N observations from disk center to the limb help
  to constrain possible causes of the apparent imbalance between |
  B<SUP>L</SUP><SUB>app</SUB>| and B<SUP>T</SUP><SUB>app</SUB>, with
  unresolved structures of linear dimension on the surface smaller by at
  least a factor of 2 relative to the SOT/SP angular resolution being one
  likely cause of this discrepancy. Other scenarios for explaining this
  imbalance are discussed. The horizontal fields are likely the source of
  the "seething" fields of the quiet Sun discovered by Harvey et al. The
  horizontal fields may also contribute to the "hidden" turbulent flux
  suggested by studies involving Hanle effect depolarization of scattered
  radiation.

Title: Hinode Observations of Flux Emergence in Quiet and Active
    Regions
Authors: Lites, B. W.; Centeno, R.; Kubo, M.; Socas-Navarro, H. Berger,
   T.; Frank, Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.;
   Katsukawa, Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2008ASPC..383...71L
Altcode:
  We review briefly the observational understanding of emergence of
  flux in both the quiet Sun and active regions in the light of first
  results from the joint Japan/US/UK Hinode mission. That spacecraft
  is now providing us with our first continuous, high resolution
  measurements of the photospheric vector magnetic field, along with
  high resolution observations of the thermal and dynamic properties
  of the chromosphere and corona. This review is intended to present a
  few very early results and to highlight the potential for discovery
  offered by this extraordinary new mission. The discovery of ubiquitous
  horizontal magnetic flux in the quiet internetwork regions is presented.

Title: Mangetic field properties at the footpoints of solar
    microflares (active-region transient brightenings)
Authors: Shimizu, T.; Kano, R.; Katsukawa, Y.; Kubo, M.; Deluca, E.;
   Ichimoto, K.; Lites, B.; Nagata, S.; Sakao, T.; Shine, R.; Suematsu,
   Y.; Tarbell, T.; Title, A.; Tsuneta, S.
Bibcode: 2007AGUFMSH52C..06S
Altcode:
  Solar active regions produce numerous numbers of small-scale explosive
  energy releases, i.e., microflares, which are captured by imaging
  observations in soft X-rays as transient brightenings of small-scale
  coronal loops. Thanks to advanced performance of X-Ray Telescope (XRT)
  onboard the Hinode satellite, we can investigate finer structure
  of the brightening X-ray sources in more details than we did with
  Yohkoh data. One of important questions on microflares is what causes
  microflares. The simultaneous visible-light observations by the Solar
  Optical Telescope (SOT) allow us to explore magnetic activities
  and magnetic field configuration at the photospheric footpoints
  of brightening loops, giving key observations to investigate the
  question. For our investigations of corona-photosphere magnetic
  coupling, we have established co-alignment between SOT and XRT
  with accuracy better than 1 arcsec (Shimizu et al. 2007, PASJ in
  press). It turns out that Ca II H observations are very useful
  to identify the exact positions of footpoints of X-ray transient
  brightening loops. Small "Kernels" are sometimes observed in Ca II H
  and they may be signature of highly accelerated non-thermal particles
  impinging on chromosphere. As already shown in Shimizu et al.(2002),
  frequent transient brightenings are observed at the locations where
  emerging activities are on going. However, another type of brightening
  triggering mechanism should exist to explain some observed multiple-loop
  brightenings. In the multiple-loop brightenings, multiple loops are
  magnetically in parallel with each other and no apparent magnetic
  activities, such as emerging and canceling, are observed at and near
  the footpoints. This paper will present SOT observations of some
  microflares observed with XRT.

Title: Small-Scale Jetlike Features in Penumbral Chromospheres
Authors: Katsukawa, Y.; Berger, T. E.; Ichimoto, K.; Lites, B. W.;
   Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.;
   Title, A. M.; Tsuneta, S.
Bibcode: 2007Sci...318.1594K
Altcode:
  We observed fine-scale jetlike features, referred to as penumbral
  microjets, in chromospheres of sunspot penumbrae. The microjets
  were identified in image sequences of a sunspot taken through a Ca II
  H-line filter on the Solar Optical Telescope on board the Japanese solar
  physics satellite Hinode. The microjets’ small width of 400 kilometers
  and short duration of less than 1 minute make them difficult to identify
  in existing observations. The microjets are possibly caused by magnetic
  reconnection in the complex magnetic configuration in penumbrae and
  have the potential to heat the corona above a sunspot.

Title: Chromospheric Alfvénic Waves Strong Enough to Power the
    Solar Wind
Authors: De Pontieu, B.; McIntosh, S. W.; Carlsson, M.; Hansteen,
   V. H.; Tarbell, T. D.; Schrijver, C. J.; Title, A. M.; Shine, R. A.;
   Tsuneta, S.; Katsukawa, Y.; Ichimoto, K.; Suematsu, Y.; Shimizu, T.;
   Nagata, S.
Bibcode: 2007Sci...318.1574D
Altcode:
  Alfvén waves have been invoked as a possible mechanism for the heating
  of the Sun's outer atmosphere, or corona, to millions of degrees and
  for the acceleration of the solar wind to hundreds of kilometers per
  second. However, Alfvén waves of sufficient strength have not been
  unambiguously observed in the solar atmosphere. We used images of
  high temporal and spatial resolution obtained with the Solar Optical
  Telescope onboard the Japanese Hinode satellite to reveal that the
  chromosphere, the region sandwiched between the solar surface and
  the corona, is permeated by Alfvén waves with strong amplitudes on
  the order of 10 to 25 kilometers per second and periods of 100 to
  500 seconds. Estimates of the energy flux carried by these waves and
  comparisons with advanced radiative magnetohydrodynamic simulations
  indicate that such Alfvén waves are energetic enough to accelerate
  the solar wind and possibly to heat the quiet corona.

Title: Magnetic and Doppler Observations of the Photosphere and Low
    Chromosphere with the Solar Optical Telescope on Hinode
Authors: Tarbell, T. D.; Lites, B. W.; Shine, R. A.; Ichimoto, K.
Bibcode: 2007AGUFMSH53A1064T
Altcode:
  We present magnetic field and Doppler shift measurements in the Mg
  I b line at 517.3 nm obtained with the Solar Optical Telescope's
  Narrowband Filter Imager on Hinode. The line core forms in the low
  chromosphere, and the wings where the measurements are made probably
  form around the temperature minimum. Stokes IQUV images in the red and
  blue wings are combined to make movies of longitudinal magnetograms
  and Dopplergrams. The direction of the transverse field component is
  also measurable in strong field concentrations. These are compared
  with very accurate photospheric magnetic measurements in Fe I 630.2 nm
  from the Spectro-Polarimeter. This comparison calibrates the filter
  longitudinal magnetograms in flux density and shows changes in field
  geometry with height. The Doppler measurements are calibrated using
  wavelength scans through the Mg line profile. A number of emerging and
  canceling magnetic features were observed in AR 10961 during its disk
  passage in late June and early July. Since these were made during the
  Hinode eclipse season, the observations have somewhat lower spatial
  resolution than usual (0.32 arcsecond pixels), but the uniformity
  and sensitivity are excellent. Intermittent upflows seen between
  canceling magnetic features are interpreted in terms of reconnection
  outflows. Strong, persistent downflows are seen adjacent to but not
  on flux concentrations outside of sunspots and pores. In the sunspot,
  running penumbral waves are clearly visible, and steady downflows are
  observed over the light bridges. Hinode is a Japanese mission developed
  and launched by ISAS/ JAXA, with NAOJ as domestic partner and NASA and
  STFC (UK) as international partners. It is operated by these agencies
  in cooperation with ESA and NSC (Norway).

Title: Chromospheric Anemone Jets as Evidence of Ubiquitous
    Reconnection
Authors: Shibata, Kazunari; Nakamura, Tahei; Matsumoto, Takuma; Otsuji,
   Kenichi; Okamoto, Takenori J.; Nishizuka, Naoto; Kawate, Tomoko;
   Watanabe, Hiroko; Nagata, Shin'ichi; UeNo, Satoru; Kitai, Reizaburo;
   Nozawa, Satoshi; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi;
   Shimizu, Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.; Berger,
   Thomas E.; Lites, Bruce W.; Shine, Richard A.; Title, Alan M.
Bibcode: 2007Sci...318.1591S
Altcode: 2008arXiv0810.3974S
  The heating of the solar chromosphere and corona is a long-standing
  puzzle in solar physics. Hinode observations show the ubiquitous
  presence of chromospheric anemone jets outside sunspots in active
  regions. They are typically 3 to 7 arc seconds = 2000 to 5000 kilometers
  long and 0.2 to 0.4 arc second = 150 to 300 kilometers wide, and their
  velocity is 10 to 20 kilometers per second. These small jets have an
  inverted Y-shape, similar to the shape of x-ray anemone jets in the
  corona. These features imply that magnetic reconnection similar to that
  in the corona is occurring at a much smaller spatial scale throughout
  the chromosphere and suggest that the heating of the solar chromosphere
  and corona may be related to small-scale ubiquitous reconnection.

Title: Twisting Motions of Sunspot Penumbral Filaments
Authors: Ichimoto, K.; Suematsu, Y.; Tsuneta, S.; Katsukawa, Y.;
   Shimizu, T.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Lites, B. W.;
   Kubo, M.; Nagata, S.
Bibcode: 2007Sci...318.1597I
Altcode:
  The penumbra of a sunspot is composed of numerous thin, radially
  extended, bright and dark filaments carrying outward gas flows
  (the Evershed flow). Using high-resolution images obtained by the
  Solar Optical Telescope aboard the solar physics satellite Hinode, we
  discovered a number of penumbral bright filaments revealing twisting
  motions about their axes. These twisting motions are observed only
  in penumbrae located in the direction perpendicular to the symmetry
  line connecting the sunspot center and the solar disk center, and
  the direction of the twist (that is, lateral motions of intensity
  fluctuation across filaments) is always from limb side to disk-center
  side. Thus, the twisting feature is not an actual twist or turn of
  filaments but a manifestation of dynamics of penumbral filaments with
  three-dimensional radiative transfer effects.

Title: Hinode SOT observations of plume upflows and cascading
    downflows in quiescent solar prominences
Authors: Berger, T.; Shine, R.; Slater, G.; Tarbell, T.; Title, A.;
   Lites, B.; Tsuneta, S.; Okamoto, T. J.; Ichimoto, K.; Katsukawa, Y.;
   Sekii, T.; Suematsu, Y.; Shimizu, T.
Bibcode: 2007AGUFMSH53A1065B
Altcode:
  We present several Hinode SOT filtergram movies of quiescent solar
  prominences that show newly discovered "plume-like" upflows and
  cascading "waterfall-like" downflows that persist for the entire
  multi-hour duration of the observations. The flow speeds are on the
  order of 10 km/sec with typical widths of 400-700 km. Preliminary
  calculations show that if the upflows are buoyancy driven, the
  associated thermal perturbation is on the order of 10,000 K, sufficient
  to explain the dark appearance of the upflows in the interference
  filter passbands. In addition we observe rotational vortices and
  body oscillations within the prominences. These new observations
  challenge current magnetostatic models of solar prominences by showing
  that prominence plasmas are in constant motion, often in directions
  perpendicular to the magnetic field lines proposed by the models. TRACE,
  Hinode/EIS, and Hinode/XRT observations are used to investigate the
  differential topology of the flows across temperature regimes.

Title: On the Chromospheric Micro-jets Associated with the Penumbral
    Filaments
Authors: Ryutova, M.; Berger, T.; Tarbell, T.; Frank, Z.; Title, A.
Bibcode: 2007AGUFMSH22A0843R
Altcode:
  We present observations of sunspot penumbrae obtained during the disk
  passage of AR 10923 (November 10--20, 2006) with the Solar Optical
  Telescope (SOT) on the Hinode satellite. Co-aligned multi-hour movies
  taken simultaneously in several wavelengths show fine-scale dynamics
  at the sub-arcsecond level. The dynamics include helical flows along
  penumbral filaments, branching of filaments, and penumbral "micro-jets"
  recently described by Katsukawa et al. (AAS 210, 94.13). We present
  quantitative analyzes of the penumbral jets and interpret them relative
  to our recent model of penumbral filaments (Ryutova, Berger and Title,
  2007, in "Collective phenomena in macroscopic systems", Ed. G. Bertin,
  et al., World Scientific) to show that the jets are the result of
  magnetic reconnection of the helical field lines in neighboring
  non-collinear filaments.

Title: Coronal Transverse Magnetohydrodynamic Waves in a Solar
    Prominence
Authors: Okamoto, T. J.; Tsuneta, S.; Berger, T. E.; Ichimoto, K.;
   Katsukawa, Y.; Lites, B. W.; Nagata, S.; Shibata, K.; Shimizu, T.;
   Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title, A. M.
Bibcode: 2007Sci...318.1577O
Altcode: 2008arXiv0801.1958O
  Solar prominences are cool 10<SUP>4</SUP> kelvin plasma clouds
  supported in the surrounding 10<SUP>6</SUP> kelvin coronal plasma by
  as-yet-undetermined mechanisms. Observations from Hinode show fine-scale
  threadlike structures oscillating in the plane of the sky with periods
  of several minutes. We suggest that these represent Alfvén waves
  propagating on coronal magnetic field lines and that these may play
  a role in heating the corona.

Title: Photospheric Magnetic Flux Emergence: A comparative study
    between Hinode/SOT Observations and MHD simulations
Authors: Cheung, M. C.; Schüssler, M.; Moreno-Insertis, F.; Tarbell,
   T. D.
Bibcode: 2007AGUFMSH53A1073C
Altcode:
  With high angular resolution, high temporal cadence and a stable
  point spread function, the Solar Optical Telescope (SOT) onboard the
  Hinode satellite is the ideal instrument for the study of magnetic
  flux emergence and its manifestations on the solar surface. In this
  presentation, we focus on the development of ephemeral regions and
  small active regions. In many instances, SOT has been able to capture
  the entire emergence process from beginning to end: i.e. from the
  initial stages of flux appearance in granule interiors, through the
  intermediate stages of G-band bright point formation, and finally
  to the coalescence of small vertical flux elements to form pores. To
  investigate the physics of the flux emergence process, we performed
  3D numerical MHD simulations with the MURaM code. The models are able
  to reproduce, and help us explain, various observational signatures
  of magnetic flux emergence.

Title: Quiet-Sun Internetwork Magnetic Fields from the Inversion of
    Hinode Measurements
Authors: Orozco Suárez, D.; Bellot Rubio, L. R.; del Toro Iniesta,
   J. C.; Tsuneta, S.; Lites, B. W.; Ichimoto, K.; Katsukawa, Y.; Nagata,
   S.; Shimizu, T.; Shine, R. A.; Suematsu, Y.; Tarbell, T. D.; Title,
   A. M.
Bibcode: 2007ApJ...670L..61O
Altcode: 2007arXiv0710.1405O
  We analyze Fe I 630 nm observations of the quiet Sun at disk center
  taken with the spectropolarimeter of the Solar Optical Telescope aboard
  the Hinode satellite. A significant fraction of the scanned area,
  including granules, turns out to be covered by magnetic fields. We
  derive field strength and inclination probability density functions from
  a Milne-Eddington inversion of the observed Stokes profiles. They show
  that the internetwork consists of very inclined, hG fields. As expected,
  network areas exhibit a predominance of kG field concentrations. The
  high spatial resolution of Hinode's spectropolarimetric measurements
  brings to an agreement the results obtained from the analysis of
  visible and near-infrared lines.

Title: Center-to-Limb Variation of Stokes V Asymmetries in Solar
    Pores Observed with the Hinode Spectro-Polarimeter
Authors: Morinaga, Shuji; Nagata, Shin'ichi; Ichimoto, Kiyoshi;
   Suematsu, Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimizu,
   Toshifumi; Shine, Richard A.; Tarbell, Theodore D.; Title, Alan M.;
   Lites, Bruce; Kubo, Masahito; Sakurai, Takashi
Bibcode: 2007PASJ...59S.613M
Altcode:
  Here we present spectro-polarimetric measurements of several pores
  and the surrounding regions taken with the Solar Optical Telescope
  aboard Hinode at various viewing angles. We analyzed the Stokes V
  area asymmetry, and confirmed that it is depressed at the center of
  the pores, while it shows large positive values (a blue lobe larger
  than a red lobe) in the surrounding area; this is consistent with a
  previous report. In addition to this ring of positive asymmetry, we
  found regions of alternating positive and negative area asymmetries
  when weak V regions were observed near the solar limb. The positive
  asymmetry occurs on the disk-center side and the negative asymmetry
  on the limb side of the magnetic concentrations. These center-to-limb
  variations of the Stokes V area asymmetry can be interpreted as being
  a systematic inflow of plasma into the magnetic concentrations from
  their surroundings.

Title: Initial Results on Line-of-Sight Field Calibrations of SP/NFI
    Data Taken by SOT/Hinode
Authors: Chae, Jongchul; Moon, Yong-Jae; Park, Young-Deuk; Ichimoto,
   Kiyoshi; Sakurai, Takashi; Suematsu, Yoshinori; Tsuneta, Saku;
   Katsukawa, Yukio; Shimizu, Toshifumi; Shine, Richard A.; Tarbell,
   Theodore D.; Title, Alan M.; Lites, Bruce; Kubo, Masahito; Nagata,
   Shin'ichi; Yokoyama, Takaaki
Bibcode: 2007PASJ...59S.619C
Altcode:
  We present initial results on the line-of-sight field calibration
  of the two kinds of Stokes I and V data taken by the Solar Optical
  Telescope on the satellite Hinode: spectral profiles of Stokes I and V
  parameters recorded on the Spectro-polarimeter (SP), and monochromatic
  images of the same parameters recorded on the Narrow-band Filter Imager
  (NFI). By applying the center-of-gravity method to the SP data of
  AR10930 taken on 2006 December 11, we determined the line-of-sight field
  at every location in the active region. As a result, we found that the
  line-of-sight field strength ranges up to 2kG in plages, even without
  taking into account the filling factor, and up to 3.5kG or higher values
  inside the umbra of the major sunspot. We calibrated the NFI data in
  reference to the field determined from the SP data. In regions outside
  the sunspots and the penumbral regions, we adopted a linear relation,
  B<SUB>||</SUB> = βV / I, between the circular polarization, V / I,
  and the line-of-sight field strength, B<SUB>||</SUB>, and obtained β =
  23.5kG in regions outside the sunspots, and β = 12.0kG in penumbral
  regions. In umbral regions of sunspots, a first-order polynomial was
  adopted to model the reversal of the polarization signal over the
  field strength.

Title: Response of the Solar Atmosphere to Magnetic Flux Emergence
    from Hinode Observations
Authors: Li, Hui; Sakurai, Takashi; Ichimito, Kiyoshi; Suematsu,
   Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimizu, Toshifumi; Shine,
   Richard A.; Tarbell, Theodore D.; Title, Alan M.; Lites, Bruce; Kubo,
   Masahito; Nagata, Shin'ichi; Kotoku, Jun; Shibasaki, Kiyoto; Saar,
   Steven H.; Bobra, Monica
Bibcode: 2007PASJ...59S.643L
Altcode:
  No abstract at ADS

Title: Initial Helioseismic Observations by Hinode/SOT
Authors: Sekii, Takashi; Kosovichev, Alexander G.; Zhao, Junwei;
   Tsuneta, Saku; Shibahashi, Hiromoto; Berger, Thomas E.; Ichimoto,
   Kiyoshi; Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu,
   Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell, Theodore
   D.; Title, Alan M.
Bibcode: 2007PASJ...59S.637S
Altcode: 2007arXiv0709.1806S
  Results from initial helioseismic observations by the Solar Optical
  Telescope on-board Hinode are reported. It has been demonstrated
  that intensity oscillation data from the Broadband Filter Imager
  can be used for various helioseismic analyses. The k - ω power
  spectra, as well as the corresponding time-distance cross-correlation
  function, which promise high-resolution time-distance analysis below
  the 6-Mm travelling distance, were obtained for G-band and CaII-H
  data. Subsurface supergranular patterns were observed from our first
  time-distance analysis. The results show that the solar oscillation
  spectrum is extended to much higher frequencies and wavenumbers, and
  the time-distance diagram is extended to much shorter travel distances
  and times than were observed before, thus revealing great potential
  for high-resolution helioseismic observations from Hinode.

Title: Hinode Observations of Horizontal Quiet Sun Magnetic Flux
    and the ``Hidden Turbulent Magnetic Flux''
Authors: Lites, Bruce; Socas-Navarro, Hector; Kubo, Masahito; Berger,
   Thomas; Frank, Zoe; Shine, Richard A.; Tarbell, Theodore D.; Title,
   Alan M.; Ichimoto, Kiyoshi; Katsukawa, Yukio; Tsuneta, Saku; Suematsu,
   Yoshinori; Shimizu, Toshifumi
Bibcode: 2007PASJ...59S.571L
Altcode:
  We present observations of magnetic fields of the very quiet Sun
  near disk center using the Spectro-Polarimeter of the Solar Optical
  Telescope aboard the Hinode satellite. These observations reveal for
  the first time the ubiquitous presence of horizontal magnetic fields in
  the internetwork regions. The horizontal fields are spatially distinct
  from the vertical fields, demonstrating that they are not arising mainly
  from buffeting of vertical flux tubes by the granular convection. The
  horizontal component has an average ``apparent flux density'' of
  55Mxcm<SUP>-2</SUP> (assuming the horizontal field structures are
  spatially resolved), in contrast to the average apparent vertical flux
  density of 11Mxcm<SUP>-2</SUP>. The vertical fields reside mainly in
  the intergranular lanes, whereas the horizontal fields occur mainly
  over the bright granules, with a preference to be near the outside
  edge of the bright granules. The large apparent imbalance of vertical
  and horizontal flux densities is discussed, and several scenarios are
  presented to explain this imbalance.

Title: Strategy for the Inversion of Hinode Spectropolarimetric
    Measurements in the Quiet Sun
Authors: Orozco Suárez, David; Bellot Rubio, Luis R.; Del Toro
   Iniesta, Jose Carlos; Tsuneta, Saku; Lites, Bruce; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
   Richard A.; Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.
Bibcode: 2007PASJ...59S.837O
Altcode: 2007arXiv0709.2033O
  In this paper we propose an inversion strategy for the analysis of
  spectropolarimetric measurements taken by Hinode in the quiet Sun. The
  Spectro-Polarimeter of the Solar Optical Telescope aboard Hinode records
  the Stokes spectra of the FeI line pair at 630.2nm with unprecendented
  angular resolution, high spectral resolution, and high sensitivity. We
  discuss the need to consider a local stray-light contamination to
  account for the effects of telescope diffraction. The strategy is
  applied to observations of a wide quiet Sun area at disk center. Using
  these data we examine the influence of noise and initial guess models
  in the inversion results. Our analysis yields the distributions of
  magnetic field strengths and stray-light factors. They show that quiet
  Sun internetwork regions consist mainly of hG fields with stray-light
  contamination of about 0.8.

Title: Hinode Calibration for Precise Image Co-Alignment between
    SOT and XRT (2006 November-2007 April)
Authors: Shimizu, Toshifumi; Katsukawa, Yukio; Matsuzaki, Keiichi;
   Ichimoto, Kiyoshi; Kano, Ryohei; Deluca, Edward E.; Lundquist,
   Loraine L.; Weber, Mark; Tarbell, Theodore D.; Shine, Richard A.;
   Sôma, Mitsuru; Tsuneta, Saku; Sakao, Taro; Minesugi, Kenji
Bibcode: 2007PASJ...59S.845S
Altcode: 2007arXiv0709.4098S
  To understand the physical mechanisms for activity and heating in
  the solar atmosphere, the magnetic coupling from the photosphere
  to the corona is an important piece of information from the Hinode
  observations, and therefore precise positional alignment is required
  among the data acquired by different telescopes. The Hinode spacecraft
  and its onboard telescopes were developed to allow us to investigate
  magnetic coupling with co-alignment accuracy better than 1". Using
  the Mercury transit observed on 2006 November 8 and co-alignment
  measurements regularly performed on a weekly basis, we have determined
  the information necessary for precise image co-alignment, and have
  confirmed that co-alignment better than 1" can be realized between
  Solar Optical Telescope (SOT) and X-Ray Telescope (XRT) with our
  baseline co-alignment method. This paper presents results from the
  calibration for precise co-alignment of CCD images from SOT and XRT.

Title: Penumbral Dynamics and its Manifestation in the Overlying
    Chromosphere
Authors: Ryutova, Margarita; Berger, Thomas; Tarbell, Theodor; Frank,
   Zoe; Title, Alan
Bibcode: 2007APS..DPPYP8056R
Altcode:
  Mature sunspots are usually surrounded by penumbra - a dense
  conglomerate of a random interlaced flux tubes with varying
  inclinations. High resolution observations show a fine sub-structure
  of penumbral filaments and new regularities in their dynamics. These
  regularities fit well our recent model of penumbra based on cascading
  reconnection events occurring in the system of non-collinear flux
  tubes. Each act of reconnection generates twist in the reconnected
  filaments and facilitates the onset of a screw pinch instability,
  consistent with the observations showing that individual filaments
  are cylindrical helices with a pitch/radius ratio providing their
  stability. In addition, the post-reconnection products produce a
  sling-shot effect that generates oblique shocks and leads to appearence
  of a lateral jets. Here we report high resolution (120-180 km) high
  cadence (15-30 sec) observations taken with the Solar Optical Telescope
  (SOT) on the Hinode satellite. Co-aligned multi-hour movies taken
  simultaneously in several wavelengths show detailed behavior of penumbra
  filaments and their effect on the overlying chromosphere. We confirm
  the ubiquitous nature of penumbral micro-jets recently discovered by
  SOT instrument (Katsukawa et al. 2007, AAS 210, 94.13), and present
  quantitative analysis of chromospheric jets based on our recent model
  of penumbra.

Title: Hinode Observations of a Vector Magnetic Field Change
    Associated with a Flare on 2006 December 13
Authors: Kubo, Masahito; Yokoyama, Takaaki; Katsukawa, Yukio; Lites,
   Bruce; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Shimizu,
   Toshifumi; Nagata, Shin'ichi; Tarbell, Theodore D.; Shine, Richard A.;
   Title, Alan M.; Elmore David
Bibcode: 2007PASJ...59S.779K
Altcode: 2007arXiv0709.2397K
  Continuous observations of the flare productive active region 10930
  were successfully carried out with the Solar Optical Telescope aboard
  the Hinode spacecraft during 2006 December 6 to 19. We focused on the
  evolution of photospheric magnetic fields in this active region, and the
  magnetic field properties at the site of the X3.4 class flare, using
  a time series of vector field maps with high spatial resolution. The
  X3.4 class flare occurred on 2006 December 13 at the apparent
  collision site between the large, opposite polarity umbrae. Elongated
  magnetic structures with alternatingly positive and negative polarities
  resulting from flux emergence appeared one day before the flare in the
  collision site penumbra. Subsequently, the polarity inversion line
  at the collision site became very complicated. The number of bright
  loops in CaII H increased during the formation of these elongated
  magnetic structures. Flare ribbons and bright loops evolved along
  the polarity inversion line and one footpoint of the bright loop was
  located in a region having a large departure of the field azimuth angle
  with respect to its surroundings. SOT observations with high spatial
  resolution and high polarization precision revealed temporal change in
  the fine structure of magnetic fields at the flare site: some parts of
  the complicated polarity inversion line then disappeared, and in those
  regions the azimuth angle of the photospheric magnetic field changed by
  about 90°, becoming more spatially uniform within the collision site.

Title: The Analysis of Penumbral Fine Structure Using an Advanced
    Inversion Technique
Authors: Jurcák, Jan; Bellot Rubio, Luis; Ichimoto, Kiyoshi;
   Katsukawa, Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi;
   Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.; Tsuneta,
   Saku
Bibcode: 2007PASJ...59S.601J
Altcode: 2007arXiv0707.1560J
  We present a method to study the penumbral fine structure using data
  obtained by the spectropolarimeter on board Hinode. For the first
  time, the penumbral filaments can be considered as being resolved in
  spectropolarimetric measurements. This enables us to use inversion
  codes with only one-component model atmospheres, and thus to assign
  the obtained stratifications of the plasma parameters directly to the
  penumbral fine structure. This approach was applied to the limb-side
  part of the penumbra in the active region NOAA10923. Preliminary results
  show a clear dependence of the plasma parameters on the continuum
  intensity in the inner penumbra, i.e., a weaker and horizontal magnetic
  field along with an increased line-of-sight velocity are found in the
  low layers of the bright filaments. The results in the mid penumbra
  are ambiguous, and future analyses are necessary to unveil the magnetic
  field structure and other plasma parameters there.

Title: Fine-Scale Structures of the Evershed Effect Observed by the
    Solar Optical Telescope aboard Hinode
Authors: Ichimoto, Kiyoshi; Shine, Richard A.; Lites, Bruce; Kubo,
   Masahito; Shimizu, Toshifumi; Suematsu, Yoshinori; Tsuneta, Saku;
   Katsukawa, Yukio; Tarbell, Theodore D.; Title, Alan M.; Nagata,
   Shin'ichi; Yokoyama, Takaaki; Shimojo, Masumi
Bibcode: 2007PASJ...59S.593I
Altcode:
  The small-scale structure of the Evershed effect is being studied
  using data obtained by the Spectropolarimeter and the Broadband Filter
  Imager of the Solar Optical Telescope aboard Hinode. We find that the
  Evershed flow starts at the leading edge of inwardly migrating bright
  penumbral grains, and turns to nearly a horizontal flow preferentially
  in the dark lanes of the penumbra. A number of small elongated regions
  that have an upward motion of ∼ 1kms<SUP>-1</SUP> are found in the
  deep photosphere distributed over the penumbra. They are cospatial
  with bright grains and have relatively horizontal magnetic fields. A
  number of patches having a strong downward motion associated with the
  opposite magnetic polarity from the sunspot are also found in the mid
  and outer penumbra. They could be identified as foot points of the
  Evershed flow channels, though the identification of individual pairs
  is not straightforward. Our results provide strong support for some
  recent findings from ground-based high-resolution observations, and
  are in general agreement with the well-known picture of the uncombed
  structure of the penumbra, in which the penumbrae consist of rising
  flux tubes carrying nearly horizontal Evershed flows embedded in more
  vertical background magnetic fields.

Title: Flare Ribbons Observed with G-band and FeI 6302Å, Filters
    of the Solar Optical Telescope on Board Hinode
Authors: Isobe, Hiroaki; Kubo, Masahito; Minoshima, Takashi; Ichimoto,
   Kiyoshi; Katsukawa, Yukio; Tarbell, Theodore D.; Tsuneta, Saku; Berger,
   Thomas E.; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
   Richard A.; Suematsu, Yoshinori; Title, Alan M.
Bibcode: 2007PASJ...59S.807I
Altcode: 2007arXiv0711.3946I
  The Solar Optical Telescope (SOT) on board the Hinode satellite observed
  an X3.4 class flare on 2006 December 13. A typical two-ribbon structure
  was observed, not only in the chromospheric CaII H line, but also in
  the G-band and FeI 6302Å line. The high-resolution, seeing-free images
  achieved by SOT revealed, for the first time, sub-arcsec fine structures
  of the ``white light'' flare. The G-band flare ribbons on sunspot
  umbrae showed a sharp leading edge, followed by a diffuse inside,
  as well as a previously known core-halo structure. The underlying
  structures, such as umbral dots, penumbral filaments, and granules,
  were visible in the flare ribbons. Assuming that the sharp leading
  edge was directly heated by a particle beam and the diffuse parts were
  heated by radiative back-warming, we estimated the depth of the diffuse
  flare emission using an intensity profile of the flare ribbon. We found
  that the depth of the diffuse emission was about 100km or less from
  the height of the source of radiative back-warming. The flare ribbons
  were also visible in the Stokes-V images of FeI 6302Å, as a transient
  polarity reversal. This is probably related to a ``magnetic transient''
  reported in the literature. The intensity increase in Stokes-I images
  indicates that the FeI 6302Å line was significantly deformed by the
  flare, which may cause such a magnetic transient.

Title: Small-Scale Magnetic-Flux Emergence Observed with Hinode
    Solar Optical Telescope
Authors: Otsuji, Kenichi; Shibata, Kazunari; Kitai, Reizaburo; Ueno,
   Satoru; Nagata, Shin'ichi; Matsumoto, Takuma; Nakamura, Tahei;
   Watanabe, Hiroko; Tsuneta, Saku; Suematsu, Yoshinori; Ichimoto,
   Kiyoshi; Shimizu, Toshifumi; Katsukawa, Yukio; Tarbell, Theodore D.;
   Lites, Bruce; Shine, Richard A.; Title Alan M.
Bibcode: 2007PASJ...59S.649O
Altcode: 2007arXiv0709.3207O
  We observed small-scale magnetic-flux emergence in a sunspot moat region
  by the Solar Optical Telescope (SOT) aboard the Hinode satellite. We
  analyzed filtergram images observed at wavelengths of Fe 6302Å, G band,
  and CaII H. In Stokes I images of Fe 6302Å, emerging magnetic flux was
  recognized as dark lanes. In the G band, they showed to be their shapes
  almost the same as in Stokes I images. These magnetic fluxes appeared
  as dark filaments in CaII H images. Stokes V images of Fe 6302Å showed
  pairs of opposite polarities at footpoints of each filament. These
  magnetic concentrations were identified to correspond to bright points
  in G band/CaII H images. From an analysis of time-sliced diagrams, we
  derived the following properties of emerging flux, which are consistent
  with those of previous studies: (1) Two footpoints separate each other
  at a speed of 4.2kms<SUP>-1</SUP> during the initial phase of evolution,
  and decrease to about 1kms<SUP>-1</SUP> 10minutes later. (2) CaII H
  filaments appear almost simultaneously with the formation of dark lanes
  in Stokes I in an observational cadence of 2minutes. (3) The lifetime
  of the dark lanes in the Stokes I and G band is 8minutes, while that
  of Ca filament is 12minutes. An interesting phenomena was observed,
  that an emerging flux tube expanded laterally in the photosphere with a
  speed of 3.8kms<SUP>-1</SUP>. A discussion on the horizontal expansion
  of the flux tube is given with refernce to previous simulation studies.

Title: Observations of Sunspot Oscillations in G Band and CaII H
    Line with Solar Optical Telescope on Hinode
Authors: Nagashima, Kaori; Sekii, Takashi; Kosovichev, Alexander G.;
   Shibahashi, Hiromoto; Tsuneta, Saku; Ichimoto, Kiyoshi; Katsukawa,
   Yukio; Lites, Bruce; Nagata, Shin'ichi; Shimizu, Toshifumi; Shine,
   Richard A.; Suematsu, Yoshinori; Tarbell, Theodore D.; Title, Alan M.
Bibcode: 2007PASJ...59S.631N
Altcode: 2007arXiv0709.0569N
  Exploiting high-resolution observations made by the Solar Optical
  Telescope on board Hinode, we investigate the spatial distribution
  of the power spectral density of the oscillatory signal in and around
  the active region NOAA 10935. The G-band data show that in the umbra
  the oscillatory power is suppressed in all frequency ranges. On
  the other hand, in CaII H intensity maps oscillations in the umbra,
  so-called umbral flashes, are clearly seen with the power peaking around
  5.5mHz. The CaII H power distribution shows the enhanced elements with
  the spatial scale of the umbral flashes over most of the umbra, but
  there is a region with suppressed power at the center of the umbra. The
  origin and property of this node-like feature remain unexplained.

Title: Hinode SP Vector Magnetogram of AR10930 and Its
    Cross-Comparison with MDI
Authors: Moon, Yong-Jae; Kim, Yeon-Han; Park, Young-Deuk; Ichimoto,
   Kiyoshi; Sakurai, Takashi; Chae, Jongchul; Cho, Kyung Suk; Bong,
   Suchan; Suematsu, Yoshinori; Tsuneta, Saku; Katsukawa, Yukio; Shimojo,
   Masumi; Shimizu, Toshifumi; Shine, Richard A.; Tarbell, Theodore D.;
   Title, Alan M.; Lites, Bruce; Kubo, Masahito; Nagata, Shin'ichi;
   Yokoyama, Takaaki
Bibcode: 2007PASJ...59S.625M
Altcode:
  We present one Hinode Spectropolarimeter (SP) magnetogram of AR 10930
  that produced several major flares. The inversion from Stokes profiles
  to magnetic field vectors was made using the standard Milne-Eddington
  code. We successfully applied the Uniform Shear Method for resolving
  the 180° ambiguity to the magnetogram. The inversion gave very strong
  magnetic field strengths (near 4500 gauss) for a small portion of area
  in the umbra. Considering that the observed V-profile of 6301.5Å was
  well-fitted as well as a direct estimation of the Zeeman splitting
  results in 4300-4600 gauss, we think that the field strengths
  should not be far from the actual value. A cross-comparison of the
  Hinode SP and SOHO MDI high resolution flux densities shows that the
  MDI flux density could be significantly underestimated by about a
  factor of two. In addition, it has a serious negative correlation
  (the so-called Zeeman saturation effect) with the Hinode SP flux
  density for umbral regions. Finally, we could successfully obtain
  a recalibrated MDI magnetogram that has been corrected for the
  Zeeman saturation effect using not only a pair of MDI intensity and
  magnetogram data simultaneously observed, but also the relationship
  from the cross-comparison between the Hinode SP and MDI flux densities.

Title: Formation Process of a Light Bridge Revealed with the Hinode
    Solar Optical Telescope
Authors: Katsukawa, Yukio; Yokoyama, Takaaki; Berger, Thomas E.;
   Ichimoto, Kiyoshi; Kubo, Masahito; Lites, Bruce; Nagata, Shin'ichi;
   Shimizu, Toshifumi; Shine, Richard A.; Suematsu, Yoshinori; Tarbell,
   Theodore D.; Title, Alan M.; Tsuneta, Saku
Bibcode: 2007PASJ...59S.577K
Altcode: 2007arXiv0709.2527K
  The Solar Optical Telescope (SOT) on-board Hinode successfully and
  continuously observed the formation process of a light bridge in a
  matured sunspot of the NOAA active region 10923 for several days with
  high spatial resolution. During its formation, many umbral dots were
  observed to be emerging from the leading edges of penumbral filaments,
  and rapidly intruding into the umbra. The precursor of the light bridge
  formation was also identified as a relatively slow inward motion of
  the umbral dots, which emerged not near the penumbra, but inside the
  umbra. The spectro-polarimeter on SOT provided physical conditions in
  the photosphere around the umbral dots and the light bridges. We found
  that the light bridges and the umbral dots had significantly weaker
  magnetic fields associated with upflows relative to the core of the
  umbra, which implies that there was hot gas with weak field strength
  penetrating from the subphotosphere to near the visible surface inside
  those structures. There needs to be a mechanism to drive the inward
  motion of the hot gas along the light bridges. We suggest that the
  emergence and the inward motion are triggered by a buoyant penumbral
  flux tube as well as subphotospheric flow crossing the sunspot.

Title: Umbral Fine Structures in Sunspots Observed with Hinode Solar
    Optical Telescope
Authors: Kitai, Reizaburo; Watanabe, Hiroko; Nakamura, Tahei; Otsuji,
   Ken-ichi; Matsumoto, Takuma; UeNo, Satoru; Nagata, Shin'ichi; Shibata,
   Kazunari; Muller, Richard; Ichimoto, Kiyoshi; Tsuneta, Saku; Suematsu,
   Yoshinori; Katsukawa, Yukio; Shimizu, Toshifumi; Tarbell, Theodore D.;
   Shine, Richard A.; Title, Alan M.; Lites, Bruce
Bibcode: 2007PASJ...59S.585K
Altcode: 2007arXiv0711.3266K
  A high resolution imaging observation of a sunspot umbra was made with
  the Hinode Solar Optical Telescope. Filtergrams at wavelengths of the
  blue and green continua were taken during three consecutive days. The
  umbra consisted of a dark core region, several diffuse components,
  and numerous umbral dots. We derived basic properties of umbral dots
  (UDs), especially their temperatures, lifetimes, proper motions,
  spatial distribution, and morphological evolution. The brightness
  of UDs is confirmed to depend on the brightness of their surrounding
  background. Several UDs show fission and fusion. Thanks to the stable
  condition of the space observation, we could for the first time follow
  the temporal behavior of these events. The derived properties of the
  internal structure of the umbra are discussed from the viewpoint of
  magnetoconvection in a strong magnetic field.

Title: On Connecting the Dynamics of the Chromosphere and Transition
    Region with Hinode SOT and EIS
Authors: Hansteen, Viggo H.; de Pontieu, Bart; Carlsson, Mats;
   McIntosh, Scott; Watanabe, Tetsuya; Warren, Harry P.; Harra, Louise K.;
   Hara, Hirohisa; Tarbell, Theodore D.; Shine, Dick; Title, Alan M.;
   Schrijver, Carolus J.; Tsuneta, Saku; Katsukawa, Yukio; Ichimoto,
   Kiyoshi; Suematsu, Yoshinori; Shimizu, Toshifumi
Bibcode: 2007PASJ...59S.699H
Altcode: 2007arXiv0711.0487H
  We use coordinated Hinode SOT/EIS observations that include
  high-resolution magnetograms, chromospheric, and transition region
  (TR) imaging, and TR/coronal spectra in a first test to study how
  the dynamics of the TR are driven by the highly dynamic photospheric
  magnetic fields and the ubiquitous chromospheric waves. Initial
  analysis shows that these connections are quite subtle and require a
  combination of techniques including magnetic field extrapolations,
  frequency-filtered time-series, and comparisons with synthetic
  chromospheric and TR images from advanced 3D numerical simulations. As a
  first result, we find signatures of magnetic flux emergence as well as
  3 and 5mHz wave power above regions of enhanced photospheric magnetic
  field in both chromospheric, transition region, and coronal emission.

Title: Can High Frequency Acoustic Waves Heat the Quiet Sun
    Chromosphere?
Authors: Carlsson, Mats; Hansteen, Viggo H.; de Pontieu, Bart;
   McIntosh, Scott; Tarbell, Theodore D.; Shine, Dick; Tsuneta, Saku;
   Katsukawa, Yukio; Ichimoto, Kiyoshi; Suematsu, Yoshinori; Shimizu,
   Toshifumi; Nagata, Shin'ichi
Bibcode: 2007PASJ...59S.663C
Altcode: 2007arXiv0709.3462C
  We use Hinode/SOT Ca II H-line and blue continuum broadband observations
  to study the presence and power of high frequency acoustic waves at
  high spatial resolution. We find that there is no dominant power at
  small spatial scales; the integrated power using the full resolution of
  Hinode (0.05'' pixels, 0.16'' resolution) is larger than the power in
  the data degraded to 0.5'' pixels (TRACE pixel size) by only a factor
  of 1.2. At 20 mHz the ratio is 1.6. Combining this result with the
  estimates of the acoustic flux based on TRACE data of Fossum &amp;
  Carlsson (2006), we conclude that the total energy flux in acoustic
  waves of frequency 5-40 mHz entering the internetwork chromosphere of
  the quiet Sun is less than 800 W m$^{-2}$, inadequate to balance the
  radiative losses in a static chromosphere by a factor of five.

Title: Formation of Moving Magnetic Features and Penumbral Magnetic
    Fields with Hinode/SOT
Authors: Kubo, Masahito; Ichimoto, Kiyoshi; Shimizu, Toshifumi;
   Tsuneta, Saku; Suematsu, Yoshinori; Katsukawa, Yukio; Nagata,
   Shin'ichi; Tarbell, Theodore D.; Shine, Richard A.; Title, Alan M.;
   Frank, Zoe A.; Lites, Bruce; Elmore, David
Bibcode: 2007PASJ...59S.607K
Altcode: 2007arXiv0709.1853K
  Vector magnetic fields of moving magnetic features (MMFs) were well
  observed with the Solar Optical Telescope (SOT) aboard the Hinode
  satellite. We focused on the evolution of three MMFs with the SOT in
  this study. We found that an MMF having relatively vertical fields
  with the same polarity as the sunspot was detached from the penumbra
  around the granules appearing in the outer penumbra. This suggests
  that granular motions in the outer penumbra are responsible for
  disintegration of the sunspot. Two MMFs with polarity opposite to
  the sunspot are located around the outer edge of horizontal fields
  extending from the penumbra. This is evidence that the MMFs with
  polarity opposite to the sunspot are the prolongation of penumbral
  horizontal fields. Redshifts larger than the sonic velocity in the
  photosphere are detected for some of the MMFs with polarity opposite
  to the sunspot.

Title: A Tale of Two Spicules: The Impact of Spicules on the Magnetic
    Chromosphere
Authors: de Pontieu, Bart; McIntosh, Scott; Hansteen, Viggo H.;
   Carlsson, Mats; Schrijver, Carolus J.; Tarbell, Theodore D.; Title,
   Alan M.; Shine, Richard A.; Suematsu, Yoshinori; Tsuneta, Saku;
   Katsukawa, Yukio; Ichimoto, Kiyoshi; Shimizu, Toshifumi; Nagata,
   Shin'ichi
Bibcode: 2007PASJ...59S.655D
Altcode: 2007arXiv0710.2934D
  We use high-resolution observations of the Sun in CaIIH (3968Å)
  from the Solar Optical Telescope on Hinode to show that there are
  at least two types of spicules that dominate the structure of the
  magnetic solar chromosphere. Both types are tied to the relentless
  magnetoconvective driving in the photosphere, but have very different
  dynamic properties. ``Type-I'' spicules are driven by shock waves
  that form when global oscillations and convective flows leak into
  the upper atmosphere along magnetic field lines on 3--7minute
  timescales. ``Type-II'' spicules are much more dynamic: they form
  rapidly (in ∼ 10s), are very thin (≤ 200 km wide), have lifetimes
  of 10-150s (at any one height), and seem to be rapidly heated to
  (at least) transition region temperatures, sending material through
  the chromosphere at speeds of order 50--150kms<SUP>-1</SUP>. The
  properties of Type II spicules suggest a formation process that is
  a consequence of magnetic reconnection, typically in the vicinity
  of magnetic flux concentrations in plage and network. Both types of
  spicules are observed to carry Alfvén waves with significant amplitudes
  of order 20kms<SUP>-1</SUP>.

Title: Hinode Observations of the Onset Stage of a Solar Filament
    Eruption
Authors: Sterling, Alphonse C.; Moore, Ronald L.; Berger, Thomas
   E.; Bobra, Monica; Davis, John M.; Jibben, Patricia; Kano, Ryohei;
   Lundquist, Loraine L.; Myers, D.; Narukage, Noriyuki; Sakao, Taro;
   Shibasaki, Kiyoto; Shine, Richard A.; Tarbell, Theodore D.; Weber, Mark
Bibcode: 2007PASJ...59S.823S
Altcode:
  We used Hinode X-Ray Telescope (XRT) and Solar Optical Telescope (SOT)
  filtergraph (FG) Stokes-V magnetogram observations, to study the
  early onset of a solar eruption that includes an erupting filament
  that we observe in TRACE EUV images. The filament undergoes a slow
  rise for at least 20min prior to its fast eruption and strong soft
  X-ray (SXR) flaring; such slow rises have been previously reported,
  and the new Hinode data elucidate the physical processes occurring
  during this period. XRT images show that during the slow-rise phase,
  an SXR sigmoid forms from apparent reconnection low in the sheared core
  field traced by the filament, and there is a low-level intensity peak
  in both EUV and SXRs during the slow rise. MDI and SOT FG Stokes-V
  magnetograms show that the pre-eruption filament is along a neutral
  line between opposing-polarity enhanced network cells, and the SOT
  magnetograms show that these opposing fields are flowing together
  and canceling for at least six hours prior to eruption. From the MDI
  data we measured the canceling network fields to be ∼ 40G, and we
  estimated that ∼ 10<SUP>19</SUP> Mx of flux canceled during the
  five hours prior to eruption; this is only ∼ 5% of the total flux
  spanned by the eruption and flare, but apparently its tether-cutting
  cancellation was enough to destabilize the sigmoid field holding the
  filament and resulted in that field's eruption.

Title: What are 'Faculae'?
Authors: Berger, T. E.; Title, A. M.; Tarbell, T.; Rouppe van der
   Voort, L.; Löfdahl, M. G.; Scharmer, G. B.
Bibcode: 2007ASPC..369..103B
Altcode:
  We present very high resolution filtergram and magnetogram observations
  of solar faculae taken at the Swedish 1-meter Solar Telescope (SST)
  on La Palma. Three datasets with average line-of-sight angles of 16,
  34, and 53 degrees are analyzed. The average radial extent of faculae is
  at least 400~km. In addition we find that contrast versus magnetic flux
  density is nearly constant for faculae at a given disk position. These
  facts and the high resolution images and movies reveal that faculae are
  not the interiors of small flux tubes - they are granules seen through
  the transparency caused by groups of magnetic elements or micropores
  ``in front of'' the granules. Previous results which show a strong
  dependency of facular contrast on magnetic flux density were caused
  by bin-averaging of lower resolution data leading to a mixture of
  the signal from bright facular walls and the associated intergranular
  lanes and micropores. The findings are relevant to studies of total
  solar irradiance (TSI) that use facular contrast as a function of disk
  position and magnetic field in order to model the increase in TSI with
  increasing sunspot activity.

Title: Estimate on SOT Light Level in Flight with Throughput
    Measurements in SOT Sun Tests
Authors: Shimizu, T.; Kubo, M.; Tarbell, T. D.; Berger, T. E.;
   Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Miyashita, M.; Noguchi,
   M.; Nakagiri, M.; Tsuneta, S.; Elmore, D. F.; Lites, B. W.
Bibcode: 2007ASPC..369...51S
Altcode:
  The SOT (Solar Optical Telescope, e.g., Shimizu 2004) optical
  system consists of 50cm-aperture optical telescope (OTA) and focal
  plane instrument (FPP). The solar light into the telescope penetrates
  through many optical elements located in OTA and FPP before illuminating
  CCDs. Natural solar light was fed to the integrated SOT in sun tests for
  verifying various optical aspects including the confirmation of photon
  throughput. CCD exposures provide the number of photons accumulated
  in an exposure duration with a clean-room test condition. To estimate
  the absolute intensity of the solar light at the telescope entrance
  in the clean-room test condition, we developed a pinhole-PSD sensor
  for simultaneous monitoring the solar light outside the clean room
  and measured the transmission of light through two flat mirrors of
  the heliostat and clean-room entrance window glass as a function of
  wavelength. The PSD sensor was pre-calibrated with continuous monitoring
  the solar light in a day long under a clear constant sky condition,
  determining the earth atmospheric attenuation and the PSD output for
  the solar light on orbit. These throughput measurements have provided
  an estimate on photon throughput for the SOT flight model. The results
  confirm suitable number of photons without saturation for proper CCD
  exposures in flight.

Title: Performance Characteristics of the Solar-B Spectro-Polarimeter
Authors: Lites, B. W.; Elmore, D. F.; Streander, K. V.; Hoffmann,
   C. M.; Tarbell, T. D.; Title, A. M.; Shine, R. A.; Ichimoto, K.;
   Tsuneta, S.; Shimizu, T.; Suematsu, Y.
Bibcode: 2007ASPC..369...55L
Altcode:
  The Focal Plane Package (FPP) of the Solar Optical Telescope (SOT)
  includes the first precision Spectro-Polarimeter (SP) for solar space
  observations. The FPP/SP will provide high precision measures of
  the vector magnetic field in the solar photosphere. Here we present
  some as-built performance specifications for the entire system of
  telescope + polarimeter. The FPP-SP system represents significant
  gains in several aspects over existing spectro-polarimetric systems;
  notably, angular resolution, polarimetric accuracy, spectral purity,
  and most importantly, temporal continuity of stable, high angular
  resolution. In this short summary of the poster, a few of the
  performance characteristics of the SP are presented.

Title: Calibration of the SOT Polarization
Authors: Ichimoto, K.; Suematsu, Y.; Shimizu, T.; Katsukawa, Y.;
   Noguchi, M.; Nakagiri, M.; Miyashita, M.; Tsuneta, S.; Tarbell, T. D.;
   Shine, R. A.; Hoffmann, C. M.; Cruz, T.; Lites, B. W.; Elmore, D. F.
Bibcode: 2007ASPC..369...39I
Altcode:
  Calibration of SOT polarization property was performed using natural
  sunlight and well calibrated sheet polarizer (linear and circular)
  placed on the entrance of the telescope. The polarimeter response
  matrices were determined for the spectropolarimeter (SP) and the
  narrowband filter imager (NFI), and it is shown that they are well
  behave as predicted and constant over the field of view. The crosstalk
  between I,Q,U,V will be suppressed to the negligible level at the
  photometric accuracy of 10^{-3} after the calibration with the obtained
  matrices. The sensitivity of SOT on linear and circular polarizations
  at each wavelength observed by NFI are also obtained.

Title: Calibration of SOT Dopplergrams
Authors: Katsukawa, Y.; Ichimoto, K.; Sekii, T.; Suematsu, Y.; Tsuneta,
   S.; Shine, R. A.; Tarbell, T. D.
Bibcode: 2007ASPC..369...43K
Altcode:
  Narrow-band Filter Imager on SOT provides Dopplergrams (DGs) which
  are images of Doppler (line- of-sight) velocities. Observations with
  DGs are critically important in studies of photospheric dynamics and
  helioseismology. The primary photospheric line used for DGs is Fe I 5576
  Å which is a line insensitive to Zeeman effect. We made a calibration
  function for the 5576 Å DGs to get actual Doppler velocities from
  velocity indexes using an atlas spectrum and simulated transmission
  profiles for the tunable filter (TF) on SOT. Using data sets taken
  in the natural sun-light test, we quantitatively evaluated accuracy
  of the DGs by comparing the rotational speed of the Sun measured
  with DGs with the expected one. There was a little systematic error
  in the velocity obtained by SOT, but the error was less than 20 %
  of the predicted velocities.

Title: Examinations of the Relative Alignment of the Instruments
    on SOT
Authors: Okamoto, T. J.; Katsukawa, Y.; Shimizu, T.; Ichimoto, K.;
   Suematsu, Y.; Tsuneta, S.; Tarbell, T. D.
Bibcode: 2007ASPC..369...47O
Altcode:
  We report the results of the examination about the relative alignment
  among the instruments on SOT. We employ a test data set obtained in the
  natural sun-light test in May 2005, which has had a grid pattern over
  the entire FOV. SOT has the filtergraph (FG) and the spectro-polarimeter
  (SP). The FG consists of six broadband filter imagers (BFI) and six
  narrowband filter imagers (NFI). We examined the displacements among
  the images taken with different filters to an accuracy of better than
  0.1 pixel corresponding to 0.02''. It is important to know relative
  displacements and plate scales of these instruments for accurate
  alignment of observational data. We note that the values measured in
  our work are relative and it is needed to decide the absolute values
  with another way.

Title: Vector Spectropolarimetry of Dark-cored Penumbral Filaments
    with Hinode
Authors: Bellot Rubio, L. R.; Tsuneta, S.; Ichimoto, K.; Katsukawa,
   Y.; Lites, B. W.; Nagata, S.; Shimizu, T.; Shine, R. A.; Suematsu,
   Y.; Tarbell, T. D.; Title, A. M.; del Toro Iniesta, J. C.
Bibcode: 2007ApJ...668L..91B
Altcode: 2007arXiv0708.2791B
  We present spectropolarimetric measurements of dark-cored penumbral
  filaments taken with Hinode at a resolution of 0.3". Our observations
  demonstrate that dark-cored filaments are more prominent in polarized
  light than in continuum intensity. Far from disk center, the Stokes
  profiles emerging from these structures are very asymmetric and show
  evidence for magnetic fields of different inclinations along the
  line of sight, together with strong Evershed flows of at least 6-7 km
  s<SUP>-1</SUP>. In sunspots closer to disk center, dark-cored penumbral
  filaments exhibit regular Stokes profiles with little asymmetries due
  to the vanishing line-of-sight component of the horizontal Evershed
  flow. An inversion of the observed spectra indicates that the magnetic
  field is weaker and more inclined in the dark cores as compared with
  the surrounding bright structures. This is compatible with the idea
  that dark-cored filaments are the manifestation of flux tubes carrying
  hot Evershed flows.

Title: Emergence of Small-Scale Magnetic Loops in the Quiet-Sun
    Internetwork
Authors: Centeno, R.; Socas-Navarro, H.; Lites, B.; Kubo, M.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Tsuneta, S.;
   Katsukawa, Y.; Suematsu, Y.; Shimizu, T.; Nagata, S.
Bibcode: 2007ApJ...666L.137C
Altcode: 2007arXiv0708.0844C
  We study the emergence of magnetic flux at very small spatial
  scales (less than 2") in the quiet-Sun internetwork. To this aim,
  a time series of spectropolarimetric maps was taken at disk center
  using the instrument SP/SOT on board Hinode. The LTE inversion of
  the full Stokes vector measured in the Fe I 6301 and 6302 Å lines
  allows us to retrieve the magnetic flux and topology in the region
  of study. In the example presented here, the magnetic flux emerges
  within a granular structure. The horizontal magnetic field appears
  prior to any significant amount of vertical field. As time goes on,
  the traces of the horizontal field disappear, while the vertical dipoles
  drift-carried by the plasma motions-toward the surrounding intergranular
  lanes. These events take place within typical granulation timescales.

Title: Data Archive of the Hinode Mission
Authors: Matsuzaki, K.; Shimojo, M.; Tarbell, T. D.; Harra, L. K.;
   Deluca, E. E.
Bibcode: 2007SoPh..243...87M
Altcode:
  All of the Hinode telemetry data are to be reformatted and archived
  in the DARTS system at ISAS and mirrored to data centers around
  the word. The archived data are distributed to users through the
  Internet. This paper gives an overview of the files in the archive,
  including the file formats. All formats are portable and have
  heritage from the previous missions. From the reformatted files, index
  information is created for faster data search. Users can perform queries
  based on information contained in the index. This allows for searches
  to return observations that conform to particular observing conditions.

Title: Chromospheric Micro-jets Discovered Above Sunspot Penumbrae
Authors: Katsukawa, Yukio; Tsuneta, S.; Suematsu, Y.; Ichimoto, K.;
   Shimizu, T.; Kubo, M.; Nagata, S.; Berger, T.; Tarbell, T.; Shine,
   R.; Title, A.
Bibcode: 2007AAS...210.9413K
Altcode: 2007BAAS...39..219K
  The Solar Optical Telescope (SOT) aboard HINODE allows us to observe
  dynamical activities in the solar photosphere and the chromosphere
  with high and stable image quality of 0.2 arcseconds. This superior
  performance of SOT provides new findings of fine-scale transient
  activities occurring in the chromosphere. In this paper, we report
  discovery of fine-scale jet-like phenomena ubiquitously observed
  above sunspot penumbrae. The jets are identified in image sequences
  of a sunspot taken through a Ca II H line filter at 3968A. The Ca II
  H line is sensitive to about 10^4 K plasma in the chromosphere. <P
  />Their length is typically between 3000 and 10000km, and their
  width is smaller than 500km. It is notable that their lifetime
  is shorter than 1 minute. Those small spatial and temporal scale
  possibly makes it difficult to identify the phenomena in existing
  ground-based observations. The jets are easily identified when a
  sunspot is located far from the disk center, and motion of the bright
  features suggests that mass is erupted from lower chromosphere to upper
  atmosphere. Velocities of the motion are estimated to be 50 to 100 km/s
  from their lateral motion of intensity patterns. The velocities are much
  faster than sound speeds in the chromosphere. A possible cause of such
  high-speed jets is magnetic reconnection at the lower chromosphere
  resulted from fluted magnetic configuration in penumbrae which is
  suggested by vector magnetic field measurements in the photosphere.

Title: Hinode Data Calibration For Precise Image Co-alignment:
    XRT vs. SOT
Authors: Shimizu, Toshifumi; DeLuca, E. E.; Lundquist, L.; Sakao,
   T.; Kubo, M.; Narukage, N.; Kano, R.; Katsukawa, Y.; Ichimoto, K.;
   Suematsu, Y.; Tsuneta, S.; Tarbell, T.; Shine, D.; Hinode Team
Bibcode: 2007AAS...210.9417S
Altcode: 2007BAAS...39Q.220S
  From late October in 2006, Hinode solar optical telescope (SOT) has
  started to produce series of 0.2-0.3 arcsec visible-light images,
  revealing dynamical behaviors of solar magnetic fields on the
  solar surface. Simultaneously, Hinode X-ray telescope (XRT) has been
  providing 1 arcsec resolution X-ray images of the solar corona, giving
  the location of heating and dynamics occuring in the corona. Precise
  image co-alignment of SOT data on XRT data with sub-arcsec accuracy is
  required to provide new information regarding connecting the corona to
  the photosphere. This presentation will give an introduction of Hinode
  between-telescopes' image co-alignment to SPD participants. For active
  region observations with sunspots, sunspots can be used as fiducial to
  co-align the data from the two telescopes each other. Satellite jitter
  in order of 1 arcsec or less is included in the series of XRT data,
  whereas image stabilization system (correlation tracker) removes the
  satellite jitter from the series of SOT images. Telescope pointings show
  orbital variation in order of a few arcsec, which can be well predicted
  from Hinode orbit information. Modeling co-alignment is under study
  and it is the only precise method for quiet Sun and limb observations.

Title: Magnetic Flux Emergence In Granular Convection: Radiative
    MHD Simulations And Hinode SOT Observations
Authors: Cheung, Mark; Schüssler, M.; Moreno-Insertis, F.; Tarbell,
   T.; SOT Team
Bibcode: 2007AAS...210.9425C
Altcode: 2007BAAS...39..221C
  We model the emergence of buoyant magnetic flux from the convection
  zone into the photosphere by means of 3D radiative MHD simulations
  using the MURaM code. In a series of simulations, we study how
  an initially buoyant magnetic flux tube rises in the presence of
  granular convection. The simulations take into account the effects of
  radiative energy exchange, ionization effects in the equation of state
  and compressibility. An emphasis of this talk is the comparison of
  observational diagnostics from the simulations with recent observations
  from Hinode SOT.

Title: Hinode/SOT Observations Of Apparent "Thermal Plume" Motions
    In A Solar Prominence
Authors: Berger, Thomas; Tarbell, T.; Slater, G.; Tsuneta, S.;
   Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.; Shimizu, T.; Kubo, M.;
   Nagata, S.
Bibcode: 2007AAS...210.9433B
Altcode: 2007BAAS...39..222B
  We present 396.8 nm Ca II H-line observations of a large
  hedgerow, or "sheet", prominence seen on the solar western limb
  on 30-November-2006. The 16 second cadence observations show dark
  channels rising vertically at speeds of approximately 10 km/sec to
  heights of about 15 Mm above the limb. Many of the motions end in
  vortical overturning near the top of the sheet . Bright downflows of
  similar speed are also seen within the sheet, often in association
  with a dark channel that has risen to the top of the sheet. The dark
  channels are suggestive of hot material rising in thermal plumes
  within the prominence sheet. Similarly, the bright material motions
  appear to be density enhanced regions of turbulent downflow. Current
  models of sheet prominences do not include the observed dynamics. In
  these models, the prominence plasma is in a low-beta state and is
  constrained to move only along magnetic field lines. However the
  motions observed here are extremely complex, implying either that the
  magnetic field lines are undergoing turbulent motion, thus tangling
  and reconnecting constantly, or that the plasma is not constrained
  by the field and is in a high-beta convective state. We measure the
  motion of several representative "plumes" and downflows, estimate the
  density and temperature of the prominence plasma, and suggest several
  avenues for further investigation. <P />This work was supported by
  NASA under the Hinode/SOT contract NNM07AA01C.

Title: High Resolution Observation of Spicules in Ca II H with
    Hinode/SOT
Authors: Suematsu, Yoshinori; Katsukawa, Y.; Ichimoto, K.; Tsuneta, S.;
   Okamoto, T.; Nagata, S.; Shimizu, T.; Tarbell, T.; Shine, R.; Title, A.
Bibcode: 2007AAS...210.9411S
Altcode: 2007BAAS...39..219S
  High cadence observation with a Ca II H broadband filtergraph
  (passband of 0.25 nm) of the Solar Optical Telescope (SOT) aboard
  HINODE has revealed dynamical nature of solar limb spicules. Thanks to a
  diffraction-limited and low-scattered light property of the instrument,
  we can track the detailed evolution of individual spicules for the first
  time with a spatial resolution of 0.2 arcsec. The spicules in Ca II
  H are typically several arcsec tall and have multi-thread structure;
  each threads are a few tenth of arcsec wide. It should be stressed
  that most spicules do not show a simple up-and-down motion along a
  rigid path line. They start with bright structure emanating from Ca II
  H bright region, get widen and diffused with time and ascent, showing
  expansion with lateral or even helical motion in tall events. Small and
  short lived spicules tend to fade out after ascent. We will present
  new findings of spicule dynamics in different magnetic environments
  and discuss about long standing controversy of its motion and evolution.

Title: Hinode/SOT Observation of Fine Structure of the Evershed Flow
Authors: Ichimoto, Kiyoshi; Suematsu, Y.; Tsuneta, S.; Katsukawa, Y.;
   Shimojo, M.; Kubo, M.; Shimizu, T.; Shine, R.; Tarbell, T.; Title,
   A.; Lites, B.; Elmore, D.; Yokoyama, T.; Nagaka, S.
Bibcode: 2007AAS...210.9408I
Altcode: 2007BAAS...39..218I
  Small scale structure of the Evershed effect was studied using the
  Spectropolarimeter (SP) and Broadband Filter Imager (BFI) of SOT aboard
  Hinode. SP maps and high cadence continuum images of BFI coverting
  entire sunspots are used to investigate the spatial distribution of
  the flow field, brightness and magnetic fields. It is revealed that the
  Evershed flow starts at the front edge of inwardly migrating penumbral
  grains with an upward velocity component and turns to nearly holizontal
  flow preferentially in dark lanes (or dark core of filaments) of the
  penumbra. Our results are in general agreement with the well known
  uncombed penumbral concept in which the Evershed flow takes place
  in nearly holizontal field channels. We discovered a number of tiny
  elongated regions in deep photosphere in which there is an obvious
  upward motion of 1-1.5km/s distributing over the penumbra. <P />They
  could be identified as the 'foot points' of the individual Evershed
  flow channels. Cross-correlation among the flow speed, intensity,
  magnetic field strength and inclination, and distribution of string
  down flows in and around the penumbra will also be discussed.

Title: Observational Evidence For The Ubiquity Of Strong Alfven
    Waves In The Magnetized Chromosphere
Authors: De Pontieu, Bart; McIntosh, S. W.; Carlsson, M.; Hansteen,
   V. H.; Schrijver, C. J.; Tarbell, T. D.; Title, A.; SOT Team
Bibcode: 2007AAS...210.9415D
Altcode: 2007BAAS...39R.219D
  Hinode/SOT Ca II broadband observations show that Alfven waves with
  significant amplitudes of order 10-20 km/s and periods of 150-300 s are
  extremely ubiquitous in the magnetized middle to upper chromosphere. Our
  observations focus on spicules at the limb, and straw-like features
  associated with network and plage on the disk. We find that the
  weak straw-like features and most spicules all undergo significant
  transverse motions that are driven by Alfven waves. These waves are
  seen to propagate both up- and downward, and may carry an energy flux
  that is significant compared to both the local, coronal and solar wind
  energy balance. We will provide estimates of the energy flux carried
  by these waves, and will compare our observations with Alfven waves
  that are observed in 3D numerical simulations that include advanced
  radiative transfer treatment for the chromosphere. <P />This work was
  supported by NASA contract NNM07AA01C.

Title: A Tale of Two Spicules
Authors: McIntosh, Scott W.; De Pontieu, B.; Carlsson, M.; Hansteen,
   V. H.; Schrijver, C. J.; Tarbell, T. D.; Title, A. M.; SOT Team
Bibcode: 2007AAS...210.9414M
Altcode: 2007BAAS...39..219M
  Hinode/SOT Ca II broadband images and movies show that there are
  several different types of spicules at the limb. These different
  types are distinguished by dynamics on different timescales. The
  first type involves up- and downward motion on timescales of 3-5
  minutes. The dynamics of these spicules are very similar to those of
  fibrils and mottles as observed on the disk. Recent work suggests that
  these are driven by slow-mode magnetoacoustic shocks that form when
  convective flows and global oscillations leak into the chromosphere
  along magnetic flux tubes. The second type is much more dynamic with
  typical lifetimes of 10-60 s. These spicules are characterized by
  sudden appearance and disappearance that may be indicative of rapid
  heating to TR temperatures. We will describe the properties of these
  spicules in various magnetic environments (coronal hole, quiet Sun,
  active region) and study the possible role of reconnection in driving
  the second type of spicules. In addition, we will perform detailed
  comparisons of these different types of jets with synthetic Ca images
  derived from advanced 3D numerical simulations that encompass the
  convection zone up through the corona.

Title: Magnetic Flux Emergence In The Quiet Sun Photosphere
Authors: Centeno, Rebecca; Lites, B.; Socas-Navarro, H.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Tsuneta, S.;
   Katsukawa, Y.; Suematsu, Y.; Kubo, M.; Shimizu, T.
Bibcode: 2007AAS...210.9406C
Altcode: 2007BAAS...39..218C
  We study the emergence of magnetic flux at very small spacial scales
  (less than 1 arcsec) in the quiet Sun internetwork. To this aim, several
  time series of spectropolarimetric maps were taken at disk center using
  the instrument SP/SOT on board Hinode. The LTE inversion of the full
  Stokes vector measured in the Fe I 6301 and 6302 lines will allow us
  to retrieve the magnetic flux and topology in the region of study. We
  find that the magnetic flux emerges typically within the granular
  structures. In many cases, the horizontal magnetic field appears
  prior to any significant amount of vertical field. As time goes on,
  the traces of the horizontal field dissapear while the the vertical
  dipoles drift -carried by the plasma motions- towards the surrounding
  intergranular lanes. Sometimes they stay trapped there for a while
  but they eventually either disappear by disgregation/cancelation
  or agregate to other magnetic field concentrations giving rise to
  larger flux elements. The time scale of these events is of the order
  of 10-20 minutes.

Title: Formation of Moving Magnetic Features and Penumbral Magnetic
    Fields
Authors: Kubo, Masahito; Ichimoto, K.; Shimizu, T.; Tsuneta, S.;
   Suematsu, Y.; Katsukawa, Y.; Nagata, S.; Lites, B. W.; Frank, Z.;
   Tarbell, T. D.; Shine, R. A.; Title, A. M.
Bibcode: 2007AAS...210.9410K
Altcode: 2007BAAS...39..218K
  We investigate the formation process of Moving Magnetic Features
  (MMFs) observed with Hinode/SOT. Moving magnetic features are small
  magnetic elements moving outward in the moat region surrounding
  mature sunspots. We derive vector magnetic fields of MMFs around
  simple sunspots near the disk center. Most of MMFs with polarity
  opposite to the sunspot have large redshift around the penumbral outer
  boundary. We find that some of them have Doppler velocities of about
  10 km/s and such large Doppler motion is observed only in the Stokes
  V profile. The Stokes Q and U profiles in the same pixel do not have
  any significant Doppler motions. Horizontal magnetic fields of the
  penumbra frequently extend to the moat region and the MMFs having
  horizontal fields with polarity same as the sunspot are formed. The
  MMFs with polarity opposite to the sunspot appear around the outer
  edge of the extending penumbral fields. We also find penumbral spines,
  which have more vertical magnetic fields than the surroundings, branch
  off at their outer edge and MMFs having relatively vertical fields
  with polarity same as the sunspot are detached from the outer edge
  of the branch. The branch of penumbral spine is formed when granular
  cells in the moat region go into the penumbra.

Title: Ubiquitous Horizontal Magnetic Fields in the Quiet Solar
    Photosphere as Revealed by HINODE Meaurements
Authors: Lites, Bruce W.; Socas Navarro, H.; Berger, T.; Frank,
   Z.; Shine, R.; Tarbell, T.; Title, A.; Ichimoto, K.; Katsukawa,
   Y.; Tsuneta, S.; Suematsu, Y.; Kubo, M.; Shimizu, T.; Nagata, S.;
   Hinode Team
Bibcode: 2007AAS...210.6303L
Altcode: 2007BAAS...39..171L
  Measurements with the HINODE Spectro-Polarimeter (SP) of the quiet
  Sun allow characterization of the weak, mixed-polarity magnetic
  flux at the highest angular resolution to date (0.3"), and with good
  polarimetric sensitivity(0.025% relative to the continuum). The image
  stabilization of the HINODE spacecraft allows long integrations with
  degradation of the image quality only by the evolution of the solar
  granulation. From the Stokes V profile measurements we find an average
  solar "Apparent Flux Density" of 14 Mx cm-2, with significant Stokes V
  signals at every position on the disk at all times. However, there are
  patches of meso-granular size (5-15") where the flux is very weak. At
  this high sensitivity, transverse fields produce measurable Stokes
  Q,U linear polarization signals over a majority of the area, with
  apparent transverse flux densities in the internetwork significantly
  larger than the corresponding longitudinal flux densities. When viewed
  at the center of the solar disk, the Stokes V signals (longitudinal
  fields) show a preference for occurrence in the intergranular lanes,
  and the Q,U signals occur preferably over the granule interiors,
  but neither association is exclusive. <P />Hinode is an international
  project supported by JAXA, NASA, PPARC and ESA. We are grateful to the
  Hinode team for all their efforts in the design, build and operation
  of the mission.

Title: The Solar Optical Telescope on Hinode: Performance and
    Capabilities
Authors: Tarbell, Theodore D.; Tsuneta, S.; SOT Team
Bibcode: 2007AAS...210.9401T
Altcode: 2007BAAS...39..217T
  The Hinode (Solar B) satellite includes the Solar Optical Telescope
  (SOT) with its 50 cm diameter Optical Telescope Assembly (OTA) and
  Focal Plane Package (FPP), for near UV and visible observations of
  the photosphere and chromosphere at very high (diffraction limited)
  angular resolution. The FPP has a Spectropolarimeter (SP) for precision
  measurements of photospheric vector magnetic fields over a 160 x
  320 arcsecond field of view; a Narrowband Filter Imager (NFI) with
  a tunable birefringent filter for magnetic, Doppler, and intensity
  maps over the same field of view; and a Broadband Filter Imager (BFI)
  for highest resolution images in six wavelengths (G band, Ca II H,
  continua, etc.) over two thirds of that field of view. A polarization
  modulator in the telescope allows measurement of Stokes parameters at
  all wavelengths in the SP and NFI. This poster gives examples of SOT
  observables from the performance verification and initial observing
  phases of the mission. The SP routinely collects Stokes profiles with
  spatial resolution 0.16 arc seconds (pixel) and rms noise less than
  0.001. Initially the NFI only made magnetograms in Fe I 6302.5 with
  rms noise less than 0.002; more recently it has begun to observe
  the other photospheric and chromospheric lines available. The BFI
  movies have unprecedented uniformity and stability for such high
  spatial resolution; cadence can be 4 seconds or less. All images are
  stabilized to 0.01 arc seconds by a tip tilt mirror and correlation
  tracker. The process for requesting Hinode observations is described,
  along with guidelines for SOT observing programs. Starting in May, 2007,
  the Hinode data policy becomes completely open, with all data available
  to the community immediately after receipt and reformatting at ISAS. <P
  />Hinode is an international cooperative mission between JAXA/ISAS of
  Japan, NASA of the United States, PPARC of the United Kingdom, and ESA.

Title: Can High Frequency Acoustic Waves Heat the Quiet Sun
    Chromosphere?
Authors: Carlsson, Mats P. O.; De Pontieu, B.; Tarbell, T.; Hansteen,
   V. H.; McIntosh, S.; SOT Team
Bibcode: 2007AAS...210.6306C
Altcode: 2007BAAS...39..172C
  We use Hinode/SOT Ca II, G-band and blue continuum broadband
  observations to study the presence and power of high frequency acoustic
  waves at high spatial resolution. Previous observations with TRACE,
  which were limited by the 1 arcsec resolution, and 1D numerical
  simulations (Fossum &amp; Carlsson, 2005) have been used to constrain
  the possible role of high frequency waves in the heating of the quiet
  Sun chromosphere. We will use the higher spatial resolution Hinode
  data and comparisons with both 1D and 3D numerical models to study
  the amount of high frequency power at smaller scales, and whether that
  power is sufficient to heat the quiet Sun chromosphere.

Title: First Results from the Solar Optical Telescope on Hinode
Authors: Title, Alan M.; Tarbell, T.; Tsuneta, S.; SOT Team
Bibcode: 2007AAS...210.6301T
Altcode: 2007BAAS...39..171T
  The Solar Optical Telescope (SOT) is a joint project of the National
  Observatory of Japan and the Lockheed Martin Solar and Astrophysical
  Laboratory. SOT consists of a 50 cm Gregorian telescope optimized to
  reduce instrumental polarization and the Focal Plane Package (FPP). FPP
  contains a version of the Advanced Stokes Polarimeters developed by
  the High Altitude Observatory, a broadband filter system, and a tunable
  birefringent filter. A correlation tracker in the FPP sends a control
  signal to an active mirror in the telescope. Both the telescope and the
  active mirror were developed by the National Astronomical Observatory
  of Japan. The correlation tracking system reduces image motion in the
  focal planes to +/- 0.02 arcseconds. The diffraction limited performance
  of the SOT coupled with large format CCD’s and high data rates have
  allowed the construction of high resolution line of sight and vector
  magnetograms and imaging of phenomena on solar surface and off the
  solar limb. This data are providing new insights into the processes
  of flux emergence and disappearance from the scale of granulation to
  active regions. High cadence observations of filaments, prominences,
  and spicules have revealed surprising evolutionary features that include
  alfven waves, current systems, and rapid reconnection. Movies of many
  of these phenomena will be shown.

Title: Attempt to detect Aflven waves with Solar Optical Telescope
    aboard Hinode
Authors: Tsuneta, Saku; Suematsu, Y.; Ichimoto, K.; Katsukawa, Y.;
   Shimizu, T.; Nagata, S.; Orozco Suárez, D.; Lites, B.; Shine, D.;
   Tarbell, T.; Title, A.
Bibcode: 2007AAS...210.9428T
Altcode: 2007BAAS...39..222T
  Flux tube on the sun may carry linear and torsional Alfven waves
  generated by photospheric motion. Photospheric motion of 2 km/s would
  provide magnetic fluctuation of 40G for 1KG tube and for the Alfven
  speed of 50km/s. This may be close to the detection limit of the Stokes
  Q and U signals for flux tubes located in the sun center. However,
  for flux tubes located near the limb, the fluctuation would be seen in
  the Stokes V signal, and can be detectable. <P />We also may be able
  to confirm the 90 degree phase shift between magnetic fluctuation and
  velocity fluctuation, which is easier to observe for flux tubes near
  the limb. Detection of waves would be important in terms of coronal
  heating and solar wind acceleration. An attempt to detect waves along
  flux tubes will be reported.

Title: Discovery Of Cool Cloud-like Structures In The Corona With
    Hinode Solar Optical Telescope
Authors: Okamoto, Takenori; Tsuneta, S.; Katsukawa, Y.; Ichimoto,
   K.; Suematsu, Y.; Shimizu, T.; Nagata, S.; Shibata, K.; Tarbell, T.;
   Shine, R.; Berger, T.; Lites, B.; Myers, D.
Bibcode: 2007AAS...210.9426O
Altcode: 2007BAAS...39..221O
  A solar observation satellite Hinode (Japanese for sun rise) was
  launched in September 2006.Hinode carried 3 advanced solar telescopes,
  visible light telescope, EUV imaging spectrometer, and X-ray telescope
  to simultaneously observe the photosphere, chromosphere, transition
  region, and corona. In the performance verification phase of the Hinode
  spacecraft with its telescopes, we observed an active region AR10921
  near the west limb of the solar disk on November 9 2006. At this point,
  we planned to observe spicules on the limb with a broadband filter
  dedicated to Ca II H line (3968A). Ca II-H emission line (3968A) comes
  from plasma with temperature of approx. 10(4) K, which is much lower
  than the coronal temperature of 10(6-7) K. In addition to spectacular
  spicules, we find a large cloud-like structure located 10,000-20,000
  km above the limb. The cloud has a very complex fine structure with
  dominant horizontal thread-like structure. Some features are moving
  horizontally and also have clear vertical oscillatory motions. The
  periods and amplitudes of these oscillations are 130-250 seconds and
  200-850 km, respectively. The vertical oscillatory motion sometimes
  has a coherence length as long as 16,000 km. We conclude that from
  various observational features this vertical oscillation is a signature
  of Alfven waves propagating along the horizontal magnetic fields. We
  will discuss their origin and implications.

Title: Discovery Of Small-scale Horizontal Magnetic Structures On
    The Solar Photosphere
Authors: Ishikawa, Ryohko; Tsuneta, S.; Suematsu, Y.; Ichimoto, K.;
   Katsukawa, Y.; Nagata, S.; Ishobe, H.; Tarbell, T.; Lites, B. W.;
   Title, A.
Bibcode: 2007AAS...210.9404I
Altcode: 2007BAAS...39..217I
  We discover two different types of episodes on the appearance
  of horizontal magnetic fields with Solar Optical Telescope aboard
  Hinode. <P />The first episode is an emergence of strong thin horizontal
  magnetic fields associated with separating vertical components on
  both ends. Its size is about two granules. We also detect strong area
  asymmetry of the environment Stokes Vprofile for the bout 8 minutes
  before the first emergence of the horizontal component. One of the
  footpoints has very strong downflows (several km/s), while the region
  with strong linear polarization signal has small blue shift, indicating
  an upward-moving horizontal flux. <P />The second episode appears to be
  more ubiquitous. Linear polarization signals appear inside granules (not
  in inter-granules). Their size is smaller than granules, and lifetime
  is longer than several minutes. We will summarize the nature of the
  two types of the horizontal magnetic fluxes, and discuss their origin.

Title: Hinode/SOT Observations of Sunspot Penumbral Dynamics and
    Evolution
Authors: Shine, Richard A.; Hagenaar, M.; Tarbell, T.; Title, A.;
   Lites, B.; Ichimoto, K.; Tsuneta, S.; Katsakawa, Y.; Suematsu, Y.;
   Nagata, S.; Kubo, M.; Shimizu, T.
Bibcode: 2007AAS...210.9407S
Altcode: 2007BAAS...39..218S
  The Solar Optical Telescope (SOT) on the Hinode satellite (launched
  October 2006) has obtained long and nearly continuous time series of
  several large sunspots including those in NOAA AR's 10923, 10925,
  and 10930. Here we use high resolution movies taken primarily with
  the broad band Ca II (396.8nm) and G band (430.5nm) channels and
  magnetograms taken with the 630.2nm narrow band channel to study
  the details and short term evolution of penumbral fine structures
  as well as the long term evolution of the sunspots. We compute flow
  maps and use space/time slices to track motions of Evershed clouds,
  penumbral grains, and visualize oscillations. The data contain examples
  of penumbral formation and disintegration including "orphan" penumbra
  (i.e., penumbra without an obvious umbra). There is also an interesting
  instance of "colliding" penumbra in AR 10930 as two sunspots of opposite
  polarity converged. The zone of apparent shear was associated with
  several flares. <P />This work was supported by NASA contract NNM07AA01C

Title: Magnetic Landscape Of Solar Polar Region With Solar Optical
    Telescope Aboard Hinode
Authors: Tsuneta, Saku; Suematsu, Y.; Ichimoto, K.; Shimizu, T.;
   Katsukawa, Y.; Nagata, S.; Orozco Suárez, D.; Lites, B.; Shine, D.;
   Tarbell, T.; Title, A.
Bibcode: 2007AAS...210.9405T
Altcode: 2007BAAS...39..218T
  Solar polar region is the final destination for remnant magnetic
  fields due to meridional flow and granular diffusion, and is very
  important for the global solar dynamo. Hinode satellite carried out
  high-resolution spectro-polarimetric observations for the Northern
  pole on 2006 November 22 as a part of its performance verification
  program. We find ubiquitous isolated (positive and negative) patches
  in the Stokes V map (i.e. fields horizontal to local surface) all over
  the Arctic circle. The Q (vertical to local surface) map indicates
  scattered vertical flux tubes, which have bipolar feature in the U and
  V maps. This suggests canopy-like structure of the strong isolated flux
  tubes. This will be compared with equatorial landscape with similar
  distance from the sun center. Strong flux tube and weaker ubiquitous
  horizontal fields as represented by Stokes V would have implication
  to the current understanding of the global and local dynamo.

Title: First Results From The Solar-B Mission, Part II
Authors: Tarbell, T.; Team, S. I.
Bibcode: 2006AGUFMSH23A0338T
Altcode:
  This poster continues showing first results from the instruments on
  Solar-B. The Solar-B Observatory is a highly capable satellite equipped
  with three advanced solar telescopes. Its Solar Optical Telescope (SOT)
  has an unprecedented 0.2 arcsec resolution for observation of the solar
  atmosphere from space in multiple optical passbands. It will also,
  for the first time, measure the vector magnetic fields from space. The
  X-Ray Telescope (XRT) has broad temperature coverage and a spatial
  a resolution three times as high as Yohkoh. The image cadence will
  be significantly higher than Yohkoh's and a flare buffer will provide
  exceptional capability for observing rapid changes at flare onset. The
  EUV Imaging Spectrometer (EIS) has sensitivity ten times as high as the
  SOHO CDS instrument and covers a broad range of transition region and
  coronal temperatures. Flexible operating modes permit slit, slot and
  raster options in a selectable number of spectral lines. Both XRT and
  EIS have 2 arcsec spatial resolution (1 arcsec pixels). Solar-B is the
  follow-up mission to the very successful Japan/UK/US Yohkoh mission. We
  present a status report from the initial operation of the observatory,
  showing some of the first observations obtained. Following a short
  commissioning phase, science planning and regular operations are due
  to begin January 2007. Starting six months after launch, all mission
  data will be open and freely available to researchers shortly after
  receipt at the DARTS data archive hosted in Japan.

Title: Magnetic Field Diagnostic Capability of Solar-B/SOT:
    Filtergraph Instrument
Authors: Ichimoto, K.; Suematsu, Y.; Shimizu, T.; Katsukawa, Y.;
   Tsuneta, S.; Tarbell, T. D.; Shine, R. A.; Hoffmann, C. M.; Title,
   A. M.; Lites, B. W.; Elmore, D. F.; Streander, K. V.
Bibcode: 2006ASPC..358..189I
Altcode:
  The Narrowband Filter Instrument (NFI) of the Solar Optical Telescope
  onboard Solar-B provides 2D magnetograms/Dopplergrams with a tunable
  Lyot filter (width ∼ 0.1 Å) in 6 selected wavelength bands, and
  spatial sampling of 0.08 arcsec/px. The Zeeman-effect sensitivity of
  NFI and the detection limits of weak magnetic fields are evaluated for
  2 photospheric and 3 chromospheric lines. Magnetic-field retrievability
  from the NFI observables is studied using synthetic Stokes profiles
  of Fe I 5250 Å. We find that, with optimized wavelength sampling at 4
  positions, the inferred magnetic field is sufficiently accurate under
  the hypothesis of constant magnetic field and velocity along the LOS.

Title: Gamma Rays and the Evolving, Compact Structures of the 2003
    October 28 X17 Flare
Authors: Schrijver, C. J.; Hudson, H. S.; Murphy, R. J.; Share, G. H.;
   Tarbell, T. D.
Bibcode: 2006ApJ...650.1184S
Altcode:
  The X17 flare on 2003 October 28 was observed by high-resolution
  imaging or spectroscopic instruments on CORONAS, GOES, INTEGRAL,
  RHESSI, SOHO, and TRACE. These spacecraft observed the temporal
  evolution of the γ-ray positron-annihilation and nuclear de-excitation
  line spectra, imaged the hard X-ray bremsstrahlung and EUV and UV
  emission, and measured the surface magnetic field and subphotospheric
  pressure perturbations. In the usual pattern, the onset of the flare
  is dominated by particle acceleration and interaction, and by the
  filling of coronal magnetic structures with hot plasma. The associated
  positron-annihilation signatures early in the impulsive phase from
  11:06 to 11:16 UT have a line-broadening temperature characteristic of
  a few hundred thousand kelvins. The most intense precipitation sites
  within the extended flare ribbons are very compact, with diameters
  of less than 1400 km, and a 195 Å TRACE intensity that can exceed
  7500 times the quiescent active-region value. These regions appear to
  move at speeds of up to 60 km s<SUP>-1</SUP>. The associated rapidly
  evolving, compact perturbations of the photosphere below these sites
  excite acoustic pulses that propagate into the solar interior. Less
  intense precipitation sites typically persist for several minutes
  behind the advancing flare ribbons. After ~1 ks, the flare enters
  a second phase, dominated by coronal plasma cooling and downflows
  and by annihilation-line radiation characteristic of a photospheric
  environment. We point out (1) that these detailed observations
  underscore that flare models need to explicitly incorporate the
  multitude of successively excited environments whose evolving signals
  differ at least in their temporal offsets and energy budgets, if not
  also in the exciting particle populations and penetration depths, and
  (2) that the spectral signatures of the positron annihilation do not
  fit conventional model assumptions.

Title: The Focal Plane Package of the Solar Optical telescope on
    Solar B
Authors: Tarbell, Theodore D.
Bibcode: 2006SPD....37.3602T
Altcode: 2006BAAS...38..260T
  The Solar-B satellite will be launched into a full-sun low-earth
  orbit in the fall of 2006 from Japan's Uchinoura Space center. It
  includes the 50-cm diameter Solar Optical Telescope with its Focal
  Plane Package (FPP), for near-UV and visible observations of the
  photosphere and chromosphere at very high (diffraction limited)
  angular resolution. The FPP has a Spectro-Polarimeter (SP) for
  precision measurements of photospheric vector magnetic fields over
  a 160 x 320 arcsecond field of view; a Narrowband Filter Imager
  (NFI) with a tunable birefringent filter for magnetic, Doppler, and
  intensity maps over the same field of view; and a Broadband Filter
  Imager (BFI) for highest resolution images in six wavelengths (G band,
  Ca II H, continua, etc.) over two-thirds of that field of view. A
  polarization modulator in the telescope allows measurement of Stokes
  parameters at all wavelengths in the SP and NFI. The NFI wavelengths
  include both photospheric and chromospheric lines (Fe I, Mg b, Na D,
  H-alpha). All images are stabilized by a tip-tilt mirror and correlation
  tracker. This presentation will include pictures and description of
  the instrument, results from calibration and sun testing, portions
  of the draft science plan, and some preliminary JOP's. Solar-B is an
  international cooperative mission between JAXA/ISAS of Japan, NASA of
  the United States, and PPARC of the United Kingdom. The Solar Optical
  Telescope has been developed by the National Astronomical Observatory
  of Japan, Mitsubishi Electric Company, and JAXA/ISAS. The FPP has
  been developed by the Lockheed Martin Advanced Technology Center,
  High Altitude Observatory, and NASA.

Title: Analysis of Solar Flare Ribbon Evolution: A Semiautomated
    Approach
Authors: Saba, J. L. R.; Gaeng, T.; Tarbell, T. D.
Bibcode: 2006ApJ...641.1197S
Altcode:
  We exploit a rare joint set of high-resolution, very high cadence
  TRACE UV images and high-resolution magnetograms from SOHO MDI to
  investigate the dynamical properties of flare ribbons in a GOES M1
  class flare from NOAA active region 9236 on 2000 November 23 at 23:28
  UT. Assuming that flare ribbons locate the chromospheric footpoints of
  magnetic field lines reconnecting in the corona and that magnetic flux
  is conserved, we measure the magnetic reconnection rate (in maxwells
  per second) by overlaying the ribbons on co-registered magnetograms
  and using intensity-based binary masks to track the magnetic flux
  swept over by the evolving ribbons, and by assumption swept up in
  the reconnection. In the event observed, the ribbons did not separate
  with time but remained stationary while they brightened, lengthened,
  and faded in place. Thus, the ribbons may be akin to hard X-ray flare
  kernels moving antiparallel to each other, which others interpret as
  caused by strong photospheric shear. The derived reconnection rate is
  noisy, with little correlation between adjacent 1.4 s samples; the
  peak rate for pixels summed over the ribbon is ~5×10<SUP>18</SUP>
  Mx s<SUP>-1</SUP> the average rise-phase rate is 10 times lower. The
  ``local'' rates for adjacent pixels added to the ribbon at adjacent
  times show correlations with 1600 Å band intensities, supporting the
  reconnection interpretation. For simple assumptions about geometry, the
  reconnection appears fast (V<SUB>in</SUB>&gt;=0.01V<SUB>A</SUB>). The
  peak reconnection rates, along with estimates of the current-sheet
  length scale suggested by measured quantities, imply peak electric
  fields of order 40 V cm<SUP>-1</SUP>. We discuss caveats to these
  results.

Title: Self-focusing of Shocks and Hydrodynamic Cumulation in the
    Solar Atmosphere
Authors: Tarbell, T.; Ryutova, M.
Bibcode: 2005AGUFMSH53A1251T
Altcode:
  Network magnetic field in the solar atmosphere is concentrated
  in isolated non-collinear thin flux tubes embedded in almost
  non-magnetic environment with plasma beta β=8π pext/Bext2&gt;&gt;
  1. Brought together by convective motions flux tubes collide and
  reconnect. Post-reconnection dynamics of the photospheric magnetic flux
  tubes is radically different from a low beta coronal plasma. Here
  the reconnection does not give in situ heating, but it sets the
  system in a highly unsteady state. After reconnection, the strongly
  curved flux tubes behave as elastic bands: straightening they create
  a sling-shot effect which generates complex 3D shock waves with the
  curved surface. Self-focusing of these shocks occurs as they propagate
  upward in the stratified atmosphere, producing a strong cumulative
  effects. Depending on the geometry of the shock conversion, highly
  concentrated energy may be either converted entirely into heat or into
  strong jets, or be distributed between the two. These processes have
  been observed in simultaneous observations of the solar atmosphere
  from its surface to the corona obtained with the Solar and Heliospheric
  Observatory (SOHO) and Transition Region and Coronal Explorer (TRACE)
  showing a ubiquitous sequence of events that start from cancellation of
  photospheric magnetic fields, pass through shock formation and result in
  the transition region supersonic jets and microflares (Ryutova &amp;
  Tarbell, 2003, Physical Review Letters, 90, 191101). We also find
  that lateral shocks produced by the reconnection of the same polarity
  non-collinear magnetic flux tubes may cause the ubiquitous bright points
  observed in sunspots and their environment. The mechanisms of energy
  flow and release in the solar atmosphere involve fundamental physical
  processes that are commonplace throughout astrophysics and laboratory
  plasma physics. The advances in the coordinated observations with SOHO
  and TRACE provide a unique opportunity to check the theoretical models,
  and shed light on the general mechanisms of energy production, transfer
  and release in stellar atmospheres and other astrophysical objects.

Title: The TRACE Inter-Network Oscillations (INO) Program II:
    Observations of Limb and Coronal Hole Regions
Authors: McIntosh, S. W.; Crotser, D.; Leamon, R. J.; Fleck, B.;
   Tarbell, T. D.
Bibcode: 2005AGUSMSH13C..06M
Altcode:
  We will present results of the TRACE Inter-Network Oscillations (INO)
  observing program from 2003 to the present. The INO program uses
  near-simultaneous observations in the 1600Å and 1700Å UV continuum
  pass bands as an acoustic probe of chromospheric structure. In
  this poster we will discuss the INO observations of limb, polar and
  coronal hole regions and show the key results found, thus far. These
  observations offer us a remote means to study the structure and behavior
  of the chromopsheric plasma topography at a potential driving base
  for the heliospheric plasma system.

Title: The Focal Plane Package for the Solar Optical Telescope
    on Solar-B
Authors: Tarbell, T. D.
Bibcode: 2005AGUSMSP43A..03T
Altcode:
  Solar-B is a space science mission of the Japanese Aerospace Exploration
  Agency (JAXA) and a NASA Solar Terrestrial Probes mission. It
  includes the 50-cm aperture Solar Optical Telescope (SOT), with its
  Focal Plane Package (FPP) designed for high resolution photospheric
  and chromospheric imaging and spectro-polarimetry. There are also
  two coronal instruments, the X-Ray Telescope and Extreme-ultraviolet
  Imaging Spectrometer. Solar-B will be launched into a Sun-synchronous
  polar orbit in August, 2006. The SOT is provided by JAXA and is
  being built by the National Astronomical Observatory of Japan (NAOJ)
  and Mitsubishi Electric Co. A team of Lockheed Martin, High Altitude
  Observatory (HAO), and NAOJ scientists and engineers have built the
  FPP instrument. This paper gives an overview of the science goals of
  the FPP as well as the instrument performance characteristics. The
  primary goal is to understand the coupling between the fine magnetic
  structures in the photosphere and dynamic processes and heating
  in the chromosphere and corona. The FPP consists of a narrow-band
  tunable birefringent filter imager, broad-band interference filter
  imager, and spectro-polarimeter (SP), essentially a space version
  of the HAO Advanced Stokes Polarimeter. The image is stabilized by a
  correlation tracker and active tilt mirror. The SP makes vector magnetic
  measurements from Stokes spectra of the Fe I lines 630.1 and 630.2 nm,
  with 0.16 arcsec pixels and field of view up to 164 x 328 arcsec. The
  broad-band system takes diffraction-limited images (0.05 arcsec pixels)
  in the Ca II H line, CN and G bandheads, and continuum bands. The
  narrow-band system makes filtergrams, magnetograms, Dopplergrams, and
  Stokes images in several photospheric lines, Mg b, Na D, and H-alpha,
  similar to the SOUP filter at La Palma. It has 0.08 arcsec pixels and
  field-of-view same as that of the SP. SOT and FPP have been calibrated
  in great detail and have observed the sun in two end-to-end tests at
  NAOJ. Sample results of these observations will be shown. Observing
  programs and coordination with the other instruments and observatories
  during the mission will be managed by SOT/FPP science planners, similar
  to those of SOHO and TRACE. The FPP project is supported by NASA
  (NAS8-01002).

Title: Calibration and Tesing of the Tunable Filter on Solar B
Authors: Shine, R. A.; Title, A. M.; Tarbell, T. D.; Mitchell, K.;
   Tavarez, L.; Rosenberg, W.
Bibcode: 2005AGUSMSP43A..04S
Altcode:
  The tunable filter in the Focal Plane Package (FPP) on the Japanese
  Solar B satellite, scheduled for launch in August 2006, was designed,
  built, and tested at the Lockheed Martin Advanced Technology Center
  (LMATC). It is an eight element wide field calcite filter (an improved
  Lyot type) with a spectral resolution of about 100mÅ and a tuning range
  of 11.87Å at 6302Å. Using 6 prefilters, it operates in bands covering
  the 5172Å Fe I, 5250Å Fe I, 5576Å Fe I, 5896Å Na I, 6302Å Fe I,
  and 6563Å H I lines. Here we describe the testing and calibrations
  used to determine the tuning parameters as functions of temperature
  and wavelength for the six bands. We also measure performance using
  sunlight and laser sources in a standalone mode and integrated into
  the FPP package. Images and derived magnetograms and Dopplergrams
  using a low resolution solar image have also been obtained while
  attached to the Solar B telescope and using a heliostat at the LMATC
  in Palo Alto. In the course of this work we have also refined the
  mathematical description for these types of filters, especially the
  error terms that arise from residual misalignments. In particular,
  we now believe we understand the intensity oscillations seen in this
  and earlier Lyot tunable filters.

Title: Travel Time and Phase Analysis of Waves in the Lower Solar
    Chromosphere
Authors: Fleck, B.; Armstrong, J.; Cacciani, A.; de Pontieu, B.;
   Finsterle, W.; Jefferies, S. M.; McIntosh, S. W.; Tarbell, T. D.
Bibcode: 2005AGUSMSH13C..04F
Altcode:
  In an effort to better understand how the chromospheric plasma and
  magnetic fields are guiding, converting and dissipating acoustic waves,
  we analyze high-cadence time series taken in Na I D2 589.0 nm and K I
  769.9 nm that were obtained with the Magneto Optical Filters at Two
  Heights (MOTH) experiment at the South Pole in January 2003. These
  data are complemented by a very high spatial resolution time series
  taken in Na D with the Swedish Vacuum Solar Telescope in June 1992. The
  travel time maps, power maps, and phase diagrams show some unexpected
  behaviour, in particular in and around active regions.

Title: The TRACE Inter-Network Oscillations (INO) Program I: Probing
    Chromospheric Topography
Authors: McIntosh, S. W.; Bernhard, F.; Tarbell, T. D.
Bibcode: 2005AGUSMSH13C..05M
Altcode:
  We will present results of the TRACE Inter-Network Oscillations (INO)
  observing program from 2003 to the present. The INO program uses
  near-simultaneous observations in the 1600Å and 1700Å UV continuum
  pass bands as an acoustic probe of chromospheric structure. In the
  two years of INO observations we have studied a large number of quiet
  chromosphere and active regions as well as regions of the chromosphere
  under coronal holes. In this poster we will discuss the diagnostic
  methods applied to analyze the INO observations and the key results
  found, thus far. These diagnostic methods offer us a remote means to
  study the complex plasma topography of the solar chromosphere.

Title: The Next Generation of Chromospheric Measurements
Authors: Tarbell, T. D.
Bibcode: 2005AGUSMSH12A..06T
Altcode:
  I discuss the new measurements which we know will happen, from
  missions or observatories which are being developed now, as well as
  the measurements which should happen for further progress. The future
  is promising, with new missions such as Solar-B, SDO, and SunRise,
  and new or upgraded observatories, such as SVST, DOT, GREGOR, ATST,
  and FASR. I also point out significant needs for the future, such as
  detailed chromospheric spectroscopy of the type which would have been
  provided by NEXUS or similar instruments.

Title: Dynamics of the solar chromosphere. V. High-frequency
    modulation in ultraviolet image sequences from TRACE
Authors: de Wijn, A. G.; Rutten, R. J.; Tarbell, T. D.
Bibcode: 2005A&A...430.1119D
Altcode: 2007arXiv0706.1987D
  We search for signatures of high-frequency oscillations in the upper
  solar photosphere and low chromosphere in the context of acoustic
  heating of outer stellar atmospheres. We use ultraviolet image
  sequences of a quiet center-disk area from the Transition Region
  and Coronal Explorer (TRACE) mission which were taken with strict
  cadence regularity. The latter permits more reliable high-frequency
  diagnosis than in earlier work. Spatial Fourier power maps, spatially
  averaged coherence and phase-difference spectra, and spatio-temporal
  (k<SUB>h</SUB>,f) decompositions all contain high-frequency features
  that at first sight seem of considerable intrinsic interest but actually
  are more likely to represent artifacts of different nature. Spatially
  averaged phase difference measurement provides the most sensitive
  diagnostic and indicates the presence of acoustic modulation up to
  f≈20 mHz (periods down to 50 s) in internetwork areas.

Title: Image stabilization system on SOLAR-B Solar Optical Telescope
Authors: Shimizu, Toshifumi; Nagata, Shin'ichi; Edwards, Chris;
   Tarbell, Theodore; Kashiwagi, Yasuhiro; Kodeki, Kazuhide; Ito,
   Osamu; Miyagawa, Hiroyuki; Nagase, Masayuki; Inoue, Syunsaku; Kaneko,
   Kazumasa; Sakamoto, Yasushi; Ichimoto, Kiyoshi; Tsuneta, Saku; Miki,
   Shiro; Endo, Makoto; Tabata, Masaki; Nakaoji, Toshitaka; Matsuzaki,
   Keiichi; Kobayashi, Ken; Otsubo, Masashi; Suematsu, Yoshinori; Kumagai,
   Kazuyoshi; Noguchi, Motokazu; Tamura, Tomonori; Nakagiri, Masao
Bibcode: 2004SPIE.5487.1199S
Altcode:
  Extremely stable pointing of the telescope is required for images on the
  CCD cameras to accurately measure the nature of magnetic field on the
  sun. An image stabilization system is installed to the Solar Optical
  Telescope onboard SOLAR-B, which stabilizes images on the focal plane
  CCD detectors in the frequency range lower than about 20Hz. The system
  consists of a correlation tracker and a piezo-based tip-tilt mirror with
  servo control electronics. The correlation tracker is a high speed CCD
  camera with a correlation algorithm on the flight computer, producing
  a pointing error from series of solar granule images. Servo control
  electronics drives three piezo actuators in the tip-tilt mirror. A
  unique function in the servo control electronics can put sine wave
  form signals in the servo loop, allowing us to diagnose the transfer
  function of the servo loop even on orbit. The image stabilization
  system has been jointly developed by collaboration of National
  Astronomical Observatory of Japan/Mitsubishi Electronic Corp. and
  Lockheed Martin Advanced Technology Center Solar and Astrophysics
  Laboratory. Flight model was fabricated in summer 2003, and we measured
  the system performance of the flight model on a laboratory environment
  in September 2003, confirming that the servo stability within 0-20 Hz
  bandwidth is 0.001-0.002 arcsec rms level on the sun.

Title: Chromospheric Oscillations in an Equatorial Coronal Hole
Authors: McIntosh, Scott W.; Fleck, Bernhard; Tarbell, Theodore D.
Bibcode: 2004ApJ...609L..95M
Altcode:
  We report phase-difference and travel-time analyses of propagating
  chromospheric oscillations in and around an equatorial coronal hole
  as observed by TRACE. Our results suggest a significant change in
  atmospheric conditions at the base of the chromosphere inside the
  coronal hole relative to its boundary and quiet-Sun regions.

Title: EUVI: the STEREO-SECCHI extreme ultraviolet imager
Authors: Wuelser, Jean-Pierre; Lemen, James R.; Tarbell, Theodore
   D.; Wolfson, C. J.; Cannon, Joseph C.; Carpenter, Brock A.; Duncan,
   Dexter W.; Gradwohl, Glenn S.; Meyer, Syndie B.; Moore, Augustus S.;
   Navarro, Rosemarie L.; Pearson, J. D.; Rossi, George R.; Springer,
   Larry A.; Howard, Russell A.; Moses, John D.; Newmark, Jeffrey S.;
   Delaboudiniere, Jean-Pierre; Artzner, Guy E.; Auchere, Frederic;
   Bougnet, Marie; Bouyries, Philippe; Bridou, Francoise; Clotaire,
   Jean-Yves; Colas, Gerard; Delmotte, Franck; Jerome, Arnaud; Lamare,
   Michel; Mercier, Raymond; Mullot, Michel; Ravet, Marie-Francoise;
   Song, Xueyan; Bothmer, Volker; Deutsch, Werner
Bibcode: 2004SPIE.5171..111W
Altcode:
  The Extreme Ultraviolet Imager (EUVI) is part of the SECCHI instrument
  suite currently being developed for the NASA STEREO mission. Identical
  EUVI telescopes on the two STEREO spacecraft will study the structure
  and evolution of the solar corona in three dimensions, and specifically
  focus on the initiation and early evolution of coronal mass ejections
  (CMEs). The EUVI telescope is being developed at the Lockheed Martin
  Solar and Astrophysics Lab. The SECCHI investigation is led by the
  Naval Research Lab. The EUVI"s 2048 x 2048 pixel detectors have a
  field of view out to 1.7 solar radii, and observe in four spectral
  channels that span the 0.1 to 20 MK temperature range. In addition to
  its view from two vantage points, the EUVI will provide a substantial
  improvement in image resolution and image cadence over its predecessor
  SOHO-EIT, while complying with the more restricted mass, power, and
  volume allocations on the STEREO mission.

Title: MHD Shocks: The Origin of the Solar Transition Region and
    Coronal Sporadic Events
Authors: Ryutova, M. P.; Tarbell, T. D.
Bibcode: 2004ESASP.547..239R
Altcode: 2004soho...13..239R
  No abstract at ADS

Title: Correlations on Arcsecond Scales between Chromospheric and
    Transition Region Emission in Active Regions
Authors: De Pontieu, B.; Tarbell, T.; Erdélyi, R.
Bibcode: 2003ApJ...590..502D
Altcode:
  The discovery of active region moss, i.e., dynamic and bright upper
  transition region (TR) emission at chromospheric heights above active
  region plage, provides a powerful diagnostic to probe the structure,
  dynamics, energetics, and coupling of the magnetized solar chromosphere
  and TR. Here we present an observational study of the interaction
  of the chromosphere with the upper TR, by studying correlations (or
  lack thereof) between emission at varying temperatures: from the low
  chromosphere (Ca II K line), to the middle and upper chromosphere (Hα),
  to the low TR (C IV λ1550 at 0.1 MK) and the upper TR (Fe IX/X λ171
  at 1 MK and Fe XII λ195 at 1.5 MK). We use several data sets at high
  cadence (24-42 s) obtained with the Swedish Vacuum Solar Telescope
  (SVST, La Palma) and the Transition Region and Coronal Explorer
  (TRACE). This correlation analysis from low chromosphere to upper
  TR in active region plage quantifies and considerably expands on
  previous studies. Our results elucidate various issues, such as (1)
  how the heating mechanisms of the chromosphere and lower and upper TR
  are related (if at all), (2) how important heating of spicular jets is
  for the energy balance of the lower TR, (3) which timescales dominate
  the dynamic behavior of the active region TR, and (4) whether the
  spatial and temporal variability of moss can be used as a diagnostic
  for coronal heating.

Title: TRACE Image Flat Field and Sensitivity Corrections
Authors: Nightingale, R. W.; Tarbell, T. D.; Wolfson, C. J.
Bibcode: 2003SPD....34.1710N
Altcode: 2003BAAS...35..839N
  As of April 1, 2003, the TRACE instrument has been in orbit for 5
  years. During this time the lumogen phosphor coating on the CCD has
  degraded due to the flux of extreme ultraviolet (EUV) photons. We have
  utilized flat field images obtained for the UV 1700 Å and broad-band
  white light (WL) channels, together with the synoptic disk center,
  and low-resolution ``dosimeter'' image data from throughout the
  mission, to correct for the degradation at all of the TRACE UV and EUV
  wavelengths. A set of time dependent power and multiplier parameters
  have been determined from fitting these flat fields to the mission
  synoptic data for the various UV wavelengths. By comparing the relative
  EUV sensitivity at different positions on the detector throughout the
  mission using images of the same active region at different pointings,
  we have calibrated the sensitivity changes and flat fields at the
  EUV wavelengths, including 171 Å and 195 Å. The WL flat field
  images have not changed within +/-1.5 % over the mission to date. The
  WL flat fields are also used in the corrections for all images, to
  remove small artifacts intrinsic to the CCD and dust shadows common to
  certain channels. All these corrections have now been implemented as an
  update into the SolarSoft (SSW) routine TRACE_PREP.PRO, and normally
  are automatically applied to the images after the dark pedestal and
  current corrections. Plots of the time dependence of the sensitivity
  and examples of the flat field corrections, along with their use in
  TRACE_PREP.PRO, will be presented. This work was supported by the
  TRACE project at LMSAL (contract NAS5-38099).

Title: Time Profiles of Magnetic Reconnection Measured from Flare
    Ribbons
Authors: Tarbell, T.; Gaeng, T.; Saba, J.
Bibcode: 2003SPD....34.1614T
Altcode: 2003BAAS...35..835T
  We study flare ribbons using observations of very high temporal
  and spatial resolution to measure time profiles of magnetic
  reconnection. TRACE images in the 1600 band show flare ribbons in
  the low chromosphere, and we analyze M and X-class events with time
  resolution as high as a few seconds during the buildup, impulsive and
  decay phases. MDI high resolution magnetograms provide photospheric
  fields for estimation of reconnection rates in Mx/s. Another M-class
  event is studied with La Palma observations of very high spatial
  resolution but lower cadence; H-alpha images are used to locate the
  flare ribbons in this case. Both types of data show examples in weak
  plage or network where the flare ribbons do not overlie significant
  photospheric magnetic fields. We believe these ribbons are in the
  chromospheric magnetic canopy, where fields are nearly horizontal
  and flare heating can be widely separated from the photospheric
  footpoints. In regions of stronger fields, we argue that careful spatial
  coalignment of flare ribbons with photospheric fields can provide
  information about the time profile of reconnection in the corona. The
  reconnection rate is very noisy, with a correlation time of at most
  a few seconds. During the gradual buildup to one of the M flares,
  an exponential growth in reconnection rate by two orders of magnitude
  over 40 minutes before the impulsive phase is observed. Rates during the
  gradual decay of a long duration event are also measured. <P />This work
  was supported by NASA contracts NAG5-10483 (MDI) and NAS5-38099 (TRACE).

Title: MHD Shocks and the Origin of the Solar Transition Region
Authors: Ryutova, Margarita; Tarbell, Theodore
Bibcode: 2003PhRvL..90s1101R
Altcode:
  Simultaneous observations of the solar atmosphere from its surface to
  the corona obtained with the Solar and Heliospheric Observatory (SOHO)
  and Transition Region and Coronal Explorer (TRACE) show a ubiquitous
  sequence of events that start from cancellation of photospheric magnetic
  fields, pass through shock formation, and result in transition region
  supersonic jets and microflares. These results support a novel view of
  the energy buildup in the solar atmosphere associated with a cascade
  of shock waves produced by interacting network magnetic elements
  in the photosphere and provide insight into the origin of the solar
  transition region. The findings account for the general mechanisms
  of energy production, transfer, and release throughout the Sun's and
  stellar atmospheres.

Title: Interaction and Dynamics of the Photospheric Network Magnetic
    Elements
Authors: Ryutova, M.; Tarbell, T. D.; Shine, R.
Bibcode: 2003SoPh..213..231R
Altcode:
  Small-scale magnetic elements in the quiet photospheric network are
  believed to play a key role in the energy flow from the solar surface
  to upper layers of atmosphere. Their intense hydro-magnetic activity
  includes merging and fragmentation of same polarity fluxes, `total'
  or partial cancellation of neighboring flux elements of opposite
  polarity, dynamic appearance and disappearance of compact bipoles,
  etc. We study the general features of these processes, and show
  that non-collinearity of flux tubes, sharp stratification of low
  atmosphere and finite plasma beta lead to several specific effects
  in the interacting flux tubes that may explain the morphological
  properties of network magnetic field and also provide a mechanism
  for the energy build up and release in the nearby chromosphere and
  transition region. We show that during the collision of flux tubes in
  the photosphere reconnection occurs regardless of whether the flux
  tubes are of opposite or of the same polarity. But the dynamics of
  reconnection products are significantly different and lead to different
  macroscopic effects that can be observed.

Title: Estimating the Effects of JPEG Compression and Radiation on
    the Accuracy of Vector Magnetic Fields Measurements for Solar-B
Authors: Lites, B.; Shine, R. A.; López Ariste, A.; Tarbell, T. D.
Bibcode: 2002AGUFMSH52A0471L
Altcode:
  The Japanese Solar-B satellite, currently scheduled for launch in
  September 2005, includes a spectro-polarimeter (SP) to precisely measure
  the full Stokes polarization vector (I,Q,U,V) in the Fe I lines at
  6302Å. These will be processed to produce vector magnetograms of the
  solar surface using algorithms based on those for the Advanced Stokes
  Polarimeter (ASP) as described in Skumanich, et al, 1997, ApJ Suppl
  110. Accumulations of the raw images into time averaged I,Q,U,V images
  will be done on board and the results will be 12 bit JPEG compressed to
  make the best use of the available telemetry. Hence a single radiation
  hit in a raw image affects the entire time average at that point. Also,
  radiation spikes affect JPEG compression performance. Because of
  concerns about these effects, we simulated them separately and in
  combination using ASP data and radiation level measurements from the
  TRACE satellite. Like TRACE, Solar-B will fly in a high inclination,
  sun synchronous orbit and be exposed to radiation from the polar
  radiation belts as well as the SAA. Since the SP detector will be
  better shielded than that on TRACE, we hope that these will be an over
  estimate of the effects. The results from the simulations are very
  encouraging. We find that for active region magnetic fields we can use
  JPEG to compress the data volume by more than a factor of 10 without
  compromising the accuracy of the inferred magnetic field vector. The
  radiation in the polar regions has little effect and even the much
  stronger SAA radiation causes average perturbations that are less than
  the formal errors for sunspot fields and about twice the formal errors
  for plage fields. However, very weak field measurements will benefit
  from less lossy compression and periods of low radiation. Of course,
  the very strong radiation hits always produce artifacts. Compression
  performance is affected only slightly so it will not be necessary to
  avoid observations in the SAA because of excessive telemetry usage. This
  work was supported by NASA contract NAS8-01002.

Title: Correlations on Arcsecond Scales Between Chromospheric and
    Transition Region Structures in Active Regions
Authors: de Pontieu, B.; Tarbell, T.
Bibcode: 2002AGUFMSH52A0439D
Altcode:
  The discovery of active region moss, i.e, dynamic and bright upper
  transition region emission at chromospheric heights above active
  region (AR) plage, provides a powerful diagnostic to probe the
  structure, dynamics, energetics and coupling of the magnetized
  solar chromosphere and transition region (TR). Here we present an
  observational study of the interaction of the chromosphere with the
  TR moss, by studying correlations (or lack thereof) between emission
  at varying temperatures: from the low chromosphere (Ca II K-line),
  to the middle and upper chromosphere (wings of Hα), to the low
  transition region (C IV 1550 Å~at 0.1 MK), and the upper transition
  region (Fe IX/X 171 Å~at 1 MK and Fe XII 195 Å~at 1.5 MK). We use
  several datasets at high cadence (24 to 42 seconds) obtained with the
  Swedish Vacuum Solar Telescope (SVST, La Palma) and the Transition
  Region and Coronal Explorer (TRACE). This correlation analysis from
  low chromosphere to upper TR in AR plage quantifies and considerably
  expands on previous studies. Our results elucidate various issues,
  such as: 1. how the heating mechanisms of the chromosphere and lower
  and upper transition region are related (if at all), 2. how important
  heating of spicular jets is for the energy balance of the lower TR,
  3. the occurrence of significant periodic activity at all levels of the
  transition region and its coherence over a wide range of temperatures,
  4. which time scales dominate the dynamic behavior of the AR transition
  region, and, 5. whether the spatial and temporal variability of moss
  can be used as a diagnostic for coronal heating.

Title: Photospheric Magnetic Activities Responsible for Soft
    X-Ray Pointlike Microflares. I. Identifications of Associated
    Photospheric/Chromospheric Activities
Authors: Shimizu, T.; Shine, R. A.; Title, A. M.; Tarbell, T. D.;
   Frank, Z.
Bibcode: 2002ApJ...574.1074S
Altcode:
  By combining Yohkoh soft X-ray images with high-resolution magnetograms
  simultaneously obtained at La Palma, we studied photospheric magnetic
  signatures responsible for soft X-ray microflares (active-region
  transient brightenings). In order to have a reliable correspondence
  between the photosphere and the corona, we studied 16 pointlike
  transient brightenings with X-ray source size less than 10" occurring
  during periods when the seeing was excellent at La Palma, although a
  lot of transient brightenings were in forms of multiple- or single-loop
  structures. In half of the studied events, small-scale emergences
  of magnetic flux loops are found in the vicinity of the transient
  brightenings. Six events of that half show that a small-scale flux
  emergence accompanies the X-ray brightening 5-30 minutes prior to
  its onset. In the other half of the studied events, no apparent
  evolutionary change of magnetic flux elements is found associated
  with the transient brightenings. Many of these events are found in
  rather strong magnetic fields, such as sunspots and pores, implying
  that small-scale changes of magnetic flux are obscured or suppressed
  by strong magnetic fields. The horizontal plasma flows derived from
  local cross-correlation tracking of granules in continuum images are
  suppressed at the feet of some X-ray transient brightenings.

Title: Extreme Ultraviolet Flux and Sensitivity Changes in TRACE
    Images
Authors: Tarbell, T. D.; Nightingale, R. W.
Bibcode: 2002AAS...200.5504T
Altcode: 2002BAAS...34..732T
  During the TRACE mission, the sensitivity of the instrument in both
  UV and EUV channels has changed. This was expected from pre-flight
  measurements of the effects of EUV flux on a lumogen-coated CCD detector
  similar to the TRACE flight CCD. A mission-long record of EUV flux
  on the CCD has been maintained using low-resolution ``dosimeter''
  images. The correlations between EUV flux and UV sensitivity suggest
  that most of the change can be attributed to the detector and not to
  reductions in optical throughput. The techniques for UV calibration
  described in our accompanying poster have not been successful for the
  EUV channels. The Kuhn-Lin algorithm for deriving flat fields fails
  due to the very high contrast and temporal variability of TRACE EUV
  images. The synoptic images have not yet yielded useful information
  either, due to low fluxes in quiet sun and intermittency and variability
  among active regions. However, it is possible to measure the relative
  EUV sensitivity at different positions on the detector throughout
  the mission, using images of the same active region at different
  pointings. By comparing these with the dosimeter images and UV results,
  a preliminary calibration of sensitivity changes and flat fields in
  171 Å and 195 Å have been derived. Examples of corrected images
  are shown. This work was supported by the TRACE project at LMSAL
  (contract NAS5-38099).

Title: Active Region Moss as a Diagnostic for the Thermal Evolution
    of Chromospheric Spicule-Like Jets, and for Coronal Heating.
Authors: De Pontieu, B.; Tarbell, T.
Bibcode: 2002AAS...200.8807D
Altcode: 2002BAAS...34..790D
  The recent discovery of active region moss, i.e, dynamic and bright
  upper transition region emission at chromospheric heights above active
  region plage, provides a powerful diagnostic to probe the structure,
  dynamics, energetics and coupling of the magnetized solar chromosphere
  and transition region. Here we present an observational study of the
  interaction of the chromosphere with the TR moss, using a 2 hour
  time sequence of high-cadence (30 s) TRACE C IV 1550 Å (0.1 MK),
  Fe IX/X 171 Å (1 MK) and Fe XII 195 Å (1.5 MK) images, as well as
  co-aligned, simultaneous SUMER spectra, and ground-based filtergrams
  from the Swedish Vacuum Solar Telescope (SVST, La Palma) in the wings
  of H-alpha. Detailed comparisons of the H-alpha filtergrams (at -700,
  -350, +350 and +700 mÅ) with the TRACE C IV images reveals that there
  is often a significant spatial correlation of the C IV emission with
  the highly redshifted fibril or spicule-like structures in H-alpha +700
  mÅ. The discovery and detailed quantitative study of this correlation
  promises to shed light on the long outstanding issue of what role
  chromospheric spicule-like jets play in the heating and momentum
  balance of the outer atmosphere. We have also quantitatively studied
  the auto-correlation and cross-correlation time-scales of moss using
  a time sequence of high cadence TRACE 171 Å and 195 Å images. In
  most of the active region moss patch we studied, we find that the
  emission of 1 and 1.5 MK plasma is highly correlated, but often with
  significant negative and positive time delays. Our results indicate that
  the footpoints of hot coronal loops seem to undergo frequent cooling
  and heating on time-scales of order fifteen minutes. By quantifying
  these variations we can shed light on the temporal variability and on
  the location of coronal heating in general.

Title: What Can We Learn about Magnetic Reconnection in the Solar
    Corona from Joint SOHO/MDI and TRACE Observations?
Authors: Saba, J. L. R.; Gaeng, T.; Tarbell, T. D.
Bibcode: 2002AAS...200.6809S
Altcode: 2002BAAS...34..756S
  High-resolution, high-cadence images from the Transition Region and
  Coronal Explorer (TRACE) together with high quality line-of-sight
  magnetograms from the Michelson Doppler Imager (MDI) on SOHO let
  us examine signatures of magnetic reconnection and attempt to infer
  associated physical parameters. Recently we analyzed joint TRACE UV and
  MDI magnetogram data for the rise phase of a two-ribbon, GOES M1 class
  flare from NOAA active region 9236 at 2000 Nov 23 23:28 UT. We estimated
  the magnetic reconnection rate from the change in the photospheric
  magnetic flux swept out by the evolving 1600 Å-band flare ribbons. For
  simple assumptions with standard coronal parameters, the reconnection
  appeared to be fast, with the inferred inflow velocity a significant
  fraction of the Alfvén velocity. We extend our analysis to the peak
  and decay phases of that event, and consider other reconnection events
  observed jointly by TRACE and MDI, with guidance from coronal imaging
  of the reconnection region by the SOHO/EUV Imaging Telescope or the
  Yohkoh/Soft X-ray Telescope when not available from TRACE, and from
  extrapolation of the MDI magnetograms. We look for correlations of,
  e.g., the local reconnection rate with the instantaneous, peak, and
  integrated intensities and the time rate of change of intensity of the
  flare ribbons as a check on our analysis. The TRACE 1600 Å intensity
  includes contributions from both chromospheric and transition region
  (C IV) emission; it should be a proxy for the energy transmitted to the
  lower atmosphere and perhaps correlated with the total energy released
  by reconnection in the corona. This work is supported by NASA contracts
  NAG5-10483 (MDI) and NAS5-38099 (TRACE).

Title: Ultraviolet Flat Fields, Sensitivity Changes, and Their
    Removal from TRACE Images
Authors: Nightingale, R. W.; Tarbell, T. D.
Bibcode: 2002AAS...200.5505N
Altcode: 2002BAAS...34..732N
  As of April 1, 2002, the TRACE instrument has been in orbit for 4
  years. During this time the lumogen phosphor coating on the CCD has
  degraded due to the flux of extreme ultraviolet (EUV) photons. Flat
  field images have been obtained for the UV 1700 Å, 1216 Å,
  and broad-band white light (WL) channels. Normalized flat field
  responses have been calculated for each of these channels throughout
  the mission to date. Recent 1700 Å images show up to about a 30 %
  reduction in sensitivity near the center of the CCD relative to the
  edges. Analyzing these flat fields together with the synoptic disk
  center images throughout the mission, the flat fields and sensitivity
  changes over time for all 5 UV channels have been determined. The
  1700 Å flat field images serve as the basis for the lumogen loss
  corrections in all UV channels (but not WL). A set of time dependent
  power and multiplier parameters have been determined from fitting
  these flat fields to the mission synoptic data for the various UV
  wavelengths. The WL flat field images have not changed within +/- 1.5
  % over the mission to date. The WL flat fields are also used in the
  corrections for all UV images, to remove small artifacts intrinsic
  to the CCD and dust shadows common to certain channels. All these
  corrections have been implemented as an update into the SolarSoft (SSW)
  routine TRACE_PREP.PRO, and normally are automatically applied to the
  images after the dark pedestal and current corrections. Examples of
  these corrections applied to images over time will be presented. This
  work was supported by the TRACE project at LMSAL (contract NAS5-38099).

Title: A Study of Magnetic Reconnection using Simultaneous SOHO/MDI
    and TRACE Data
Authors: Saba, J. L. R.; Gaeng, T.; Tarbell, T. D.
Bibcode: 2002mwoc.conf..175S
Altcode:
  High-resolution, high-cadence images from the Transition Region and
  Coronal Explorer (TRACE) together with high quality magnetograms from
  the Michelson Doppler Imager (MDI) on SOHO let us examine signatures
  of magnetic reconnection and attempt to infer associated physical
  parameters such as the electric field strength in the corona. We
  analyzed TRACE UV and MDI magnetogram data for a two-ribbon, GOES
  M1-class flare from NOAA active region 9236 at 2000 Nov 23 23:28 UT,
  with emphasis on the dynamical development of the flare ribbons in
  the TRACE images. To estimate the rate of magnetic reconnection,
  we chose two obvious flare ribbons which grew rapidly in the first
  290-second sequence of high-cadence 1600Å flare response images. These
  ribbons could be separated with a simple binary mask from ejecta
  and other emission. They were located on strong fields of opposite
  polarity and grew rapidly, then faded away in place. This suggests
  that the emission was low in the atmosphere and well-aligned with the
  photospheric footpoints of fieldlines reconnecting in the corona. Thus
  we assume that the reconnection rate can be determined from the changing
  photospheric magnetic flux swept out by the evolving ribbon mask. The
  reconnection rate is very noisy, with a correlation time of at most a
  few seconds. For simple assumptions with standard coronal parameters
  (B ~ 100 G, n<SUB>p</SUB> ~ 3 times 10<SUP>9</SUP>, m cm<SUP>-3</SUP>
  near a strong sunspot), the reconnection appears to be fast, with
  the inferred inflow velocity a significant fraction of the Alfven
  velocity. Some guidance from coronal imaging of the reconnection region
  or Doppler measurement of inflow is needed to sharpen the constraints
  on the length of the reconnecting current sheet and the strength of
  the coronal electric field. This work was supported by NASA contracts
  NAG5-8878, NAG5-10483 (MDI) and NAS5-38099 (TRACE).

Title: Solar magnetic reconnection viewed with TRACE and SOHO/MDI
Authors: Saba, J.; Gaeng, T.; Tarbell, T.
Bibcode: 2002cosp...34E2811S
Altcode: 2002cosp.meetE2811S
  We combine high-resolution, high-cadence images from the Transition
  Region and Coronal Explorer (TRACE) with high quality line-of-sight
  magnetograms from the Michelson Doppler Imager (MDI) on SOHO to
  examine signatures of solar magnetic reconnection and attempt
  to infer associated physical parameters. We estimate the coronal
  magnetic reconnection rate from the change in the photospheric
  magnetic flux swept out by the evolving flare ribbons. For the first
  event studied - a two-ribbon, GOES M1 class flare from NOAA active
  region 9236 near central meridian on 2000 Nov 23 23:28 UT - we found
  that the reconnection appeared to be fast, with the inferred inflow
  velocity a significant fraction of the Alfvén velocity, assuming
  standard coronal parameters and a simple geometry for the reconnecting
  region. We consider other events and use (a) coronal imaging of the
  reconnection region (as available from TRACE, the SOHO/EUV Imaging
  Telescope, or the Yohkoh/Soft Xray Telescope), (b) extrapolation of
  the photospheric magnetograms, and (c) correlative studies of the
  reconnection rates with ribbon intensities, to check our assumptions
  and assess the uncertainties of our results. This work is supported
  by NASA contracts NAG5-10483 (MDI) and NAS5-38099 (TRACE).

Title: On the Correlation between Coronal and Lower Transition Region
    Structures at Arcsecond Scales
Authors: Vourlidas, A.; Klimchuk, J. A.; Korendyke, C. M.; Tarbell,
   T. D.; Handy, B. N.
Bibcode: 2001ApJ...563..374V
Altcode:
  We compare the morphology of active region structures observed in
  the 171 Å (T~9×10<SUP>5</SUP> K) and Lyα (T~2×10<SUP>4</SUP> K)
  lines. The coronal data were obtained by the Transition Region and
  Coronal Explorer (TRACE) in support of the Very High Angular Resolution
  Ultraviolet Telescope (VAULT) sounding rocket launch, which acquired
  subarcsecond resolution images of an active region in the Lyα line,
  on 1999 May 7. Using a pair of calibrated, nearly simultaneous images,
  we find that: (i) a very good correlation exists between the Lyα and
  171 Å intensities in the TRACE moss regions, (ii) we can identify
  several identical structures in some (but not all) moss areas, and
  (iii) the correlations are greatly reduced at the footpoints of the
  171 Å large-scale loops. We derive a lower limit for the Lyα emission
  measure, under the assumption of effectively optically thin emission,
  and compare it to the 171 Å emission measure. As in previous studies,
  we find an excess of Lyα material compared to the amount expected
  for a thermal conduction-dominated corona-chromosphere transition
  region, even for structures that appear to be identical in the two
  wavelengths. This result implies that some other mechanism besides
  classical heat conduction from the corona must contribute to the
  observed Lyα intensities. The observations do not support the idea
  of a physically distinct cool loop component within active regions.

Title: Dynamics of the solar chromosphere. III. Ultraviolet brightness
    oscillations from TRACE
Authors: Krijger, J. M.; Rutten, R. J.; Lites, B. W.; Straus, Th.;
   Shine, R. A.; Tarbell, T. D.
Bibcode: 2001A&A...379.1052K
Altcode:
  We analyze oscillations in the solar atmosphere using image sequences
  from the Transition Region and Coronal Explorer (TRACE) in three
  ultraviolet passbands which sample the upper solar photosphere and
  low chromosphere. We exploit the absence of atmospheric seeing in
  TRACE data to furnish comprehensive Fourier diagnostics (amplitude
  maps, phase-difference spectra, spatio-temporal decomposition) for
  quiet-Sun network and internetwork areas with excellent sampling
  statistics. Comparison displays from the ground-based Ca Ii H
  spectrometry that was numerically reproduced by Carlsson &amp;
  Stein are added to link our results to the acoustic shock dynamics
  in this simulation. The TRACE image sequences confirm the dichotomy
  in oscillatory behaviour between network and internetwork and show
  upward propagation above the cutoff frequency, the onset of acoustic
  shock formation in the upper photosphere, phase-difference contrast
  between pseudo-mode ridges and the interridge background, enhanced
  three-minute modulation aureoles around network patches, a persistent
  low-intensity background pattern largely made up of internal gravity
  waves, ubiquitous magnetic flashers, and low-lying magnetic canopies
  with much low-frequency modulation. The spatio-temporal occurrence
  pattern of internetwork grains is found to be dominated by acoustic
  and gravity wave interference. We find no sign of the high-frequency
  sound waves that have been proposed to heat the quiet chromosphere, but
  such measurement is hampered by non-simultaneous imaging in different
  passbands. We also find no signature of particular low-frequency
  fluxtube waves that have been proposed to heat the network. However,
  internal gravity waves may play a role in their excitation.

Title: Flow Map Studies of Supergranule and Mesogranule Evolution
    from TRACE
Authors: Shine, R. A.; Frank, Z. A.; Tarbell, T. D.; Simon, G. W.
Bibcode: 2001AGUFMSH11A0702S
Altcode:
  From 00:44 UT 22-April-2000 to 00:09 UT 29-April-2000 we obtained a
  nearly continuous set of white light images using the Transition Region
  and Corona Explorer (TRACE) satellite. A 384x384 arc second field of
  view was used that tracked solar rotation from Stonyhurst longitudes
  45E to 45W along the solar equator. The total time is nearly 7 days
  with images taken every minute over most of the interval. The largest
  temporal gap was 45m and there were only 9 gaps longer than 10m. The
  area was mostly free of active regions. These images are broad band
  white light with 0.5 arc second pixels. Granulation is well defined and
  we used local correlation techniques (LCT) to compute flow maps of the
  horizontal velocities with a resolution of about 5 arc seconds. The flow
  map resolution and quality suffer somewhat near the longitude extrema
  but the maps are usable throughout the 7 days to define supergranules
  and mesogranules. We compute horizontal divergence to study the motions
  of mesogranules and the evolution and lifetime of supergranules. When
  enough telemetry capacity was available, we also obtained co-spatial
  images in the TRACE Fe IX/X 171Å channel and the 1600Å channel. We
  use these to study the response of the corona and chromosphere to the
  photospheric motions. During times with particularly high telemetry
  throughput, we took white light images every 30 seconds. This allows
  us to empirically determine the noise in our flow maps using two
  interleaved and disjoint sets of white light data, each with one minute
  intervals. This work was supported by NASA contract NAS5-38099.

Title: A Study of Magnetic Reconnection Processes in Solar Active
    Regions using TRACE, MDI and EIT Data
Authors: Gaeng, T. E.; Saba, J.; Tarbell, T.
Bibcode: 2001AGUFMSH42A0779G
Altcode:
  We use high-resolution, high-cadence images from TRACE together with
  high quality magnetograms from SOHO/MDI and EUV images from SOHO/EIT
  to study signatures of magnetic reconnection and attempt to infer
  associated physical parameters such as the electric field strength
  in the corona. In this poster we present mainly results from the
  study of the GOES M1-class flare from NOAA active region 9236 at 2000
  Nov 23 23:28 UT, with emphasis on the dynamical development of the
  flare ribbons in the TRACE images. To estimate the rate of magnetic
  reconnection, we chose flare ribbons that could easily be separated
  with binary masks from ejecta and other emission by non-interactive
  IDL routines. The determined reconnection rate is very noisy, with
  a correlation time of at most a few seconds. For simple assumptions
  with standard coronal parameters (B ~ 100 G, n<SUB>p</SUB> ~ 3 x
  10<SUP>9</SUP> cm<SUP>-3</SUP> near a strong sunspot), the reconnection
  appears to be fast, with the inferred inflow velocity a significant
  fraction of the Alfven velocity. Estimates of the uncertainties of
  our measurements and analyses are derived from EIT images and simple
  potential field models. More guidance from coronal imaging of the
  reconnection regions or Doppler measurements of inflows are needed
  to sharpen the constraints on the length of the reconnecting current
  sheets and the coronal electric fields. This work was supported by
  NASA contracts NAG5-8878, NAG5-10483 (MDI) and NAS5-38099 (TRACE).
  &gt;http://chippewa.nascom.nasa.gov/gaeng/EOF-Science/&lt;/a&gt;

Title: Can the SOI/MDI Detect White Light Flares?
Authors: Gregory, S. E.; Myers, D.; Tarbell, T.; McIntosh, S.; Bush, R.
Bibcode: 2001AGUFMSH42A0765G
Altcode:
  We examine flares observed jointly with high spatial resolution by
  the SOHO instrument the Solar Oscillation Investigation/Michelson
  Doppler Imager (SOI/MDI) and the Transition Region and Coronal Explorer
  (TRACE). These include a GOES X1.1 class flare on 6 June 2000 and an
  X5.7 flare on 14 July 2000. The June flare data provide a unique set
  of line profiles across the flare site which help us better understand
  potential instrumental effects in the SOI/MDI response to flares. We
  locate the photospheric footpoints of the flares in both the SOI/MDI
  and TRACE intensity images and examine their relationship with the
  magnetograms. We also show that some flare kernels show emission in
  both the line and the continuum in SOI/MDI data.

Title: Precision spectro-polarimeter for high-resolution observations
    of solar magnetic fields
Authors: Lites, Bruce W.; Elmore, David F.; Streander, Kim V.; Akin,
   David L.; Berger, Tom; Duncan, Dexter W.; Edwards, Chris G.; Francis,
   Barbara; Hoffmann, Chris; Katz, Noah; Levay, Michael; Mathur, Dnyanesh;
   Rosenberg, William A.; Sleight, Ericka; Tarbell, Theodore D.; Title,
   Alan M.; Torgerson, Darrel
Bibcode: 2001SPIE.4498...73L
Altcode:
  As a Japanese National space mission with international collaboration,
  Solar-B (2005 launch) will carry a spectro- polarimeter (SP)
  to be operated in visible light to obtain the first high angular
  resolution, precision measurements of solar vector magnetic fields
  from space. The SP is part of the Focal Plane Package (FPP) fed by a
  diffraction-limited 50-cm optical telescope. The SP will be operated
  exclusively at the photospheric 630 nm Fe I lines. It features a
  rotating, low-order crystalline quartz retarder for polarization
  modulation and a reflecting Littrow spectrograph design that is
  shortened by using diffraction from the 12micrometers wide slit to
  fill the grating. Polarization analysis is accomplished by a modified
  Savart plate beam splitter. A custom CCD detector with two active
  areas, one for each beam from the beam splitter, allows continuous
  high duty-cycle sampling of polarization. The spectrograph slit will
  sample a 0.16 x 164 arcsec<SUP>2</SUP> rectangle of the solar image,
  which may be scanned across the slit by up to +/- 160 arcsec in order
  to build up vector magnetic field maps of the solar photosphere. Along
  with simultaneous, co-spatial imaging and polarimetry with the filter
  imagers of the FPP, the SP will provide a precise view of active and
  quiet solar magnetic fields that control the structure, dynamics,
  and energetics of the upper solar atmosphere.

Title: On the Magnetic Energy Avalanche in the Solar Atmosphere
Authors: Ryutova, M. P.; Tarbell, T. D.
Bibcode: 2001Ap&SS.277..153R
Altcode:
  We discuss a mechanism of energy production associated with the acoustic
  and MHD shocks produced by colliding and reconnecting flux tubes and
  present the observational results showing a connection between the
  dynamic changes in the photosphere and the high velocity and heating
  events in the transition region. We suggest that these processes may
  provide a constant energy supply for the origin of the fast wind and
  help to advance studies of coronal dynamics.

Title: A Study of Chromospheric Oscillations Using the SOHO and
    TRACE Spacecraft
Authors: Judge, Philip G.; Tarbell, Theodore D.; Wilhelm, Klaus
Bibcode: 2001ApJ...554..424J
Altcode:
  We analyze line and continuum time-series data of the solar atmosphere,
  with between 10 and 60 s cadence, using the MDI and SUMER instruments
  on the SOHO spacecraft and the UV bandpasses on the TRACE satellite. The
  co-aligned data sets sample spectral features formed from photosphere to
  the middle transition region, spanning five decades in pressure, under
  quiet-Sun and plage conditions. We discuss power, phase difference,
  and coherence spectra, and examine data in the time domain. The
  observed photospheric and chromospheric oscillations are strongly
  coupled for frequencies between 2 and 8 mHz. Phase coherences decrease
  with increasing height, with only occasional periods and locations of
  observable coherence up to heights where transition region emission
  lines are formed. The middle chromosphere (in the SUMER continua)
  oscillates in several megameter (Mm) diameter coherent patches
  with power predominantly in the 5-7 mHz range. The TRACE data,
  formed in the upper photosphere, show smaller patterns superimposed
  on these large-scale oscillations, resulting (at least in part)
  from granulation. At the observed spatial scales, all the observed
  properties point to p-modes, especially the ``pseudomodes'' just above
  the acoustic cutoff frequency, as the dominant mode of the chromospheric
  dynamics. Smaller scale ``acoustic event'' drivers, associated
  with granular dynamics, appear to be less important. The predominant
  internetwork chromospheric oscillations arise from regions much larger
  horizontally than vertically. If propagating largely vertically, this
  can naturally explain why the one-dimensional simulations of Carlsson
  &amp; Stein might be more successful than expected. The chromospheric
  response to the p-mode driving is, however, intermittent in space and
  time. Some of the intermittency appears to result from the interaction
  of the upward-propagating waves with magnetic fields. Evidence for this
  includes suppressed intensities and oscillations near quiet-Sun network
  elements (which we dub ``magnetic shadows''), absence of oscillations
  in internetwork regions neighboring plage magnetic fields, and a change
  in character of the quiet-Sun internetwork oscillations between the
  119 and 104 nm continua formed at 1 and 1.2 Mm. The latter might be
  caused by canopy fields that form between these heights under typical
  quiet-Sun conditions. A SUMER-only data set reported by Wikstøl et
  al. has a factor of 3 more oscillatory power in the 104 nm continuum
  than the data analyzed here, with stronger coherences extending into
  the solar transition region. Together, these data support the general
  picture that the chromosphere oscillates primarily in response to
  forcing by the p-modes, they are therefore large-scale (several Mm
  across) waves, and they are often strongly influenced by magnetic
  effects (internetwork fields, or the overlying canopy), before the
  oscillations even reach the transition region.

Title: Measurements of Magnetic Reconnection Rates and Inferred
    Coronal Electric Fields in Solar Active Regions from Simultaneous
    SOHO/MDI and TRACE observations
Authors: Gaeng, T.; Saba, J.; Tarbell, T.
Bibcode: 2001AGUSM..SH41A08G
Altcode:
  One of the long-standing issues in coronal physics is the lack of
  solid constraints on parameters that are fundamental to realistic
  models of magnetic reconnection. For example, the electric field
  strength above solar active regions is generally unknown, although it
  has been estimated to about a factor of two (Forbes and Lin 2000) in a
  specific large flare (Poletto and Kopp 1986). Recently, high resolution
  high cadence UV and EUV observations from the Transition Region and
  Coronal Explorer (TRACE) together with high quality magnetograms from
  the Michelson Doppler Imager (MDI) on SOHO provide an opportunity
  to approach this problem. These observations allow measuremenents
  of the rate of magnetic reconnection, which may be converted (using
  simple geometric models of the coronal fields) to electric fields
  in the reconnection region. We use the MDI and TRACE data archives
  to choose simultaneous TRACE observations and MDI high-resolution
  magnetograms of active regions near disk center. We create movies
  with these data to investigate reconnection rates in various coronal
  transient events. Some earlier La Palma high resolution observations
  in H-alpha showing reconnection rates may also be presented. This work
  was supported by NASA contracts NAG5-8878 (MDI) and NAS5-38099 (TRACE).

Title: Photospheric Network as the Energy Source for the quiet-Sun
    corona
Authors: Ryutova, M.; Habbal, S.; Woo, R.; Tarbell, T.
Bibcode: 2001SoPh..200..213R
Altcode:
  We propose a mechanism for the formation of a magnetic energy avalanche
  based on highly dynamic phenomena within the ubiquitous small-scale
  network magnetic elements in the quiet photosphere. We suggest that
  this mechanism may provide constant mass and energy supply for the
  corona and fast wind. Constantly emerging from sub-surface layers,
  flux tubes collide and reconnect generating magneto-hydrodynamic shocks
  that experience strong gradient acceleration in the sharply stratified
  photosphere/chromosphere region. Acoustic and fast magnetosonic
  branches of these waves lead to heating and/or jet formation due to
  cumulative effects (Tarbell et al., 1999). The Alfvén waves generated
  by post-reconnection processes have quite a restricted range of
  parameters for shock formation, but their frequency, determined by the
  reconnection rate, may be high enough (ω≃0.1-2.5 s<SUP>−1</SUP>)
  to carry the energy into the corona. We also suggest that the primary
  energy source for the fast wind lies far below the coronal heights, and
  that the chromosphere and transition region flows and also radiative
  transient form the base of the fast wind. The continuous supply of
  emerging magnetic flux tubes provides a permanent energy production
  process capable of explaining the steady character of the fast wind
  and its energetics.

Title: The Focal Plane Package for the Solar Optical Telescope
    on Solar-B
Authors: Tarbell, T.
Bibcode: 2001AGUSM..SH31D01T
Altcode:
  Solar-B is a Japanese space science mission of the Institute of
  Space and Astronautical Sciences (ISAS), with major participation of
  US and UK research groups. The mission includes the 50-cm aperture
  Solar Optical Telescope (SOT), with its Focal Plane Package (FPP)
  designed for high resolution photospheric and chromospheric imaging
  and spectro-polarimetry. There are also two coronal instruments, the
  X-Ray Telescope and Extreme-ultraviolet Imaging Spectrometer. Solar-B
  will be launched into a Sun-synchronous polar orbit in August,
  2005. The SOT is provided by ISAS and is being built by the National
  Astronomical Observatory of Japan (NAOJ) and Mitsubishi Electric
  Co. A team of Lockheed Martin, High Altitude Observatory (HAO), and
  NAOJ scientists and engineers are designing the FPP instrument. This
  talk gives an overview of the science goals of the FPP as well as
  the current instrument design and performance characteristics. The
  primary goal is to understand the coupling between the fine magnetic
  structures in the photosphere and dynamic processes and heating
  in the chromosphere and corona. The FPP consists of a narrow-band
  tunable birefringent filter imager, broad-band interference filter
  imager, and spectro-polarimeter (SP), essentially a space version
  of the HAO Advanced Stokes Polarimeter. The image is stabilized by a
  correlation tracker and active tilt mirror. The SP makes vector magnetic
  measurements from Stokes spectra of the Fe I lines 630.1 and 630.2 nm,
  with 0.16 arcsec pixels and field of view up to 164 x 328 arcsec. The
  broad-band system takes diffraction-limited images (0.05 arcsec pixels)
  in the Ca II H line, CN and G bandheads, and continuum bands. The
  narrow-band system makes filtergrams, magnetograms, Dopplergrams, and
  Stokes images in several photospheric lines, Mg b, and H-alpha. It has
  0.08 arcsec pixels and field-of-view same as that of the SP. The SP and
  filter imagers will usually observe simultaneously on the same target
  region. High-level observing sequences and coordination with the other
  instruments will be managed by FPP science planners, similar to those
  of SXT and TRACE. The FPP project is supported by NASA (NAS8-01002).

Title: Energy Distribution of Solar Oscillation Modes Inferred from
    Space-Based Measurements
Authors: Woodard, M. F.; Korzennik, S. G.; Rabello-Soares, C.; Kumar,
   P.; Tarbell, T. D.; Acton, S.
Bibcode: 2001AGUSM..SP21C05W
Altcode:
  We have measured the energy distribution of solar p- and f-mode
  oscillations of angular degree and temporal frequency in the range
  100&lt;l&lt;800 and 2&lt;ν (mHz)&lt;4 using helioseismology data from
  the SOI/MDI instrument on the SOHO satellite. At temporal frequency ν
  ≈ 3 mHz, the surface velocity power per oscillation mode increases
  slightly with angular degree between l = 100 and l=200, but decreases
  rather steeply with l above l=200, in approximate agreement with
  earlier findings from ground-based measurements. From this we infer
  that the time-averaged energy per mode, which is theoretically related
  to the modal surface velocity power, decreases steeply with l at fixed
  frequency, over the entire observed l range. Specifically, at ν =3.1
  mHz the energy per mode drops by a factor of ≈ 10 between l=150 and
  l=650, a circumstance not quantitatively understood at present. This
  research was supported by NASA and Stanford University.

Title: Intercomparison of SOUP, ASP, LPSP, and MDI magnetograms
Authors: Berger, T.; Lites, B.; Martinez-Pillet, V.; Tarbell, T.;
   Title, A.
Bibcode: 2001AGUSM..SP51B12B
Altcode:
  We compare simultaneous magnetograms of a solar active region taken by
  the Advanced Stokes Polarimeter (ASP) and the Solar Optical Universal
  Polimeter (SOUP) in 1998. In addition we compare magnetograms taken by
  the La Palma Stokes Polarimeter (LPSP), the Michelson Doppler Imager
  (MDI) on SOHO, and the SOUP instrument in 2000. The SOUP instrument on
  the Swedish Vacuum Solar Telescope (SVST) attains the highest spatial
  resolution but has the least understood calibration; the ASP on the Dunn
  Solar Telescope (DST) at Sacramento Peak attains the highest magnetic
  field precision. The goal of the program is to better quantify the
  SOUP magnetograms and thereby study magnetic element dynamics in the
  photosphere with higher precision.

Title: Formation of Compact Coronal Structures Associated with the
    Emerging Magnetic Flux
Authors: Ryutova, M. P.; Shine, R.; Tarbell, T. D.
Bibcode: 2001AGUSM..SH32C01R
Altcode:
  We study the events associated with the emergence of magnetic flux
  in the photosphere occurring throughout the solar atmosphere from
  its surface up to the low corona using coordinated observations from
  Swedish Vacuum Solar Telescope (SVST) on La Palma, the TRACE satellite
  and the MDI instrument on SOHO. The object of the observations is a
  plage dominated initially (UT 08:01:03, June 10, 1999) by positive
  polarity elements with about 0.3 magnetic filling factor near the
  same polarity sunspot. High resolution MDI magnetograms are assembled
  in a 6-hour movie and co-aligned with TRACE Fe IX/X 171 Å images of
  the corona, SVST Ca II K-line images showing the low chromosphere and
  Hα filtergrams showing plasma motions higher in the chromosphere. To
  study line of sight motions, we used filtergrams taken in the +/- 350
  ~mÅ (and +/- 700 ~mÅ) wings of Hα . During the first two hours,
  there are almost no changes (at the MDI resolution) in the initial
  magnetic field pattern of studied region, and the 171 Å emission
  above this region shows stable amorphous structures. Then a series of
  events lead to the formation of two opposite polarity pores in the
  target region and compact coronal loops above it with the following
  chronology. First, opposite polarity small-scale flux tubes emerge
  and interact with the existing plage elements. This is followed almost
  immediately by strong Hα surges, whose peak activity lasts about 10
  minutes. After this lag, enhanced emission in 171 Å takes the form
  of a short-lived transient. During the next one hour (long before
  the pore and compact coronal loops form), there are several new Hα
  surges and coronal plasma jets whose activity correlates well with
  remarkable changes in the photospheric fluxes which eventually form
  pores. For a quantitative analysis we apply a theoretical model of
  energy transport from subsurface motions associated with the emerging
  magnetic flux. Strong disturbances generated in a limited surface
  area may propagate upward like blast waves along a cone. This in
  turn may cause a sequence of phenomena associated with forward and
  reflected shocks, whose signatures are similar to the observations. The
  process may last as long as significant changes in the photospheric
  magnetic field occur, until it is suppressed by the strong fields in
  the pores. Under some condition the established pore structure may
  be accompanied by a current drive which leads to formation of the
  coronal loops.

Title: Diffraction Pattern Analysis of Bright TRACE Flares
Authors: Lin, Andrew C.; Nightingale, Richard W.; Tarbell, Theodore D.
Bibcode: 2001SoPh..198..385L
Altcode:
  A study of the diffraction patterns seen in TRACE images of bright
  flare kernels was undertaken to better understand the properties of
  the telescope. The diffraction pattern caused by light from a bright
  flare kernel passing through the mesh supporting the filters at the
  front of the TRACE telescope has been examined, and a method has been
  developed to use this pattern to determine the zeroth order intensity
  of flares that cannot be measured directly due to saturation of the
  Analog to Digital Converter (ADC) in the CCD detection package. The
  validity of this method is confirmed by testing it on a flare that
  does not saturate the ADC. The diffraction pattern allows us to
  measure intensities far brighter than the detection package allows;
  the range has been effectively increased by at least 41 times. The light
  scattered from any point was observed to be ≈20%, a significant amount
  which may be affecting the image quality of the telescope. An accurate
  determination of the ratio of the square slit size to slit spacing of
  the wire mesh was obtained. Wavelength dispersion, the phenomenon that
  as the higher-order diffracted peaks lie further from the center, they
  spread out until double peaks are observed, has also been examined. This
  effect is caused by two principal wavelengths, Fe ix at 171.073 Å and
  Fe x at 174.507 Å in the TRACE 171 Å passband. This study is a part
  of the TRACE Team educational outreach program.

Title: An Observational Manifestation of Magnetoatmospheric Waves
    in Internetwork Regions of the Chromosphere and Transition Region
Authors: McIntosh, S. W.; Bogdan, T. J.; Cally, P. S.; Carlsson, M.;
   Hansteen, V. H.; Judge, P. G.; Lites, B. W.; Peter, H.; Rosenthal,
   C. S.; Tarbell, T. D.
Bibcode: 2001ApJ...548L.237M
Altcode:
  We discuss an observational signature of magnetoatmospheric waves in
  the chromosphere and transition region away from network magnetic
  fields. We demonstrate that when the observed quantity, line or
  continuum emission, is formed under high-β conditions, where β is
  the ratio of the plasma and magnetic pressures, we see fluctuations in
  intensity and line-of-sight (LOS) Doppler velocity consistent with the
  passage of the magnetoatmospheric waves. Conversely, if the observations
  form under low-β conditions, the intensity fluctuation is suppressed,
  but we retain the LOS Doppler velocity fluctuations. We speculate that
  mode conversion in the β~1 region is responsible for this change in
  the observational manifestation of the magnetoatmospheric waves.

Title: Energy Distribution of Solar Oscillation Modes Inferred from
    Space-based Measurements
Authors: Woodard, M. F.; Korzennik, S. G.; Rabello-Soares, M. C.;
   Kumar, P.; Tarbell, T. D.; Acton, S.
Bibcode: 2001ApJ...548L.103W
Altcode:
  We have measured the energy distribution of solar p- and f-mode
  oscillations of angular degree and temporal frequency in the range
  100&lt;l&lt;800 and 2&lt;ν(mHz)&lt;4 using helioseismology data
  from the Solar Oscillations Investigation-Michelson Doppler Imager
  instrument on the Solar and Heliospheric Observatory satellite. At
  temporal frequency ν~3 mHz, the surface velocity power per oscillation
  mode increases slightly with angular degree between l=100 and l=200 but
  decreases rather steeply with l above l=200, in approximate agreement
  with earlier findings from ground-based measurements. From this we
  infer that the time-averaged energy per mode, which is theoretically
  related to the modal surface velocity power, decreases steeply with l,
  at fixed frequency, over the entire observed l-range. Specifically, at
  ν=3.1 mHz, the energy per mode drops by a factor of ~10 between l=150
  and l=650, a circumstance not quantitatively understood at present.

Title: In-flight performance of the Very high Angular resolution
    ULtraviolet Telescope sounding rocket payload
Authors: Korendyke, Clarence M.; Vourlidas, A.; Cook, John W.; Dere,
   Kenneth P.; Feldman, R.; Howard, Russell A.; Lilley, D. N.; Morrill,
   Jeff S.; Moses, J. Daniel; Moulton, Norman E.; Moye, Robert W.;
   Roberts, D. E.; Shepler, E. L.; Smith, J. K.; Socker, Dennis G.;
   Spears, T. R.; Waymire, R. S.; Brown, Wayne E.; Tarbell, Theodore D.;
   Berger, Tom; Handy, Brian N.
Bibcode: 2000SPIE.4139..340K
Altcode:
  The Very high Angular Resolution ULtraviolet Telescope experiment was
  successfully launched on May 7, 1999 on a Black Brant sounding rocket
  vehicle from White Sands Missile Range. The instrument consists of a
  30 cm UV diffraction limited telescope followed by a double grating
  spectroheliograph tuned to isolate the solar Lyman (alpha) emission
  line. During the flight, the instrument successfully obtained a series
  of images of the upper chromosphere with a limiting resolution of
  approximately 0.33 arc-seconds. The resulting observations are the
  highest resolution images of the solar atmosphere obtained from space
  to date. The flight demonstrated that subarc-second ultraviolet images
  of the solar atmosphere are achievable with a high quality, moderate
  aperture space telescope and associated optics. Herein, we describe
  the payload and its in- flight performance.

Title: On the Transition Region Explosive Events
Authors: Ryutova, M. P.; Tarbell, T. D.
Bibcode: 2000ApJ...541L..29R
Altcode:
  We describe the properties of high-velocity and explosive events in the
  solar transition region determined from time series of data taken by
  the Transition Region and Coronal Explorer and the SUMER instrument
  on the Solar and Heliospheric Observatory (SOHO) simultaneously in
  several chromospheric and transition region lines co-aligned with
  high-resolution Michelson Doppler Imager (SOHO) magnetograms. We
  outline what the various features of these events can tell us about
  the heating mechanisms and formation of plasma flows. Our results
  strongly support the mechanism of hydrodynamic cumulation of energy
  associated with the cascade of shock waves produced by colliding
  and reconnecting flux tubes in the photospheric network (as recently
  discussed by T. D. Tarbell et al.). We find that the majority of the
  explosive events are caused by the explosive instability occurring in
  the presence of the behind-shock downflows, and less than 10% can be
  explained by the direct collision of shock fronts.

Title: Time Variability of the ``Quiet'' Sun Observed with
    TRACE. I. Instrumental Effects, Event Detection, and Discrimination
    of Extreme-Ultraviolet Microflares
Authors: Aschwanden, Markus J.; Nightingale, Richard W.; Tarbell,
   Ted D.; Wolfson, C. J.
Bibcode: 2000ApJ...535.1027A
Altcode:
  The Transition Region and Coronal Explorer (TRACE) observed a
  ``quiet-Sun'' region on 1999 February 17 from 02:15 UT to 3:00 UT
  with full resolution (0.5" pixel size), high cadence (125 s), and deep
  exposures (65 and 46 s) in the 171 Å and 195 Å wavelengths. We start
  our investigation of the time variability of ``quiet-Sun'' images
  with a detailed analysis of instrumental and nonsolar effects, such
  as orbital temperature variations, filtering of particle radiation
  spikes, spacecraft pointing drift, and solar rotation tracking. We
  quantify the magnitude of various noise components (photon Poisson
  statistics, data digitization, data compression, and readout noise)
  and establish an upper limit for the data noise level, above which
  temporal variability can safely be attributed to solar origin. We
  develop a pattern recognition code that extracts spatiotemporal events
  with significant variability, yielding a total of 3131 events in 171 Å
  and 904 events in 195 Å. We classify all 904 events detected in 195 Å
  according to flarelike characteristics and establish a numerical flare
  criterion based on temporal, spatial, and dynamic cross-correlation
  coefficients between the two observed temperatures (0.9 and 1.4
  MK). This numerical criterion matches the visual flare classification
  in 83% of the cases and can be used for automated flare search. Using
  this flare discrimination criterion we find that only 35% (and 25%) of
  the events detected in 171 (and 195) Å represent flarelike events. The
  discrimination of flare events leads to a frequency distribution of
  peak fluxes, N(ΔF)~ΔF<SUP>-1.83+/-0.07</SUP> at 195 Å, which is
  significantly flatter than the distribution of all events. A sensitive
  discrimination criterion of flare events is therefore important for
  microflare statistics and for conclusions on their occurrence rate
  and efficiency for coronal heating.

Title: Time Variability of the ``Quiet'' Sun Observed with
    TRACE. II. Physical Parameters, Temperature Evolution, and Energetics
    of Extreme-Ultraviolet Nanoflares
Authors: Aschwanden, Markus J.; Tarbell, Ted D.; Nightingale, Richard
   W.; Schrijver, Carolus J.; Title, Alan; Kankelborg, Charles C.;
   Martens, Piet; Warren, Harry P.
Bibcode: 2000ApJ...535.1047A
Altcode:
  We present a detailed analysis of the geometric and physical
  parameters of 281 EUV nanoflares, simultaneously detected with the
  TRACE telescope in the 171 and 195 Å wavelengths. The detection and
  discrimination of these flarelike events is detailed in the first paper
  in this series. We determine the loop length l, loop width w, emission
  measure EM, the evolution of the electron density n<SUB>e</SUB>(t) and
  temperature T<SUB>e</SUB>(t), the flare decay time τ<SUB>decay</SUB>,
  and calculate the radiative loss time τ<SUB>loss</SUB>, the conductive
  loss time τ<SUB>cond</SUB>, and the thermal energy E<SUB>th</SUB>. The
  findings are as follows: (1) EUV nanoflares in the energy range of
  10<SUP>24</SUP>-10<SUP>26</SUP> ergs represent miniature versions
  of larger flares observed in soft X-rays (SXR) and hard X-rays
  (HXR), scaled to lower temperatures (T<SUB>e</SUB>&lt;~2 MK),
  lower densities (n<SUB>e</SUB>&lt;~10<SUP>9</SUP> cm<SUP>-3</SUP>),
  and somewhat smaller spatial scales (l~2-20 Mm). (2) The cooling
  time τ<SUB>decay</SUB> is compatible with the radiative cooling
  time τ<SUB>rad</SUB>, but the conductive cooling timescale
  τ<SUB>cond</SUB> is about an order of magnitude shorter, suggesting
  repetitive heating cycles in time intervals of a few minutes. (3)
  The frequency distribution of thermal energies of EUV nanoflares,
  N(E)~10<SUP>-46</SUP>(E/10<SUP>24</SUP>)<SUP>-1.8</SUP> (s<SUP>-1</SUP>
  cm<SUP>-2</SUP> ergs<SUP>-1</SUP>) matches that of SXR microflares
  in the energy range of 10<SUP>26</SUP>-10<SUP>29</SUP>, and exceeds
  that of nonthermal energies of larger flares observed in HXR by a
  factor of 3-10 (in the energy range of 10<SUP>29</SUP>-10<SUP>32</SUP>
  ergs). Discrepancies of the power-law slope with other studies, which
  report higher values in the range of a=2.0-2.6 (Krucker &amp; Benz;
  Parnell &amp; Jupp), are attributed to methodical differences in the
  detection and discrimination of EUV microflares, as well as to different
  model assumptions in the calculation of the electron density. Besides
  the insufficient power of nanoflares to heat the corona, we find also
  other physical limits for nanoflares at energies &lt;~10<SUP>24</SUP>
  ergs, such as the area coverage limit, the heating temperature limit,
  the lower coronal density limit, and the chromospheric loop height
  limit. Based on these quantitative physical limitations, it appears
  that coronal heating requires other energy carriers that are not
  luminous in EUV, SXR, and HXR.

Title: The Solar-B Focal Plane Package
Authors: Berger, T. E.; Title, A. M.; Tarbell, T. D.; Lites, B. W.;
   Elmore, D. F.
Bibcode: 2000SPD....31.0292B
Altcode: 2000BAAS...32..827B
  Solar-B is a Japanese national space science mission of the Institute
  of Space and Astronautical Sciences (ISAS) with participation from
  US and UK research groups. The satellite consists of a 50-cm optical
  telescope and Focal Plane Package (FPP) designed for high resolution
  photospheric and chromospheric imaging and spectro-polarimetry as
  well as two coronal instruments: the X-Ray Telescope (XRT) and the
  Extreme-ultraviolet Imaging Spectrometer (EIS). Solar-B will be
  launched into a Sun-synchronous orbit in August of 2004. A team of
  Lockheed Martin Solar and Astrophysics Laboratory (LMSAL), High Altitude
  Observatory, and ISAS personnel are designing the FPP instrument. It
  consists of a narrow-band tunable birefringent filter system,
  a wide band interference filter system, and a spectro-polarimeter
  system for very high sensitivity Stokes polarimetry, all of which
  will be fabricated at LMSAL. We describe the main science goals of
  the FPP as well as the current instrument design and performance
  characteristics. This work is supported by NASA contract NAS8-00014
  (Solar-B FPP).

Title: Instrumental Effects and their Removal from TRACE Images
Authors: Tarbell, T. D.; Nightingale, R. N.; Metcalf, T. R.; Frank,
   Z. A.; TRACE Team
Bibcode: 2000SPD....31.0291T
Altcode: 2000BAAS...32..827T
  TRACE raw images often show fine structures at such high contrast
  that compensation for instrumental effects is not necessary to study
  their morphology and evolution. Nevertheless, TRACE team members have
  gradually been developing the techniques and calibrations necessary
  to understand and (sometimes) remove the principal instrumental
  degradations. These degradations include CCD pedestal variation
  with temperature and time, flat-field response, CCD sensitivity loss
  varying with position and wavelength, electrical interference during
  CCD readout, permanent dim pixels, intermittent hot pixels, overall
  system point spread function, diffraction of EUV radiation by the front
  entrance filters, scattered light at off-limb pointings, tracks of
  electrons and protons from the radiation belts, and artifacts from JPEG
  compression of solar strucures and the above defects. Characterization
  and removal of some of these will be presented in the poster, such
  as the following. A deconvolution routine can partially compensate
  for the EUV diffraction, which is described in the adjacent poster by
  Frank et al. White light flat fields are derived using the Kuhn-Lin
  algorithm. CCD sensitivity degradation (presumably lumogen damage) is
  measured both from crude UV and EUV flat fields and from mission-long
  analysis of synoptic disk center images; combining these results with
  the WL flats yields flat fields at all wavelengths. Some information on
  scattered light and point spread functions are obtained from the August,
  1999, eclipse observations and the Mercury transit. SSW routines for
  dealing with some of these degradations will be identified. This work
  is supported by the TRACE project at LMSAL (contract NAS5-38099).

Title: Observation of Shocks in the Chromosphere and Transition Region
Authors: Ryutova, M. P.; Tarbell, T. D.
Bibcode: 2000SPD....31.0141R
Altcode: 2000BAAS...32..808R
  The spectra of CII and OVI lines corresponding to chromosphere and
  transition region temperatures show significant broadening and complex
  line profiles in regions overlying the sites of small scale magnetic
  elements in the photopsheric network. Doppler shifted multiple peaks
  in CII line are always seen soon after the reconnection of magnetic
  flux tubes occurs and usually consist of supersonic and subsonic
  components caused by shocks propagating upward. Multiple peaks in OVI
  line have more diverse features: they are not as persistent as those
  seen in CII line, and may have the configuration of maximum intensity
  peaks corresponding either to forward or reflected shocks. We develop
  a consistency analysis which allows to compare the shock relations
  and their properties with the observed signatures and infer physical
  parameters such as Mach number, direction of the shock propagation
  and velocities. We use the uninterrupted time series of data to trace
  particular events at the different stages of their evolution and deduce
  some intrinsic features of the mechanism of the energy production and
  its transport through the chromosphere/transition region.

Title: The STEREO-SECCHI Extreme Ultraviolet Imager
Authors: Wülser, J. -P.; Lemen, J. R.; Tarbell, T. D.; Wolfson,
   C. J.; Howard, R. A.; Moses, J. D.; Delaboudinière, J. -P.
Bibcode: 2000SPD....31.0294W
Altcode:
  The Extreme Ultraviolet Imager (EUVI) is part of the SECCHI
  investigation selected for flight on the STEREO mission. The twin EUVI
  telescopes on the two STEREO spacecraft will study the structure and
  evolution of the solar corona in three dimensions, and specifically
  focus on the initiation and early evolution of coronal mass ejections
  (CMEs). The EUVI's 2048 x 2048 pixel detectors will have a full sun
  field of view, and will observe in four spectral channels that cover
  the 0.1 to 2 MK temperature range. The EUVI's major advance is its
  view from two vantage points in space. It will allow it to investigate
  the structure of CMEs in three dimensions, while the EUVI's high image
  cadence capability will allow it to resolve the CME's initiation and
  early evolution.

Title: The STEREO-SECCHI extreme ultraviolet imager.
Authors: Wülser, J. -P.; Lemen, J. R.; Tarbell, T. D.; Wolfson,
   C. J.; Howard, R. A.; Moses, J. D.; Delaboudinière, J. -P.
Bibcode: 2000BAAS...32..827W
Altcode:
  No abstract at ADS

Title: Diffraction Pattern Analysis of Bright TRACE Flares
Authors: Frank, Z. A.; Lin, A. C.; Nightingale, R. W.; Tarbell, T. D.
Bibcode: 2000SPD....31.0290F
Altcode: 2000BAAS...32..827F
  A study of the diffraction patterns seen in TRACE images of bright
  flares was undertaken to better understand the properties of the
  telescope. The pattern caused by light from a bright solar flare passing
  through the wire mesh in front of the telescope has been examined, and
  a method has been developed to use this pattern to determine the zeroth
  order intensity of bright flares. This intensity cannot usually be
  measured directly due to saturation of the Analog to Digital Converter
  (ADC) electronics in the CCD camera package. The validity of this
  method has been tested on dimmer flares, whose intensity do not saturate
  the ADC. The diffraction pattern allows us to measure intensities far
  brighter than the camera package permits. For the bright flare on May
  16, 1999 at 13:49:21 UT the range has been effectively increased by at
  least 41 times. The light defracted away from any point was observed
  to be 18%, a significant amount which affects the contrast of TRACE
  images. An accurate determination of the ratio of the square slit
  size to slit spacing of the wire mesh has been obtained. This is an
  important parameter for a deconvolution routine that can remove the
  diffraction patterns from the image (see adjacent SPD poster paper
  by Tarbell et al.). Wavelength dispersion, the phenomenon that as the
  higher order diffracted peaks lie further from the center they spread
  out until double peaks are observed, has also been examined as part of
  this study. This effect is observable because there are two principal
  wavelengths, Fe IX at 171.06 Angstroms and Fe X at 174.52 Angstroms
  in the TRACE 171 Angstroms passband used in present analysis. This
  study is a part of the TRACE Team educational outreach program and is
  supported by contract NAS5-38099 at LMSAL.

Title: TRACE Observations of Footpoints, Connections and Loops
Authors: Tarbell, T. D.
Bibcode: 2000SPD....31.1303T
Altcode: 2000BAAS...32..845T
  The Transition Region and Coronal Explorer (a NASA Small Explorer
  mission) was launched in April, 1998, and began observing in May. Since
  launch, TRACE has performed nearly flawlessly and has collected over
  two million images of the Sun. TRACE was designed to collect images
  of all temperature domains of the solar atmosphere with high spatial
  resolution and high cadence. Its movie sequences of the transition
  region and corona have given us an unprecedented view of the dynamic
  activity of magnetic fields above the solar surface. Using powerful
  movie analysis software (the ANA browser), quantitative interactive
  study of large datacubes is possible within hours of receipt of the raw
  data. Since solar activity is increasing and since potential damage
  to the CCD detector by over-exposure is better understood now, TRACE
  devotes a large fraction of its observing time to flare watches. The
  full-sun orbit, circular data buffers, and generous telemetry allow
  TRACE to collect high cadence observations of preflare and flare
  conditions. This talk will show examples of interesting and beautiful
  TRACE observations of flares and less energetic coronal changes. The
  footpoints of loops involved can sometimes be identified from transient
  brightenings in the chromosphere and transition region. The inferred
  connectivity is compared with photospheric magnetograms and with loops
  seen in Fe IX/X 171 and Fe XII 195. This work is supported by the
  TRACE project at LMSAL (contract NAS5-38099) and the SOI/MDI project
  at Stanford and LMSAL (grant NAG5-3077).

Title: Electro-Mechanical Coupling Between the Photosphere and
    Transition Region
Authors: Tarbell, T. D.; Ryutova, M.; Shine, R.
Bibcode: 2000SoPh..193..195T
Altcode:
  We study the response of the chromosphere and transition region to
  dynamic changes in the photospheric network magnetic fields. We present
  results from simultaneous measurements taken by TRACE in chromospheric
  and transition region (C iv) images, high-resolution magnetograms taken
  by MDI, and spectra of chromospheric (C ii) and transition region
  lines (O vi) obtained with the SUMER instrument on SOHO. Enhanced
  emission in the C iv line is generally co-spatial with the magnetic
  pattern in the photosphere. We propose a mechanism of electro-mechanical
  coupling between the photosphere and upper layers of atmosphere based on
  hydrodynamic cumulation of energy produced by reconnecting flux tubes in
  the photosphere/chromosphere region (Tarbell et al., 1999). We believe
  that a basic process causing energetic events is the cascade of shock
  waves produced by colliding and reconnecting flux tubes. The continuous
  supply of flux tubes in the `magnetic carpet' ensures the ubiquitous
  nature of this process and its imprint on the upper atmosphere. The
  appearance of bright transients often, but not always, correlates with
  canceling mixed polarity magnetic elements in the photosphere. In
  other cases, transients occur in regions of unipolar flux tubes,
  suggesting reconnection of oblique components. Transients are also
  seen in regions with no fields detected with the MDI sensitivity;
  these may be reconnections of tiny features with diameters less than
  100 km. Blinkers and other bright transients are often accompanied by
  two directional plasma jets. These may be generated by cylindrical
  self-focusing of shock fronts or by collision of shocks produced by
  neighboring reconnection processes. The observations suggest that
  stronger emissions correspond to lower velocity jets, and vice versa;
  this property is a natural consequence of the proposed mechanism. Plasma
  flows are always seen whenever the slit crosses strong magnetic flux
  tubes or vertices of converging flows in the supergranular network. The
  overall energy distribution between heating and plasma flows is an
  intrinsic feature of our mechanism.

Title: Calibrated H I Lyman α Observations with TRACE
Authors: Handy, B. N.; Tarbell, T. D.; Wolfson, C. J.; Korendyke,
   C. M.; Vourlidas, A.
Bibcode: 1999SoPh..190..351H
Altcode:
  Since shortly after launch in April 1998, the Transition Region and
  Coronal Explorer (TRACE) observatory has amassed a collection of H
  i Lα (1216 Å) observations of the Sun that have been not only of
  high spatial and temporal resolution, but also span a duration in
  time never before achieved. The Lα images produced by TRACE are,
  however, composed of not only the desired line emission, but also
  local ultraviolet continuum and longer wavelength contamination. This
  contamination has frustrated attempts to interpret TRACE observations
  in H i Lα. The Very Advanced Ultraviolet Telescope (VAULT) sounding
  rocket payload was launched from White Sands Missile range 7 May 1999
  at 20:00 UT. The VAULT telescope for this flight was a dedicated H i
  Lα imaging spectroheliograph. We use TRACE observations in the 1216
  Å and 1600 Å channels along with observations from the VAULT flight
  to develop a method for removing UV continuum and longer wavelength
  contamination from TRACE Lα images.

Title: Simultaneous Observations of Chromospheric and Transition
    Region Oscillations in HI Lyman Transitions and in Optical Lines
Authors: Curdt, W.; Heinzel, P.; Schmidt, W.; Tarbell, T.; von
   Uexküll, M.; Wilken, V.
Bibcode: 1999ESASP.448..177C
Altcode: 1999mfsp.conf..177C; 1999ESPM....9..177C
  No abstract at ADS

Title: What is Moss?
Authors: Berger, T. E.; De Pontieu, B.; Fletcher, L.; Schrijver,
   C. J.; Tarbell, T. D.; Title, A. M.
Bibcode: 1999SoPh..190..409B
Altcode:
  TRACE observations of active regions show a peculiar extreme ultraviolet
  (EUV) emission over certain plage areas. Termed `moss' for its spongy,
  low-lying, appearance, observations and modeling imply that the
  phenomenon is caused by thermal conduction from 3-5 MKcoronal loops
  overlying the plage: moss is the upper transition region emission of
  hot coronal loops. The spongy appearance is due to the presence of
  chromospheric jets or `spicules' interspersed with the EUV emission
  elements. High cadence TRACE observations show that the moss EUV
  elements interact with the chromospheric jets on 10 s time scales. The
  location of EUV emission in the moss does not correlate well to the
  locations of underlying magnetic elements in the chromosphere and
  photosphere, implying a complex magnetic topology for coronal loop
  footpoint regions. We summarize here the key observations leading to
  these conclusions and discuss new implications for understanding the
  structuring of the outer solar atmosphere.

Title: Characteristics of MHD Oscillations Observed with MDI
Authors: Norton, A. A.; Ulrich, R. K.; Bush, R. I.; Tarbell, T. D.
Bibcode: 1999ASPC..184..136N
Altcode:
  We report on the spatial distribution of magnetic oscillatory power and
  phase angles between velocity and magnetic signals as observed with the
  Michelson Doppler Imager. The dataset is 151.25arcsec x 151.25arcsec
  containing sunspot from Dec 2, 1997 with a temporal sampling interval
  of 60 seconds and spatial sampling of 0.605arcsec. Simultaneously
  observed continuum intensity and surface velocity accompany the magnetic
  information. We focus on three frequency regimes: 0.5-1.0, 3.0-3.5 and
  5.5-6.0 mHz corresponding roughly to timescales of magnetic evolution,
  p-modes and the 3 minute resonant sunspot oscillation. Significant low
  frequency magnetic power is found in lower flux pixels, 100-300 Gauss,
  in a striking ring with filamentary structure surrounding sunspot. Five
  minute oscillatory magnetic power peaks in extended regions of flux
  600-800 Gauss. The 3 minute oscillation is observed in sunspot umbra
  in pixels whose flux measures 1300-1500 Gauss. Phase angles of -90°
  between velocity and magnetic flux in the 3.0-3.5 and 5.5-6.0 mHz
  regimes suggest the MHD oscillations are magnetoacoustic in nature.

Title: A new view of the solar outer atmosphere by the Transition
    Region and Coronal Explorer
Authors: Schrijver, C. J.; Title, A. M.; Berger, T. E.; Fletcher, L.;
   Hurlburt, N. E.; Nightingale, R. W.; Shine, R. A.; Tarbell, T. D.;
   Wolfson, J.; Golub, L.; Bookbinder, J. A.; DeLuca, E. E.; McMullen,
   R. A.; Warren, H. P.; Kankelborg, C. C.; Handy, B. N.; De Pontieu, B.
Bibcode: 1999SoPh..187..261S
Altcode:
  The Transition Region and Coronal Explorer (TRACE) - described in the
  companion paper by Handy et al. (1999) - provides an unprecedented
  view of the solar outer atmosphere. In this overview, we discuss the
  initial impressions gained from, and interpretations of, the first
  million images taken with TRACE. We address, among other topics,
  the fine structure of the corona, the larger-scale thermal trends,
  the evolution of the corona over quiet and active regions, the high
  incidence of chromospheric material dynamically embedded in the coronal
  environment, the dynamics and structure of the conductively dominated
  transition region between chromosphere and corona, loop oscillations
  and flows, and sunspot coronal loops. With TRACE we observe a corona
  that is extremely dynamic and full of flows and wave phenomena, in
  which loops evolve rapidly in temperature, with associated changes in
  density. This dynamic nature points to a high degree of spatio-temporal
  variability even under conditions that traditionally have been referred
  to as quiescent. This variability requires that coronal heating can
  turn on and off on a time scale of minutes or less along field-line
  bundles with cross sections at or below the instrumental resolution
  of 700 km. Loops seen at 171 Å (∼1 MK) appear to meander through
  the coronal volume, but it is unclear whether this is caused by the
  evolution of the field or by the weaving of the heating through the
  coronal volume, shifting around for periods of up to a few tens of
  minutes and lighting up subsequent field lines. We discuss evidence
  that the heating occurs predominantly within the first 10 to 20 Mm
  from the loop footpoints. This causes the inner parts of active-region
  coronae to have a higher average temperature than the outer domains.

Title: The transition region and coronal explorer
Authors: Handy, B. N.; Acton, L. W.; Kankelborg, C. C.; Wolfson, C. J.;
   Akin, D. J.; Bruner, M. E.; Caravalho, R.; Catura, R. C.; Chevalier,
   R.; Duncan, D. W.; Edwards, C. G.; Feinstein, C. N.; Freeland, S. L.;
   Friedlaender, F. M.; Hoffmann, C. H.; Hurlburt, N. E.; Jurcevich,
   B. K.; Katz, N. L.; Kelly, G. A.; Lemen, J. R.; Levay, M.; Lindgren,
   R. W.; Mathur, D. P.; Meyer, S. B.; Morrison, S. J.; Morrison, M. D.;
   Nightingale, R. W.; Pope, T. P.; Rehse, R. A.; Schrijver, C. J.;
   Shine, R. A.; Shing, L.; Strong, K. T.; Tarbell, T. D.; Title, A. M.;
   Torgerson, D. D.; Golub, L.; Bookbinder, J. A.; Caldwell, D.; Cheimets,
   P. N.; Davis, W. N.; Deluca, E. E.; McMullen, R. A.; Warren, H. P.;
   Amato, D.; Fisher, R.; Maldonado, H.; Parkinson, C.
Bibcode: 1999SoPh..187..229H
Altcode:
  The Transition Region and Coronal Explorer (TRACE) satellite, launched
  2 April 1998, is a NASA Small Explorer (SMEX) that images the solar
  photosphere, transition region and corona with unprecedented spatial
  resolution and temporal continuity. To provide continuous coverage
  of solar phenomena, TRACE is located in a sun-synchronous polar
  orbit. The ∼700 Mbytes of data which are collected daily are made
  available for unrestricted use within a few days of observation. The
  instrument features a 30-cm Cassegrain telescope with a field of view
  of 8.5×.5 arc min and a spatial resolution of 1 arc sec (0.5 arc sec
  pixels). TRACE contains multilayer optics and a lumogen-coated CCD
  detector to record three EUV wavelengths and several UV wavelengths. It
  observes plasmas at selected temperatures from 6000 K to 10 MK with
  a typical temporal resolution of less than 1 min.

Title: Magnetic energy avalanche as the source of the fast wind
Authors: Ryutova, M. P.; Habbal, S. R.; Woo, R.; Tarbell, T.
Bibcode: 1999AIPC..471..227R
Altcode: 1999sowi.conf..227R
  We propose a mechanism for the formation of a magnetic energy avalanche
  based on highly dynamic phenomena within the ubiquitous small scale
  network magnetic elements in the quiet photosphere. We suggest that
  this mechanism may provide constant mass and energy supply for the
  origin of the fast wind.

Title: Characteristics of Magnetohydrodynamic Oscillations Observed
    with the Michelson Doppler Imager
Authors: Norton, A. A.; Ulrich, R. K.; Bush, R. I.; Tarbell, T. D.
Bibcode: 1999ApJ...518L.123N
Altcode: 1999astro.ph..7256N
  We report on the spatial distribution of the magnetogram oscillatory
  power and the phase angles between velocity and magnetogram signals
  as observed with the Michelson Doppler Imager. The data set is
  151.25" × 151.25", containing the sunspot from 1997 December 2
  with a temporal sampling interval of 60 s and spatial sampling of
  0.605". The simultaneously observed continuum intensity and surface
  velocity accompany the magnetic information. We focus on three frequency
  regimes: 0.5-1.0, 3.0-3.5, and 5.5-6.0 mHz, corresponding roughly to
  timescales of magnetic evolution, p-modes, and the 3 minute resonant
  sunspot oscillation. Significant low-frequency magnetogram power
  is found in lower flux pixels, 100-300 G, in a striking ring with
  filamentary structure surrounding the sunspot. The 5 minute magnetogram
  power peaks in extended regions of flux that measure 600-800 G. The
  3 minute oscillation is observed in the sunspot umbra in pixels whose
  flux measures 1300-1500 G. Phase angles of approximately -90° between
  velocity and magnetic flux in the 3.0-3.5 and 5.5-6.0 mHz regimes are
  found in regions of significant cross amplitude.

Title: Heating and jet formation by colliding shocks in solar
    atmosphere
Authors: Tarbell, T.; Ryutova, M. P.; Covington, J.; Fludra, A.
Bibcode: 1999AIPC..471..419T
Altcode: 1999sowi.conf..419T
  We show that ubiquitous small-scale magnetic flux ``tubes''
  constantly emerging from subsurface layers, may cause the formation
  of plasma jets and a sporadic excess of temperature near the solar
  surface. Photospheric network magnetic elements collide and reconnect,
  creating a sling-shot effect which generates complex 3D shock waves
  with the curved surface. Self-focusing of these shocks occurs as they
  propagate upward in the rarefied atmosphere. Depending on the geometry
  of the shock collision, highly concentrated energy may be either
  converted entirely into heat or into strong jets, or be distributed
  between the two.

Title: A Transition Region Eruption Observed with CDS, TRACE and EIT
Authors: Brekke, P.; Kjeldseth-Moe, O.; Fredvik, T.; Haugan, S. V. H.;
   Tarbell, T. D.; Gurman, J. B.
Bibcode: 1999AAS...194.5905B
Altcode: 1999BAAS...31..918B
  An ejection of plasma on the west limb has been observed with CDS,
  TRACE and EIT on 19 May 1998. The start of the eruption coincided
  with a weak flare observed with GOES. Erupting material rose to 120
  Mm above the solar surface in 17 min, and then fell back to the solar
  surface. Vertical velocities of 200 km s(-1) are estimated from a series
  of TRACE images in the C(+3) resonance lines at 155 nm and from EIT
  images in the 19.5 nm band, while Doppler shifts of the transition
  region lines observed with CDS yield maximum horizontal velocities
  of 300 km s(-1) at the top of the plasma trajectories. The similar
  appearance and time variation of the eruption as seen with all three
  instruments indicate the presence of a multi-temperature plasma in
  spatial regions less than 1-2 arc seconds, with temperatures ranging
  from 10(5) K to 1.5 MK. The material did not have the momentum to break
  loose from the Sun and was not associated with any CME observed with
  LASCO. However, we may speculate that CMEs are similar to the eruption
  observed, with even higher speeds involved.

Title: TRACE Images of the Solar Chromosphere, Transition Region,
    and Low Corona at High Cadence and High Spatial Resolution
Authors: Tarbell, T. D.; Handy, B. N.; Judge, P. G.
Bibcode: 1999AAS...194.7801T
Altcode: 1999BAAS...31..960T
  We present TRACE images and movies showing C IV emission (transition
  region at 80,000 degrees) and UV continuum (temperature minimum
  region) of quiet and active regions. TRACE images using the 1550,
  1600, and 1700 Angstroms filters can be combined to estimate the total
  emission in the C IV 1548 and 1550 lines and the UV continuum. These
  are supplemented in different observations with MDI magnetograms, TRACE
  171 Angstroms images (Fe IX/X and perhaps O VI), and SUMER spectra of
  chromospheric and transition region lines from SOHO JOP 72. In quiet
  sun, bright C IV transients are seen in the vicinity of flux emergence,
  flux cancellation, and less dramatic interactions of small magnetic
  structures. Some of these are accompanied by high-velocity explosive
  events seen in SUMER spectra. The C IV emission can be well-separated
  from the photospheric magnetic footpoints, suggesting that it takes
  place on current sheets higher in the atmosphere separating different
  flux systems. In active regions, both bright and dark fibrils or loops
  are seen in C IV. Many nano/micro/sub flares are seen, some but not
  all of which are associated with emerging flux. The C IV emission of
  "moss" regions, footpoints of hot coronal loops, is contrasted with
  that of similar plage which does not have hot loops above it. This work
  was supported by the NASA contracts and grants for TRACE, MDI, and SOHO.

Title: The Solar-B Solar Optical Telescope Focal Plane Package
Authors: Levay, M.; Berger, T.; Rosenberg, W.; Tarbell, T.; Title,
   A.; Bogdan, T.; Elmore, D.; Lites, B.
Bibcode: 1999AAS...194.7610L
Altcode: 1999BAAS...31R.957L
  The primary goal of the Solar-B mission is to understand the physical
  processes responsible for dynamics and heating of the outer solar
  atmosphere. The Focal Plane Package (FPP) instrument for the 50-cm Solar
  Optical Telescope provides precise measurements of the vector magnetic
  field, vertical and horizontal flows, and thermal conditions in the
  photosphere and low chromosphere with spatial resolution as high as
  0.16 arcsec and a field-of-view as large as 320 x 160 arcsec. The FPP
  can measure continuously and at high cadence to follow the evolution
  of solar features. The FPP consists of broad ( 8 Angstroms) and narrow
  ( 100 m Angstroms) filters and a spectro-polarimeter that provides
  precise polarimetry with high spectral resolution ( 25 m Angstroms). A
  correlation tracker and tip-tilt mirror ensure that all focal planes
  are stable to better than 0.01 arcsec. A major design consideration
  of the FPP is cooperative science operations with the other Solar-B
  instruments. Solar-B is a Japanese mission with US and UK partners;
  S. Tsuneta is the PI of the Solar Optical Telescope and A. Title the
  US PI of the FPP. It is scheduled to launch in Japanese FY 2004.

Title: A new view of the solar corona from the transition region
    and coronal explorer (TRACE)
Authors: Golub, L.; Bookbinder, J.; Deluca, E.; Karovska, M.; Warren,
   H.; Schrijver, C. J.; Shine, R.; Tarbell, T.; Title, A.; Wolfson,
   J.; Handy, B.; Kankelborg, C.
Bibcode: 1999PhPl....6.2205G
Altcode:
  The TRACE Observatory is the first solar-observing satellite in the
  National Aeronautics and Space Administration's (NASA) Small Explorer
  series. Launched April 2, 1998, it is providing views of the solar
  transition region and low corona with unprecedented spatial and
  temporal resolution. The corona is now seen to be highly filamented,
  and filled with flows and other dynamic processes. Structure is seen
  down to the resolution limit of the instrument, while variability and
  motions are observed at all spatial locations in the solar atmosphere,
  and on very short time scales. Flares and shock waves are observed,
  and the formation of long-lived coronal structures, with consequent
  implications for coronal heating models, has been seen. This overview
  describes the instrument and presents some preliminary results from
  the first six months of operation.

Title: Observational Constraints on Models of the Solar Background
    Spectrum
Authors: Straus, Th.; Severino, G.; Deubner, F. -L.; Fleck, B.;
   Jefferies, S. M.; Tarbell, T.
Bibcode: 1999ApJ...516..939S
Altcode:
  We discuss the properties of the solar background signal as observed in
  high-quality, l-ν power and phase difference spectra of the continuum
  (C), velocity (V), and line intensity (I) fluctuations of the Ni
  I 6768 Å line. These spectra were generated from high-resolution
  images acquired by the Michelson Doppler Imager on board SOHO. <P />We
  confirm that the background signal in the velocity power spectra can be
  reproduced by a composite model with two quasi-stationary components,
  describing large-scale and small-scale convective motions, and a
  periodic component. The line and continuum intensity power spectra
  require additional quasi-stationary and periodic components. The
  extra quasi-stationary component dominates the intensity and
  continuum background signals over the spectral region where the I-V
  phase difference spectra show essentially constant negative phase
  difference: i.e., below and in between the p-mode ridges (called the
  plateau-interridge regime by Deubner et al.). Since the I-V phase
  between the p-mode ridges is not random, the solar background beneath
  the p-modes must be considered as coherent. We thus speculate that
  the negative phase regime may be the manifestation of a correlated
  background. Such a background has been proposed to explain the opposite
  sense of the asymmetries of the p-mode line profiles in velocity and
  brightness oscillations.

Title: Plasma Streaming and Explosive Events in the Solar Transition
Region: Theory and Observations
Authors: Ryutova, M.; Tarbell, T.
Bibcode: 1999AAS...194.7803R
Altcode: 1999BAAS...31..961R
  As shown by Tarbell et al. (ApJ, 514, L47, 1999 ) a sporadic excess of
  temperature and wide variety of plasma jets observed in the chromosphere
  and transition region overlying quiet sun regions may be explained by
  hydrodynamic cumulation resulted from the acoustic shocks generated by
  the reconnecting small scale network magnetic elements in the solar
  photosphere. Here we study magneto-hydrodynamic cumulation resulted
  from post-reconnection MHD shocks generated in complex magnetic field
  geometries typical to upper chromosphere and low corona. We present
  the results for the observed regularities obtained from simultaneous
  measurements taken by TRACE in chromospheric, transition region and
  coronal images and MDI on SOHO showing time series of high resolution
  magnetograms. We find that (1) All the essential features of the
  hydrodynamic cumulation remain in place: the MHD shocks driven by the
  post-reconnection sling-shot effect and self-focusing of these shocks
  lead to several well observed signatures of the energy release. (2) The
  evolution of generated flows depends on the geometry of intermittent
  magnetic fields and the height of jet formation. In regions of open
  magnetic structures plasma flows have tendency to accelerate and reach
  supersonic and super-Alfvenic velocities. Due to linear KH instability
  such flows may generate high frequency Alfven waves propagating along
  the magnetic structures. (3) In those regions where cumulative effects
  result in the predominant heating which is accompanied by generation of
  "moderate" (sub-Alfvenic) velocity jets, there are conditions when high
  velocity explosive events are driven. Our theoretical model shows that
  the explosive events proceeded by appearance of the bright transients
  are caused by the development of shear flow dissipative (nonlinear)
  instabilities. We also suggest that "non-bright"explosive events may
  be driven by rare effect of the cylindrical focusing of the MHD shocks
  (the Guderley's effect).

Title: Observations of Filaments
Authors: Title, A.; Schrijver, C.; Tarbell, T.; Shine, R.
Bibcode: 1999AAS...194.7905T
Altcode: 1999BAAS...31..963T
  Filaments are clearly seen as absorption features in the TRACE FE
  IX and XII images. Because of the 24 hour coverage of TRACE many
  filaments have been observed on the disk and near the limb, and as
  quiescent and active structures. A quiescent filament consists of many
  parallel strands the run nearly parallel to the surface. The strands
  are often at the TRACE resolution and are always in motion. Adjacent
  strands often exhibit flows in opposite directions with speeds of
  10 to 40 km/second. Filaments occasionally erupt explosive from the
  surface. The initial accelerations have not been observed with a 30
  second cadence. Velocities in the initial phase range between 200
  and 400 km/s. Filaments are observed to erupt and travel out of the
  TRACE field of view, erupt and fall back to the solar surface, and
  erupt and travel a short distance before being constraint by overlying
  fields. Examples of the dynamic structure of filaments and their modes
  of eruption will be demonstrated in a video presentation.

Title: Heating and Jet Formation by Hydrodynamic Cumulation in the
    Solar Atmosphere
Authors: Tarbell, T.; Ryutova, M.; Covington, J.; Fludra, A.
Bibcode: 1999ApJ...514L..47T
Altcode:
  The solar transition region is the site of supersonic plasma jets and
  sporadic radiative events, whose origin and physical nature have not
  been understood. Here we show that ubiquitous small-scale magnetic flux
  ``tubes,'' constantly emerging from subsurface layers, may cause the
  formation of plasma jets and a sporadic excess of temperature near
  the solar surface. These flux tubes collide and reconnect, creating
  a sling-shot effect that generates complex three-dimensional shock
  waves with the curved surface. Self-focusing of these shocks occurs
  as they propagate upward in the rarefied atmosphere. Depending on the
  geometry of the shock collision, highly concentrated energy may be
  converted entirely into either heat or strong jets, or distributed
  between the two.

Title: An eruption in the transition region observed with CDS and
    TRACE, on May 19, 1998.
Authors: Brekke, P.; Kjeldseth-Moe, O.; Tarbell, T.
Bibcode: 1999joso.proc..170B
Altcode:
  The authors present simultaneous CDS and TRACE observations in the EUV
  of an eruption of May 19, 1998. A large ejection of plasma was seen
  on the west limb and could be followed in EUV rasters in transition
  region lines with CDS and in high cadence images in the C<SUP>+3</SUP>
  155 nm line from TRACE. The onset of the eruption coincided with a
  weak flare observed with GOES. The eruption extended to 120000 km
  above the solar surface after 17 min and then fell back to the solar
  surface. At the leading edge of the eruption CDS observed Doppler
  shifts of 300 km s<SUP>-1</SUP> away from the observer (i.e. parallel
  to the solar surface) in the O<SUP>+4</SUP> line at 62.9 nm. High
  cadence observations with TRACE indicate that the plasma velocities
  perpendicular to the line of sight (i.e. along the solar vertical)
  reached similar values, i.e. 200 km s<SUP>-1</SUP>. Perhaps this was a
  "coronal mass ejection" that did not make it?

Title: Jets and Eruptions in the Transition Region Observed with CDS,
    EIT and TRACE
Authors: Brekke, P.; Kjeldseth-Moe, O.; Tarbell, T.; Gurman, J.
Bibcode: 1999ASPC..183..357B
Altcode: 1999hrsp.conf..357B
  No abstract at ADS

Title: The Transition Region and Coronal Explorer
Authors: Handy, B. N.; Deluca, E. E.; McMullen, R. A.; Schrijver,
   C. J.; Tarbell, T. D.; Title, A. M.; Wolfson, C. J.
Bibcode: 1998AAS...193.1207H
Altcode: 1998BAAS...30R1269H
  The Transition Region and Coronal Explorer (TRACE), launched 1 April
  1998, will have at the time of this meeting been in orbit for just over
  8 months. In that time, the instrument will have taken over 500,000
  exposures of the sun in ultraviolet and extreme ultraviolet wavelengths,
  will have completed three-forths of the nominal mission and will be
  approaching the end of the first eclipse season. The TRACE telescope
  is unique in its ability to observe in UV and EUV wavelengths at high
  cadence with unprecedented resolution. We present a review of the TRACE
  instrument and show current observations and results. We discuss the
  performance of the instrument in terms of observational capabilities,
  sensitivity, calibration, effects of aging on the instrument, CCD
  effects, and contamination effects.

Title: The TRACE Mission: Initial Scientific Results
Authors: Title, A. M.; Tarbell, T. D.; Wolfson, J.; Schrijver, K.;
   Fisher, R. R.; Gang, Th.; Golub, L.; McMullen, R. A.; Kankelborg,
   C.; TRACE Collaboration
Bibcode: 1998AAS...19310008T
Altcode: 1998BAAS...30R1398T
  TRACE (Transition Region and Coronal Explorer) is a Small Explorer
  Mission (SMEX) devoted to studying the evolution and propagation
  of fine-scale magnetic fields and plasma structures throughout the
  solar atmosphere. The instrument consists of a telescope with a 30 cm
  primary mirror, normal incidence coatings for three EUV bands (171,
  195 and 284 Angstroms), and interference filters for UV bands (1216
  to 1700 Angstroms) as well as white light (allowing the selection of
  temperature ranges from ~ 6 000 to ~ 2 500 000 degrees K). The 1024
  x 1024 CCD camera has a field of view of 8.5 arcmin with a spatial
  resolution of 1 arcsec and exposure times of 0.002 to 260 sec with
  a cadence as short as two seconds. The spacecraft was launched on
  April 1, 1998, and first light for the telescope occurred on April
  20. Observations have been collected nearly 24 hours per day since
  then, with no significant problems in any segment of the spacecraft,
  instrument, or mission operations. TRACE transmits about 3--4 GB of
  data per week which gets automatically reformatted and becomes available
  for the scientific community within approx. 24 hours. It is accessible
  without restrictions (only guidelines) together with other informations
  (technical details, educational material, movies, images,...) at:
  http://vestige.lmsal.com/TRACE. The images reveal activity in the
  solar atmosphere in stunning detail and include the first detailed
  observations of a magnetic energy release. This magnetic reconnection
  was observed on May 8, 1998, in a region of the solar atmosphere where
  two sets of perpendicular magnetic loops expanded into each other (see
  NASA Press Release 98-92). The TRACE mission has been developed and
  operated by NASA's Goddard Space Flight Center, Lockheed Martin Solar
  &amp; Astrophysics Laboratory, Smithsonian Astrophysical Observatory,
  and Montana State University.

Title: Spatiotemporal Correlations and Turbulent Photospheric Flows
    from SOHO/MDI Velocity Data
Authors: Cadavid, A. C.; Lawrence, J. K.; Ruzmaikin, A. A.; Walton,
   S. R.; Tarbell, T.
Bibcode: 1998ApJ...509..918C
Altcode:
  Time series of high-resolution and full-disk velocity images obtained
  with the Michelson Doppler Imager (MDI) instrument on board SOHO
  have been used to calculate the spacetime spectrum of photospheric
  velocity flow. The effects of different methods for filtering acoustic
  oscillations have been carefully studied. It is found that the spectra
  show contributions both from organized structures that have their origin
  in the convection zone and from the turbulent flow. By considering
  time series of different duration and cadence in solar regions with
  different line-of-sight projections, it is possible to distinguish the
  contributions of the spectra from the two different kinds of flows. The
  spectra associated with the turbulent velocity fields obey power laws
  characterized by two scaling parameters whose values can be used to
  describe the type of diffusion. The first parameter is the spectral
  exponent of the spatial correlation function and the second is a
  scaling parameter of the time correlation function. Inclusion of the
  time parameter is an essential difference between the present work
  and other solar studies. Within the confidence limits of the data,
  the values of the two parameters indicate that the turbulent part of
  the flow in the scale range 16-120 Mm produces superdiffusive transport.

Title: Efficiency loss of lumogen-coated CCDs by exposure to
    ultraviolet and extreme ultraviolet photons
Authors: Catura, Richard C.; Duncan, Dexter W.; Shing, Lawrence;
   Tarbell, Theodore D.; Wolfson, C. Jacob
Bibcode: 1998SPIE.3445..291C
Altcode:
  The efficiency of lumogen coated CCDs has been measured as a function of
  wavelength in the range from 171 angstrom to 1800 angstrom. A decrease
  in efficiency has been observe as a function of exposure of the lumogen
  to high levels of radiation at UV and extreme UV wavelengths. The drop
  in efficiency was found to be most rapid at lower exposure levels,
  decreasing in rate as the dosage increased.

Title: UV Observations with the Transition Region and Coronal Explorer
Authors: Handy, B. N.; Bruner, M. E.; Tarbell, T. D.; Title, A. M.;
   Wolfson, C. J.; Laforge, M. J.; Oliver, J. J.
Bibcode: 1998SoPh..183...29H
Altcode:
  The Transition Region and Coronal Explorer is a space-borne solar
  telescope featuring high spatial and temporal resolution. TRACE
  images emission from solar plasmas in three extreme-ultraviolet (EUV)
  wavelengths and several ultraviolet (UV) wavelengths, covering selected
  ion temperatures from 6000 K to 1 MK. The TRACE UV channel employs
  special optics to collect high-resolution solar images of the H i
  Lα line at 1216 Å, the C iv resonance doublet at 1548 and 1550 Å,
  the UV continuum near 1550 Å, and also a white-light image covering
  the spectrum from 2000-8000 Å.

Title: Helioseismic Studies of Differential Rotation in the Solar
    Envelope by the Solar Oscillations Investigation Using the Michelson
    Doppler Imager
Authors: Schou, J.; Antia, H. M.; Basu, S.; Bogart, R. S.; Bush,
   R. I.; Chitre, S. M.; Christensen-Dalsgaard, J.; Di Mauro, M. P.;
   Dziembowski, W. A.; Eff-Darwich, A.; Gough, D. O.; Haber, D. A.;
   Hoeksema, J. T.; Howe, R.; Korzennik, S. G.; Kosovichev, A. G.;
   Larsen, R. M.; Pijpers, F. P.; Scherrer, P. H.; Sekii, T.; Tarbell,
   T. D.; Title, A. M.; Thompson, M. J.; Toomre, J.
Bibcode: 1998ApJ...505..390S
Altcode:
  The splitting of the frequencies of the global resonant acoustic modes
  of the Sun by large-scale flows and rotation permits study of the
  variation of angular velocity Ω with both radius and latitude within
  the turbulent convection zone and the deeper radiative interior. The
  nearly uninterrupted Doppler imaging observations, provided by the
  Solar Oscillations Investigation (SOI) using the Michelson Doppler
  Imager (MDI) on the Solar and Heliospheric Observatory (SOHO) spacecraft
  positioned at the L<SUB>1</SUB> Lagrangian point in continuous sunlight,
  yield oscillation power spectra with very high signal-to-noise ratios
  that allow frequency splittings to be determined with exceptional
  accuracy. This paper reports on joint helioseismic analyses of
  solar rotation in the convection zone and in the outer part of the
  radiative core. Inversions have been obtained for a medium-l mode set
  (involving modes of angular degree l extending to about 250) obtained
  from the first 144 day interval of SOI-MDI observations in 1996. Drawing
  inferences about the solar internal rotation from the splitting data
  is a subtle process. By applying more than one inversion technique
  to the data, we get some indication of what are the more robust
  and less robust features of our inversion solutions. Here we have
  used seven different inversion methods. To test the reliability and
  sensitivity of these methods, we have performed a set of controlled
  experiments utilizing artificial data. This gives us some confidence
  in the inferences we can draw from the real solar data. The inversions
  of SOI-MDI data have confirmed that the decrease of Ω with latitude
  seen at the surface extends with little radial variation through much
  of the convection zone, at the base of which is an adjustment layer,
  called the tachocline, leading to nearly uniform rotation deeper
  in the radiative interior. A prominent rotational shearing layer in
  which Ω increases just below the surface is discernible at low to
  mid latitudes. Using the new data, we have also been able to study the
  solar rotation closer to the poles than has been achieved in previous
  investigations. The data have revealed that the angular velocity
  is distinctly lower at high latitudes than the values previously
  extrapolated from measurements at lower latitudes based on surface
  Doppler observations and helioseismology. Furthermore, we have found
  some evidence near latitudes of 75° of a submerged polar jet which
  is rotating more rapidly than its immediate surroundings. Superposed
  on the relatively smooth latitudinal variation in Ω are alternating
  zonal bands of slightly faster and slower rotation, each extending
  some 10° to 15° in latitude. These relatively weak banded flows
  have been followed by inversion to a depth of about 5% of the solar
  radius and appear to coincide with the evolving pattern of ``torsional
  oscillations'' reported from earlier surface Doppler studies.

Title: Oscillations of sunspot magnetic fields
Authors: Rueedi, I.; Solanki, S. K.; Stenflo, J. O.; Tarbell, T.;
   Scherrer, P. H.
Bibcode: 1998A&A...335L..97R
Altcode:
  We report on velocity and magnetic field oscillations observed
  in sunspots using the MDI instrument onboard SOHO. In addition to
  the well-known velocity oscillations, the data clearly show highly
  localised oscillations of the magnetogram signal in different parts
  of the sunspots. We show that only oscillations of the magnetic field
  vector can produce the observed magnetogram oscillations, and that the
  observed phase relations suggest an origin in terms of magnetoacoustic
  gravity waves.

Title: Large-scale coronal heating by the small-scale magnetic field
    of the Sun
Authors: Schrijver, C. J.; Title, A. M.; Harvey, K. L.; Sheeley,
   N. R.; Wang, Y. -M.; van den Oord, G. H. J.; Shine, R. A.; Tarbell,
   T. D.; Hurlburt, N. E.
Bibcode: 1998Natur.394..152S
Altcode:
  Magnetic fields play a crucial role in heating the outer atmospheres
  of the Sun and Sun-like stars, but the mechanisms by which magnetic
  energy in the photosphere is converted to thermal energy in the corona
  remain unclear. Observations show that magnetic fields emerge onto
  the solar surface as bipolar regions with a broad range of length
  scales. On large scales, the bipolar regions survive for months before
  dispersing diffusively. On the smaller scales, individual bipolar
  regions disappear within days but are continuously replenished by new
  small flux concentrations, resulting in a sustained state of mixed
  polarity. Here we determine the rate of emergence of these small
  bipolar regions and we argue that the frequent magnetic reconnections
  associated with these regions (an unavoidable consequence of continued
  flux replacement) will heat the solar atmosphere. The model that
  describes the details of these mixed-polarity regions is complementary
  to the traditional diffusion model for large-scale flux dispersal and
  a combination of the two should lead to a more complete understanding
  of the role of magnetic fields in stellar atmospheres.

Title: First Results from the TRACE Mission
Authors: Title, A.; Tarbell, T.; Schrijver, C.; Wolfson, J.; Shine,
   R.; Hurlburt, N.; Golub, L.; Deluca, E.; Bookbinder, J.; Handy, B.;
   Acton, L.; Harrison, R.; Delaboudinere, J. -P.
Bibcode: 1998AAS...192.1507T
Altcode: 1998BAAS...30..841T
  The TRACE spacecraft was launched on 1 April and all systems are
  functioning as designed. The initial outgassing period will conclude
  on 20 April and the science program will then begin. TRACE is a UV-EUV
  imager with one arc second spatial resolution and is capable of taking
  images with a cadence as high as two seconds. We will present images
  and image sequences. We hope to present initial comparisons of magnetic
  evolution and transition region and coronal brightenings.

Title: The Postflare Loops and the Nearby Active Chromosphere of
1992 June 26: Addendum
Authors: Malherbe, J. -M.; Tarbell, T.; Wiik, J. E.; Schmieder, B.;
   Frank, Z.; Shine, R. A.; van Driel-Gesztelyi, L.
Bibcode: 1998ApJ...495..502M
Altcode:
  Video segments are presented that were processed from a quantitative
  study of the dynamics of the evolution of Hα postflare loops developed
  after a large solar flare. The high spatial resolution of the Swedish
  Vacuum Solar Telescope (SVST) at La Palma provided a unique set of
  data for such an event.

Title: Helio-Atmospheric Links Explorer (HALE): A MIDEX Experiment
    for Exploring the Emergence of Magnetic Flux from Below the Solar
    Photosphere through the Corona
Authors: Scherrer, P. H.; Title, A. M.; Bush, R. I.; Duvall, T. L.,
   Jr.; Gurman, J. B.; Kosovichev, J. T.; Hoeksema, A. G.; Poland, A. I.;
   Tarbell, T. D.
Bibcode: 1998ESASP.417..285S
Altcode: 1998cesh.conf..285S
  No abstract at ADS

Title: The Stellar and Planetary Explorer (SPEX) Mission
Authors: Schou, J.; Scherrer, P. H.; Brown, T. M.; Frandsen, S.;
   Horner, S. D.; Korzennik, S. G.; Noyes, R. W.; Tarbell, T. D.; Title,
   A. M.; Walker, A. B. C., II; Weiss, W. W.; Bogart, R. S.; Bush, R. I.;
   Christensen-Dalsgaard, J.; Hoeksema, J. T.; Jones, A.; Kjeldsen, H.
Bibcode: 1998ESASP.418..401S
Altcode: 1998soho....6..401S
  The Stellar and Planetary Explorer (SPEX) is a mission designed
  to search for terrestrial sized planets around sun-like stars using
  precise photometry. The planets will be detected by searching for the
  decrease in brightness associated with transits of the planets in front
  of their parent stars. One of the secondary scientific objective of
  SPEX is to do asteroseismology on a number of sun-like stars. SPEX
  is designed as a secondary payload on a commercial communications
  satellite and will have a design life time of three years. We will
  provide an overview of the SPEX scientific objectives and design,
  with particular emphasis on the prospects for doing asteroseismology.

Title: Phase spectra seen from space
Authors: Straus, Th.; Deubner, F. -L.; Fleck, B.; Marmolino, C.;
   Severino, G.; Tarbell, T.
Bibcode: 1998IAUS..185..455S
Altcode:
  We discuss preliminary results of a study of the dynamics of the solar
  atmosphere including a first space based investigation of k-omega phase
  difference spectra between velocity and intensity perturbations. The
  data, including simultaneous line shift, line depth, and continuum
  intensity measurements at disk center, have been obtained from a MDI
  time series in its high resolution mode. Line depth and continuum
  intensity are used to calculate the line intensity which is the more
  frequently used parameter in phase difference studies. We compare the
  results to ground based observations.

Title: Calibration and Stability of MDI Velocities
Authors: Beck, J. G.; Scherrer, P. H.; Bush, R. I.; Tarbell, T. D.
Bibcode: 1998ESASP.418..105B
Altcode: 1998soho....6..105B
  No abstract at ADS

Title: A Modification to the Calibration of MDI Velocities
Authors: Evans, S.; Ulrich, R. K.; Scherrer, P. H.; Bush, R. I.;
   Tarbell, T. D.
Bibcode: 1998ESASP.418..157E
Altcode: 1998soho....6..157E
  The ability of the Michelson Doppler Imager instrument used by the
  Solar Oscillations Investigation (Scherrer, et al, 1995) to produce
  velocity measurements is affected by center-to-limb effects on the Ni
  6768 AA line profile. These effects are removed by special calibration
  observations known as detunes. Part of the detune procedure involves the
  modelling of center-to-limb line profile changes by fitting a Gaussian
  to the line profile and varying both the model profile's depth and
  FWHM as a function of center-to-limb angle. However, the functions
  used for modelling both line depth and FWHM differ from those derived
  from data from both the Mt. Wilson 150' Tower and the Fourier Transform
  Spectrometer at Kitt Peak. This variation can produce velocity errors
  of ~100 m/s. By modifying the line depth and FWHM functions to conform
  to those derived from the data, an improved velocity calibration can
  be achieved.

Title: K-ϖ Phase Spectra Obtained from Space
Authors: Straus, Th.; Fleck, B.; Severino, G.; Deubner, F. -L.;
   Marmolino, C.; Tarbell, T.
Bibcode: 1998ESASP.417..293S
Altcode: 1998cesh.conf..293S
  No abstract at ADS

Title: Rotation and Zonal Flows in the Solar Envelope from the
    SOHO/MDI Observations
Authors: Scherrer, P. H.; Schou, J.; Bogart, R. S.; Bush, R. I.;
   Hoeksema, J. T.; Kosovichev, A. G.; Antia, H. M.; Chitre, S. M.;
   Christensen-Dalsgaard, J.; Larsen, R. M.; Pijpers, F. P.; Eff-Darwich,
   A.; Korzennik, S. G.; Gough, D. O.; Sekii, T.; Howe, R.; Tarbell,
   T.; Title, A. M.; Thompson, M. J.; Toomre, J.
Bibcode: 1997AAS...191.7310S
Altcode: 1997BAAS...29.1322S
  We report on the latest inferences concerning solar differential
  rotation that have been drawn from the helioseismic data that are now
  available from the Solar Oscillations Investigation (SOI) using the
  Michelson Doppler Imager (MDI) on the Solar and Heliospheric Observatory
  (SOHO). That spacecraft is positioned in a halo orbit near the Sun-Earth
  Lagrangian point L_1, in order to obtain continuous Doppler-imaged
  observations of the sun with high spatial fidelity. Doppler velocity,
  intensity and magnetic field images are recorded, based on modulations
  of the 676.8 nm Ni I solar absorption line. The high spatial resolution
  of MDI thereby permits the study of many millions of global resonant
  modes of solar oscillation. Determination and subsequent inversion
  of the frequencies of these modes, including the degeneracy-splitting
  by the rotation of the sun, enables us to infer how the sun's angular
  velocity varies throughout much of the interior. The current MDI data
  are providing substantial refinements to the helioseismic deductions
  that can be made about differential rotation both within the convection
  zone and in its transition to the radiative interior. The shearing
  layer evident in the angular velocity Omega just below the solar
  surface is becoming better defined, as is the adjustment layer or
  tachocline near the base of the convection zone. The MDI data are also
  revealing a prominent decrease in Omega at high latitudes from the
  rotation rate expressed by a simple three-term expansion in latitude
  that was originally deduced from surface Doppler measurements. Further,
  there are indications that a submerged polar vortex involving somewhat
  faster Omega than its surroundings exists at about 75(deg) in latitudes.

Title: Photospheric flows as measured by SOI/MDI
Authors: Hurlburt, N.; Frank, Z.; Shine, R.; Tarbell, T.; Title, A.;
   Simon, G.
Bibcode: 1997ASSL..225..285H
Altcode: 1997scor.proc..285H
  On 2 February and 7 March 1996, MDI on the SOHO spacecraft ran several
  hours to provide high resolution continuum images to map the horizontal
  flows near the equator and pole by correlation tracking. Here we present
  preliminary results on the performance of the tracking technique
  in measuring the differential rotation profile. These preliminary
  results are compared with each other and with corresponding results
  of previous studies.

Title: 3-D Magnetic Field Configuration Late in a Large Two-Ribbon
    Flare
Authors: Moore, R. L.; Schmieder, B.; Hathaway, D. H.; Tarbell, T. D.
Bibcode: 1997SoPh..176..153M
Altcode:
  We present Hα and coronal X-ray images of the large two-ribbon flare
  of 25-26 June, 1992 during its long-lasting gradual decay phase. From
  these observations we deduce that the 3-D magnetic field configuration
  late in this flare was similar to that at and before the onset of
  such large eruptive bipolar flares: the sheared core field running
  under and out of the flare arcade was S-shaped, and at least one
  elbow of the S looped into the low corona. From previous observations
  of filament-eruption flares, we infer that such core-field coronal
  elbows, though rarely observed, are probably a common feature of the
  3-D magnetic field configuration late in large two-ribbon flares. The
  rare circumstance that apparently resulted in a coronal elbow of the
  core field being visible in Hα in our flare was the occurrence of a
  series of subflares low in the core field under the late-phase arcade
  of the large flare; these subflares probably produced flaring arches
  in the northern coronal elbow, thereby rendering this elbow visible
  in Hα. The observed late-phase 3-D field configuration presented
  here, together with the recent sheared-core bipolar magnetic field
  model of Antiochos, Dahlburg, and Klimchuk (1994) and recent Yohkoh
  SXT observations of the coronal magnetic field configuration at
  and before the onset of large eruptive bipolar flares, supports the
  seminal 3-D model for eruptive two-ribbon flares proposed by Hirayama
  (1974), with three modifications: (1) the preflare magnetic field is
  closed over the filament-holding core field; (2) the preflare core
  field has the shape of an S (or backward S) with coronal elbows; (3)
  a lower part of the core field does not erupt and open, but remains
  closed throughout flare, and can have prominent coronal elbows. In
  this picture, the rest of the core field, the upper part, does erupt
  and open along with the preflare arcade envelope field in which it
  rides; the flare arcade is formed by reconnection that begins in the
  middle of the core field at the start of the eruption and progresses
  from reconnecting closed core field early in the flare to reconnecting
  `opened' envelope field late in the flare.

Title: Post-Flare Loops of 26 June 1992 - IV. Formation and Expansion
    of Hot and Cool Loops
Authors: Van Driel-Gesztelyi, L.; Wiik, J. E.; Schmieder, B.; Tarbell,
   T.; Kitai, R.; Funakoshi, Y.; Anwar, B.
Bibcode: 1997SoPh..174..151V
Altcode:
  Observations of the post-flare loops after the X3.9 flare which occurred
  on 25 June, 1992 at 20:11 UT by the Yohkoh/SXT in X-rays, as well as
  in Hα obtained at 5 different observatories, have provided a unique,
  longest ever, set of data for a study of the relationship between the
  hot and cool post-flare loops as they evolve. At any given time, the
  altitude difference between the hot X-ray loops of 6-7× 10<SUP>6</SUP>
  K and the cool Hα loops of 1.5× 10<SUP>4</SUP> K is related to the
  expansion rate of the loop systems and their cooling time. Therefore,
  measurements of the expansion rate and relative height of hot and
  cool loops can provide direct observational values for their cooling
  times. We measured the altitude of hot and cool loops for 15 and 19
  hours, respectively, and found that the cooling time increased as the
  density of the loops decreased. We found a reasonably good agreement
  between the observed cooling times and those obtained from model
  calculations, although the observed values were always somewhat longer
  than the theoretical ones. Taking into account evolutionary effects,
  we also found similar shapes and configurations of hot and cool loops
  during the entire observing period and confirmed that, at any time,
  hot loops are at higher altitude than cool loops, suggesting that cool
  loops indeed evolve from hot loops. These results were used to check
  the validity of the reconnection model.

Title: Properties of the Smallest Solar Magnetic
    Elements. II. Observations versus Hot Wall Models of Faculae
Authors: Topka, K. P.; Tarbell, T. D.; Title, A. M.
Bibcode: 1997ApJ...484..479T
Altcode:
  Observations obtained at the Swedish Solar Observatory, La Palma,
  using the Lockheed tunable filter, have been used to measure
  properties of active region faculae, including contrast from disk
  center to near the limb. The data consist of coregistered digital
  photometric images of the line-of-sight magnetic field and of the
  continuum intensity. <P />The results are related to the structure
  of the individual flux tubes comprising faculae in active regions. In
  addition to center-limb contrast, the observations reveal a change in
  contrast between heliocentric angles of about 45° and 60° related
  to the ``turn-on'' of bright faculae. A class of models has been
  constructed that describes a facula as an evacuated thin flux tube
  with a hot wall and a depressed cool floor (hot wall model). The
  hot wall model is very successful in predicting the observations,
  including the changes observed between 45° and 60°. <P />The model
  predicts that the larger flux tubes comprising active region plage are
  micropores with a Wilson depression of 100 km largely independent of
  micropore diameter. Their typical diameter is 350-650 km; the largest
  ones are about 1200 km across. Bright points are the major component of
  active region plages by number, but micropores probably are the major
  component by total magnetic flux. Bright active region faculae seen
  near the limb are simply micropores viewed from the side, where the hot
  wall is visible and the depressed cool floor is not. The temperature
  difference between cool floor and hot wall varies from 300 to nearly
  500 K, depending on tube diameter and heliocentric angle. <P />These
  results have important implications for solar irradiance variations.

Title: The Postflare Loops and the Nearby Active Chromosphere of
    1992 June 26
Authors: Malherbe, J. -M.; Tarbell, T.; Wiik, J. E.; Schmieder, B.;
   Frank, Z.; Shine, R. A.; van Driel-Gesztelyi, L.
Bibcode: 1997ApJ...482..535M
Altcode:
  The main objective of this paper is to present a quantitative study
  of the dynamics of the evolution of Hα postflare loops developed
  after a large solar flare and the processed videos produced from the
  observations. The high spatial resolution of the Swedish Vacuum Solar
  Telescope (SVST) at La Palma has provided a unique set of data for such
  an event. A Gaussian fitting method is proposed to derive intensities
  and Doppler shifts from observations taken at three wavelengths (Hα
  center and Hα +/- 0.07 nm). Moving condensations or ``blobs'' of cold
  material provide transverse velocities, which, together with the radial
  component, enable us to derive their velocity vector magnitude. Plasma
  velocities are around free-fall velocities near the top of the loops
  but are significantly smaller close to their footpoints, suggesting
  a deceleration mechanism. The loops are anchored in the chromosphere,
  which shows tremendous activity in the active region and in the nearby
  ``quiet Sun.'' Spicules and ejection of plasmoids are also observed
  at the limb.

Title: On the Dynamics of Magnetic Flux Concentrations in Quiet
    Photospheric Network.
Authors: Sakai, J. I.; Ryutova, M.; Schrijver, K.; Shine, R.; Tarbell,
   T.; Berger, T.; Title, A.; Hagenaar, H.
Bibcode: 1997SPD....28.0260S
Altcode: 1997BAAS...29..904S
  Magnetic flux concentrations in the quiet photospheric network show
  a complex dynamics which includes merging of colliding fluxes, the
  "total" or partial cancellation of neighboring fluxes, fragmentation
  and others. We propose a mechanism to explain the observed phenomena
  based on the idea that magnetic flux concentrations in the photospheric
  network are essentially non-collinear. We show that non-collinearity
  of colliding fluxes leads to the whole new class of effects which are
  observed; for example, the apparent cancellation of opposite polarity
  fluxes turns into the formation of horizontal magnetic fluxes (which
  later may appear as a new weaker bipoles) and is accompanied by the
  shock formation and mini-flares. In the case of shock formation
  the reconnection area becomes a source of the acoustic emission;
  mini-flares may be seen as bright points. The energetics of these
  processes strongly depends on geometry of "collision" and physical
  parameters of colliding fluxes. For example, if colliding fluxes have
  comparable and "small" cross sections, the reconnection results in
  complete reorganization of their magnetic fields; if merging fluxes
  are large enough or considerably different, magnetic flux may be
  only partially reconnected and partially survived. Reconnection of
  non-collinear equal polarity fluxes leads to the "scattering" processes
  which include the fragmentation into several smaller fluxes if initially
  colliding concentrations carried different amount of magnetic flux. We
  give the example of numerical simulation for the case of merging and
  fragmentation process occurring during the collision of collinear
  "strong" and "weak" magnetic flux concentrations. The calculation
  results shown to be consistent with observational data from both
  the SOHO/MDI instrument and the Swedish Vacuum Solar Telescope on
  La Palma. This research is supported by NASA contract NAG5-3077 at
  Stanford University and the MDI contract PR 9162 at Lockheed.

Title: Photospheric Differential Rotation from Full-Disk SOI/MDI
    Dopplergrams
Authors: Bogart, R. S.; Bai, T.; Scherrer, P. H.; Strous, L. H.;
   Simon, G. W.; Tarbell, T. D.
Bibcode: 1997SPD....28.0258B
Altcode: 1997BAAS...29..903B
  We report on measurements of the solar surface differential rotation
  made from SOI/MDI full-disk Dopplergrams obtained once per minute during
  the 2-month Dynamics Program from 23 May through 26 July 1996. We infer
  the rotation profile both from the direct photospheric Doppler signal
  and also by tracking Doppler features (supergranules) across the solar
  disk. We study the rotation curve as a function of latitude, feature
  size, and tracking method, and look for global scale flows. This work
  was supported by NASA Grant NAG5-3077 at Stanford and Lockheed Martin,
  and by AFOSR and the Fellows Program of AF Phillips Lab at NSO/SP.

Title: Comparison of Granulation Correlation Tracking (CT) and
    Feature Tracking (FT) Results from SOHO/MDI and the Swedish Vacuum
    Solar Telescope on La Palma
Authors: Shine, R.; Strous, L.; Simon, G.; Berger, T.; Hurlburt, N.;
   Tarbell, T.; Title, A.; Scharmer, G.
Bibcode: 1997SPD....28.0262S
Altcode: 1997BAAS...29Q.904S
  We have computed photospheric velocity flow maps from simultaneous
  observations taken with MDI and at the Swedish Vacuum Solar Tower
  (SVST) on La Palma on August 15, 1996. Both sets consist of a series
  of photospheric images, and flow maps are computed by following the
  local motions of granules. The MDI data have the important advantages
  of very stable images and longer continuous coverage of the same area
  of the solar surface. This longer coverage is necessary to study the
  evolution of mesogranules, supergranules, and to detect possible low
  amplitude motions on scales larger than supergranules. However, the
  high resolution mode of MDI is limited by the small telescope size to
  about 1.2 arc seconds angular resolution and uses a 0.6 arc second pixel
  size. This is adequate to show granulation but has the rms constrast
  significantly reduced to about 2%. Early efforts adapting techniques
  that were successful with higher resolution ground based images gave
  poor results and although new methods have now been developed, there
  are still some problems with accuracy. On the other hand, the SVST
  images have much higher angular resolution (as good as 0.2 arc second)
  but suffer from variable atmospheric distortion. They also have a much
  smaller field of view. By detailed comparison of the two data sets
  and by using CT and FT techniques to track the motions, we hope to
  understand the sources of any differences between them and to develop
  credible correction parameters to the MDI data sets if necessary. This
  work was supported by NASA Grant NAG5-3077 at Stanford and Lockheed
  Martin, by AFOSR and the Fellows Program of AF Phillips Lab at NSO/SP,
  and by the Swedish Royal Academy of Sciences.

Title: Initial Comparison of MDI Photospheric Magnetic Movies and
    CDS Transition Region Movies in Quiet Sun
Authors: Tarbell, T.; Brekke, P.; Fludra, A.; Deforest, C.; Saba,
   J.; Covington, J.
Bibcode: 1997SPD....28.0111T
Altcode: 1997BAAS...29..881T
  We present simultaneous, coaligned movies of photospheric magnetic
  fields and transition region (TR) intensities in very quiet sun near
  disk center obtained by SOHO in January, 1997. For example, the 22 Jan
  1997 CDS movies show He I 584 (2x10(4) K) and O V 630 (2.4 x 10(5) K)
  from 16:51 to 19:54 UT, with a 310 x 240 arcsecond field of view, 105
  second cadence, and 1.7 arcsecond pixels. MDI photospheric longitudinal
  magnetograms, with 60 second cadence and 0.6 arcsecond pixels, have been
  coaligned with these. Bright TR emission correlates more strongly with
  close bipoles in the photospheric magnetic field than with magnetic
  flux alone. Some strong photospheric flux tubes are barely visible
  in the TR emission, appearing only occasionally in connections with
  nearby weak opposite polarity fields. Bright transient emissions in
  the TR are located at places of cancelling opposite polarities in
  photospheric magnetic fields. The flux cancellation continues for tens
  of minutes or hours in the magnetic movies. Searches for more rapid
  magnetic counterparts to these TR transients and for emerging magnetic
  flux regions in the movies are under way. This work was supported by
  NASA grant NAG5-3077 at Stanford and Lockheed Martin.

Title: Surface Flows in Active Regions
Authors: Bai, T.; Bogart, R. S.; Scherrer, P. H.; Tarbell, T. D.
Bibcode: 1997SPD....28.1701B
Altcode: 1997BAAS...29..921B
  Plasma flows around sunspots must influence the stability and
  development of sunspots. We have been studying photospheric flows
  around sunspots by analyzing dopplergrams and magneto- grams obtained
  by the MDI (Michelson Doppler Imager) aboard SOHO. We have found some
  interesting phenomena. First, during the growing phase of an active
  region, plasmas around sunspots seem to draft downward with a speed of
  order of 100 m/s. Second, during the decaying phase of an active region,
  plasmas around sunspots flow outward. Outflow speeds range up to several
  hundred m/s. Such outflows are prominent during the decaying phase of
  a long-lived big active region. Third, there is evidence for flows
  within sunspots. Such flows are presumed to be along magnetic field
  lines. We will present the details of these results and discuss their
  implications on the dynamics and stability of sunspots. MDI research
  is supported by NASA contract NAG5-3077 at Stanford University.

Title: Solar Irradiance Variations due to the Quiet Sun Network
Authors: Topka, K. P.; Tarbell, T. D.; Title, A. M.
Bibcode: 1997SPD....28.0263T
Altcode: 1997BAAS...29..904T
  An estimate for the change in total solar irradiance due to quiet sun
  network during the 11-year solar cycle is presented. The estimate is
  based on measurements of the center-limb contrast function for quiet
  sun magnetic elements. These measurements are the result of analysis
  of near-simultaneous, co-registered, digital, photometric images of
  the photospheric intensity (4300 - 6300 A) and line-of-sight magnetic
  field. Images were made with the Lockheed tunable filter instrument at
  the Swedish Solar Observatory, La Palma, between 1991 and 1994. The
  result is of order 0.1%. The images cover only a tiny fraction of
  the surface of the Sun and thus a very large extrapolation is made,
  limiting the accuracy of the result. Measurements made by satellite
  radiometers indicate that on the time scale of solar activity, the total
  solar irradiance is greater at activity maximum than at minimum by about
  0.1 to 0.15 %. Our result is consistent with this. Earlier results on
  active region plage, using similar data from La Palma, indicate that it
  does does not contribute significantly to long-term solar irradiance
  variations. This work has been supported by NSF contract ATM-9320353,
  by NASA contracts NASW-4612 and NAS8-39747, and by Lockheed IR funds.

Title: The Height and Temporal Structure of X-Ray Bright Points
Authors: Harvey, K. L.; Penn, M.; Tarbell, T.; Saba, J.; Hassler,
   D.; Moses, J. D.; Fludra, A.
Bibcode: 1997SPD....28.0124H
Altcode: 1997BAAS...29..883H
  On April 12, 1996, several ground-based observatories, the Yohkoh/SXT
  and the SOHO/MDI, EIT, SUMER, and CDS instruments participated in a
  collaborative study of X-Ray Bright Points (XBPs). During a several
  hour period, simultaneous images were obtained of an area centered
  at N10E00. At NSO/KP, observations were made of the HeI 1083 nm line
  profile from which we have derived the intensity at line center,
  equivalent width, and the velocity at every 1 pixel (1.15 arc-seconds)
  within an 8 x 8 arc-minute area. Our paper will present the results
  of a comparison, spatially and temporally, of these data with changes
  in the magnetic field observed by the MDI, intensities and velocities
  observed with SUMER and CDS, and the intensity images observed by
  the SXT and EIT. We will use this ensemble of intensity, magnetic
  and velocity field images to derive the height structure of XBPS,
  its variation as a function of time and relation to the associated
  magnetic field configuration.

Title: A search for interaction between magnetic fields and
    supergranular flows in the network based on MDI observations
Authors: Schrijver, C. J.; Shine, R. A.; Title, A. M.; Hagenaar,
   H. J.; Hurlburt, N. E.; Tarbell, T. D.; Simon, G. W.
Bibcode: 1997SPD....28.0243S
Altcode: 1997BAAS...29..901S
  We study the supergranular flow field and its temporal evolution in
  the quiet Sun as observed with the Michelson Doppler Imager on board
  SOHO. We use the intensity images to derive the flow fields using
  local correlation tracking. The data sets span one to two days with a
  one--minute cadence. We separate areas with a relatively high filling
  factor for magnetic concentrations from areas with a low magnetic
  filling factor in order to study to what extent the flows influence
  the magnetic network in the quiet Sun and vice versa. This work is
  supported by NASA Grant NAG5-3077 at Stanford and Lockheed Martin,
  and by AFOSR and the Fellows Program of AF Phillips Lab at NSO/SP

Title: Continuous Observations of Solar Magnetic Fields from SOI/MDI
    on SOHO
Authors: Hoeksema, J. T.; Bush, R. I.; Scherrer, P. H.; Heck, C.;
   Hurlburt, N.; Shine, R.; Tarbell, T.; Title, A.
Bibcode: 1997SPD....28.0127H
Altcode: 1997BAAS...29..884H
  The Solar Oscillations Investigation's Michelson Doppler Imager
  instrument (SOI/MDI) on SOHO measures the photospheric magnetic field
  over the whole disk nearly every 96 minutes with 4" resolution and a
  noise level of a few Gauss. Beginning in April 1996, this unprecedented
  continuous series of frequent, uniform quality magnetograms provides
  a striking view of the continual emergence, motion, evolution, and
  interaction of magnetic flux everywhere on the visible solar surface
  near solar minimum. These evolving photospheric fields ultimately
  drive the variations of the corona and solar wind that affect the
  terrestrial environment. Knowledge of the rapidly evolving photospheric
  field provides a crucial input for forecasting conditions in the
  corona, heliosphere, and geospace. A few magnetograms are available
  each day within hours of observation through the SOHO web site at
  http://sohowww.nascom.nasa.gov/. These may be used for planning and
  forecasting, e.g. to compute models of the solar corona. The remainder
  are generally available within a few weeks. Sometimes more focused
  campaigns provide magnetic observations as often as once each minute
  for up to 8 hours. Campaigns can be run with either the full disk
  resolution or with 0.6" pixels in a limited field near the center of
  the disk. The SOI project welcomes collaborations. More information
  can be found at http://soi.stanford.edu/.

Title: The TRACE Mission
Authors: Wolfson, J.; Bruner, M.; Jurcevich, B.; Lemen, J.; Schrijver,
   K.; Shine, R.; Strong, K.; Tarbell, T.; Title, A.; Golub, L.;
   Bookbinder, J.; Deluca, E.; Acton, L.; Handy, B.; Kankelborg, C.;
   Fisher, R.
Bibcode: 1997SPD....28.0143W
Altcode: 1997BAAS...29..887W
  The TRACE (Transition Region and Coronal Explorer) mission will explore
  the connections between fine-scale magnetic fields and plasma structures
  in the coronal, transition zone and temperature minimum regions of the
  sun. TRACE will collect images of solar plasmas at temperatures from
  10(4) to 10(7) K, with one arc second spatial resolution and excellent
  temporal resolution and continuity. With a scheduled launch date of 15
  December 1997, the mission will emphasize collaborative observations
  with SoHO, enabling simultaneous observations of high-resolution images,
  spectra, and magnetograms. The 30 cm aperture TRACE telescope uses four
  normal-incidence coatings for the EUV and UV on quadrants of the primary
  and secondary mirrors. Interference filters further isolate 5 different
  UV bands. The images are co-aligned and internally stabilized against
  spacecraft jitter. A 1024 x 1024 lumigen-coated CCD detector collects
  images over an 8.5 x 8.5 arc minute field-of-view. LMATC, SAO, and GSFC
  built the TRACE instrument, which was integrated with the GSFC-produced
  SMEX spacecraft on 28 February (just over two years from the start
  of its development). It will be put into a Sun-synchronous orbit and
  operated in coordination with the SoHO Experiment Operations Facility at
  GSFC. We are committed to maintaining a publicly accessible data base
  for TRACE data. Browsing and data set requesting capabilities will be
  provided at Web site www.space.lockheed.com/TRACE/TRACElinks.html. This
  site already contains a large volume of information on the mission
  including preliminary scientific observing programs and directions
  as to how to participate in the mission now and in the future. This
  project is supported by NASA contract NAS5-38099.

Title: Performance of the Michelson Doppler Imager Instrument on SOHO
Authors: Scherrer, P.; Bogart, R.; Bush, R.; Duvall, T.; Hoeksema,
   J. T.; Kosovichev, A.; Schou, J.; Morrison, M.; Tarbell, T.; Title, A.
Bibcode: 1997SPD....28.0207S
Altcode: 1997BAAS...29..894S
  Launched on SOHO in December 1995, the MDI instrument took its 10
  millionth filtergram in early April, 1997. The instrument and spacecraft
  have performed admirably since commissioning, providing over a year
  of virtually uninterrupted time series of velocity and intensity
  measurements at moderate resolution, a continuous 60-day time series
  of full disk 4" velocity and line depth maps, monthly 72+ hour time
  series in various observables, a host of daily 8-hour campaigns, and
  full-disk magnetograms every 96 minutes. Another uninterrupted 90-day
  interval of nearly full data recovery is scheduled to be completed in
  mid July. Various scientific results using MDI data are being presented
  at this meeting. About a dozen terabytes of data sets have been created
  and archived and normal pipeline processing is now completed soon after
  retrieving the data, typically less than a month after the observations
  are made. Most of the data products are generally available on the WWW,
  see http://soi.stanford.edu. Selected data are available in near real
  time. The SOI team welcomes collaborations. Routine and extraordinary
  calibrations along with analysis of scientific data sets allow us to
  make good estimates of the noise and understand many of the sources
  of systematic errors in the instrument. In almost every respect the
  instrument performs as well or better than expected before launch,
  the primary limitations being photon noise on the short term and
  fixed or slowly varying offsets on the long term. We have found that
  the Michelsons are somewhat more sensitive to operational temperature
  variations than was expected, adding some additional constraints on
  our observing sequences.

Title: 3-D Magnetic Field Configuration Late in a Large Two-Ribbon
    Flare
Authors: Moore, R. L.; Schmieder, B.; Hathaway, D. H.; Tarbell, T. D.
Bibcode: 1997SPD....28.0157M
Altcode: 1997BAAS...29R.889M
  We present H-alpha and coronal X-ray images of the large two-ribbon
  flare of 25/26 June 1992 during its long-lasting gradual decay
  phase. From these observations we deduce that the 3-D magnetic field
  configuration late in this flare was similar to that at and before the
  onset of such large eruptive bipolar flares: the sheared core field
  running under and out of the flare arcade was S-shaped, and at least one
  elbow of the S looped into the low corona. From previous observations
  of filament-eruption flares, we infer that such core-field coronal
  elbows, though rarely observed, are probably a common feature of the
  3-D magnetic field configuration late in large two-ribbon flares. The
  rare circumstance that apparently resulted in a coronal elbow of the
  core field being visible in H-alpha in our flare was the occurrence
  of a series of subflares low in the core field under the late-phase
  arcade of the large flare; these subflares probably produced flaring
  arches in the northern coronal elbow, thereby rendering this elbow
  visible in H-alpha. The observed late-phase 3-D field configuration
  presented here, together with the recent sheared-core bipolar magnetic
  field model of Antiochos, Dahlburg, and Klimchuk (1994) and recent
  Yohkoh SXT observations of the coronal magnetic field configuration
  at and before the onset of large eruptive bipolar flares, supports the
  seminal 3-D model for eruptive two-ribbon flares proposed by Hirayama
  (1974), with three modifications: (1) the preflare magnetic field is
  closed over the filament-holding core field; (2) the preflare core
  field has the shape of an S (or backward S) with coronal elbows; (3)
  a lower part of the core field does not erupt and open, but remains
  closed throughout flare, and can have prominent coronal elbows. In
  this picture, the rest of the core field, the upper part, does erupt
  and open along with the preflare arcade envelope field in which it
  rides; the flare arcade is formed by reconnection that begins in the
  middle of the core field at the start of the eruption and progresses
  from reconnecting closed core field early in the flare to reconnecting
  "opened" envelope field late in the flare.

Title: Comparison of supergranular flows from doppler and local
    correlation tracking velocities
Authors: Frank, Z.; Hurlburt, N.; Shine, R.; Tarbell, T.; Simon, G.;
   Strous, L.; Matt, S.
Bibcode: 1997SPD....28.0259F
Altcode: 1997BAAS...29..903F
  Measurements of the flows in the solar photosphere rely upon two
  techniques: doppler measurements of the line-of-sight velocity
  or tracking of features or patterns moving perpendicular to the
  line-of-sight. These methods have differing characteristics. Doppler
  measurements can easily measure surface flows near the limb
  which are not seriously contaminated by p-modes or other solar
  sources. However, they require excellent instrument calibration over
  the full field of view. Even then vertical flows within supergranules
  are barely detectable. Correlation and feature tracking have proven
  useful for estimating transverse velocity using granules and other
  tracers. Nevertheless, they can be degraded by the intensity variations
  of p-modes and possibly other oscillatory motions, as well as by effects
  of limb darkening and foreshortening. The two methods would both be
  strengthened through detailed comparisons. Data collected by MDI/SOHO is
  ideal for this purpose. The data is co-spatial and co-temporal, and is
  all obtained through the same instrument. We compare Doppler velocities
  with those obtained through correlation tracking using high-resolution
  MDI/SOHO images. We focus on motions at positions exceeding 30 degrees
  from disk center. After taking projection effects into account, we
  combine the two measurements to form a three-dimensional picture of
  the flows in the average supergranule. This work was supported by NASA
  Grant NAG5-3077 at Stanford and Lockheed Martin, and by AFOSR and the
  Fellows Program of AF Phillips Lab at NSO/SP.

Title: Interactive interface for visualizing and analyzing
    multispectral solar images
Authors: Hurlbert, Neal E.; Shine, Richard A.; Tarbell, Theodore D.
Bibcode: 1997SPIE.3017..165H
Altcode:
  We present an interactive software tool for manipulating image data,
  especially high resolution multi-spectral solar movies and images
  from several different instruments. This tool contains procedures for
  distortion removal for ground based solar movies, correlation tracking,
  image alignments, data compression, 3D FOurier filtering, interactive
  viewing of space/time slices in movies, and browsing through data
  cubes. This is a compete public domain package based on X windows
  and Unix which is currently running on Silicon Graphics and Digital
  Equipment workstations. These software tools are freely available to
  the international solar community. Many components are also applicable
  to image an movie analysis in astrophysics, space physics, and earth
  sciences. They are available with documentation via our web pages
  under http://www.space.lockheed.com.

Title: Structure and Rotation of the Solar Interior: Initial Results
    from the MDI Medium-L Program
Authors: Kosovichev, A. G.; Schou, J.; Scherrer, P. H.; Bogart, R. S.;
   Bush, R. I.; Hoeksema, J. T.; Aloise, J.; Bacon, L.; Burnette, A.; de
   Forest, C.; Giles, P. M.; Leibrand, K.; Nigam, R.; Rubin, M.; Scott,
   K.; Williams, S. D.; Basu, Sarbani; Christensen-Dalsgaard, J.; Dappen,
   W.; Rhodes, E. J., Jr.; Duvall, T. L., Jr.; Howe, R.; Thompson, M. J.;
   Gough, D. O.; Sekii, T.; Toomre, J.; Tarbell, T. D.; Title, A. M.;
   Mathur, D.; Morrison, M.; Saba, J. L. R.; Wolfson, C. J.; Zayer, I.;
   Milford, P. N.
Bibcode: 1997SoPh..170...43K
Altcode:
  The medium-l program of the Michelson Doppler Imager instrument on board
  SOHO provides continuous observations of oscillation modes of angular
  degree, l, from 0 to ∽ 300. The data for the program are partly
  processed on board because only about 3% of MDI observations can be
  transmitted continuously to the ground. The on-board data processing,
  the main component of which is Gaussian-weighted binning, has been
  optimized to reduce the negative influence of spatial aliasing of the
  high-degree oscillation modes. The data processing is completed in a
  data analysis pipeline at the SOI Stanford Support Center to determine
  the mean multiplet frequencies and splitting coefficients. The initial
  results show that the noise in the medium-l oscillation power spectrum
  is substantially lower than in ground-based measurements. This enables
  us to detect lower amplitude modes and, thus, to extend the range of
  measured mode frequencies. This is important for inferring the Sun's
  internal structure and rotation. The MDI observations also reveal the
  asymmetry of oscillation spectral lines. The line asymmetries agree
  with the theory of mode excitation by acoustic sources localized in the
  upper convective boundary layer. The sound-speed profile inferred from
  the mean frequencies gives evidence for a sharp variation at the edge
  of the energy-generating core. The results also confirm the previous
  finding by the GONG (Gough et al., 1996) that, in a thin layer just
  beneath the convection zone, helium appears to be less abundant than
  predicted by theory. Inverting the multiplet frequency splittings from
  MDI, we detect significant rotational shear in this thin layer. This
  layer is likely to be the place where the solar dynamo operates. In
  order to understand how the Sun works, it is extremely important to
  observe the evolution of this transition layer throughout the 11-year
  activity cycle.

Title: On the dynamics of magnetic flux concentrations in quiet
    photospheric network.
Authors: Sakai, J. I.; Ryutova, M.; Schrijver, K.; Shine, R. A.;
   Tarbell, T. D.; Berger, T. E.; Title, A. M.; Hagenaar, H. J.
Bibcode: 1997BAAS...29T.904S
Altcode:
  No abstract at ADS

Title: The Dynamic Quiet Solar Corona: 4 Days of Joint Observing
    with MDI and EIT
Authors: Schrijver, C. J.; Shine, R. A.; Hurlburt, N. E.; Tarbell,
   T. D.; Lemen, J. R.
Bibcode: 1997ESASP.404..669S
Altcode: 1997cswn.conf..669S
  No abstract at ADS

Title: Internal structure and rotation of the Sun: First results
    from MDI data
Authors: Kosovichev, A. G.; Schou, J.; Scherrer, P. H.; Bogart, R. S.;
   Bush, R. I.; Hoeksema, J. T.; Aloise, J.; Bacon, L.; Burnette, A.;
   De Forest, C.; Giles, P. M.; Leibrand, K.; Nigam, R.; Rubin, M.;
   Scott, K.; Williams, S. D.; Basu, Sarbani; Christensen-Dalsgaard,
   J.; Däppen, W.; Rhodes, E. J., Jr.; Duvall, T. L., Jr.; Howe, R.;
   Thompson, M. J.; Gough, D. O.; Sekii, T.; Toomre, J.; Tarbell, T. D.;
   Title, A. M.; Mathur, D.; Morrison, M.; Saba, J. L. R.; Wolfson,
   C. J.; Zayer, I.; Milford, P. N.
Bibcode: 1997IAUS..181..203K
Altcode:
  No abstract at ADS

Title: Temporal Variability in the Quiet Sun Transition Region
Authors: Wikstoøl, Ø.; Hansteen, V. H.; Brynildsen, N.; Maltby,
   P.; Kyeldseth-Moe, O.; Harrison, R. A.; Wilhelm, K.; Tarbell, T. D.;
   Scherrer, P. H.
Bibcode: 1997ESASP.404..733W
Altcode: 1997cswn.conf..733W
  No abstract at ADS

Title: Time-Distance Helioseismology with the MDI Instrument:
    Initial Results
Authors: Duvall, T. L., Jr.; Kosovichev, A. G.; Scherrer, P. H.;
   Bogart, R. S.; Bush, R. I.; de Forest, C.; Hoeksema, J. T.; Schou,
   J.; Saba, J. L. R.; Tarbell, T. D.; Title, A. M.; Wolfson, C. J.;
   Milford, P. N.
Bibcode: 1997SoPh..170...63D
Altcode:
  In time-distance helioseismology, the travel time of acoustic waves
  is measured between various points on the solar surface. To some
  approximation, the waves can be considered to follow ray paths that
  depend only on a mean solar model, with the curvature of the ray
  paths being caused by the increasing sound speed with depth below the
  surface. The travel time is affected by various inhomogeneities along
  the ray path, including flows, temperature inhomogeneities, and magnetic
  fields. By measuring a large number of times between different locations
  and using an inversion method, it is possible to construct 3-dimensional
  maps of the subsurface inhomogeneities. The SOI/MDI experiment on SOHO
  has several unique capabilities for time-distance helioseismology. The
  great stability of the images observed without benefit of an intervening
  atmosphere is quite striking. It has made it possible for us to detect
  the travel time for separations of points as small as 2.4 Mm in the
  high-resolution mode of MDI (0.6 arc sec pixel<SUP>-1</SUP>). This has
  enabled the detection of the supergranulation flow. Coupled with the
  inversion technique, we can now study the 3-dimensional evolution of
  the flows near the solar surface.

Title: On the Acoustic Emission in the Quiet Sun
Authors: Ryutova, M. P.; Tarbell, T. D.
Bibcode: 1997AAS...18912001R
Altcode: 1997BAAS...29..729R
  The interaction of solar acoustic oscillations with magnetic regions on
  the Sun strongly depends on the distribution of the random magnetic
  fluxes in space and their physical parameters. The dynamics of
  differently magnetized regions (sunspots, plages and quiet Sun), their
  dispersion properties and their response to the propagation of acoustic
  waves are completely different. For example, the enhanced absorption of
  acoustic power by sunspot and plage regions is well established. Several
  authors who have made similar measurements in quiet regions report that
  the quiet Sun shows small but systematic acoustic emission. The effects,
  enhanced absorption in active regions and "emission' of acoustic power
  in quiet sun, are seen in the same range of wave numbers (0.2&lt;=
  k &lt;= 0.6 Mm(-1) ). We report here that an excess of emission of
  acoustic power in quiet regions is expected as a result of "inelastic"
  scattering of acoustic waves by the random ensembles of widely spaced
  magnetic flux tubes. The outcome of the effect strongly depends on the
  magnetic filling factor of medium, phi (the total fraction of observed
  area occupied by fluxes) and the parameters of acoustic wave. It is
  most efficient in those regions of quiet Sun where k(2R^2&lt;&lt;) phi
  , R being the characteristic radius of a magnetic flux tube. In this
  case, resonant interaction is the most important of several physical
  processes contribute to the energy exchange between the wave and
  medium. Due to an effect similar to Landau damping, the energy of the
  incident acoustic wave is accumulated in the system of magnetic flux
  tubes and causes the acoustic wave (of frequency omega ) to damp at a
  rate nu_L =~ phi omega . The energy remains for a long time in the form
  of flux-tube oscillations. Then, in a time nu_ {rad}(-1) , the resonant
  flux tubes radiate their energy as a secondary acoustic waves, where the
  radiative damping rate (or the rate of the emission of secondary waves),
  nu_ {rad} =~ omega k(2) R(2) . The power of emitted waves expressed
  in terms of the parameters of the medium allows one to specify the
  regions of an efficient energy input and corresponding range of wave
  parameters. This research is supported by NASA contract NAG5-3077 at
  Stanford University and NASA contract NAS8-39747 at Lockheed Martin.

Title: High-resolution spectral imaging of the Sun in the far
    ultraviolet
Authors: Bruner, Marilyn E.; Tarbell, Theodore D.; Title, Alan M.;
   Wuelser, J. -P.; Handy, Brian N.; Zukic, Muamer
Bibcode: 1996SPIE.2804..249B
Altcode:
  The Transition Region and Coronal Explorer instrument (TRACE) will
  use narrow-band interference filters together with other appropriate
  band limiting elements to make high resolution images of the Sun in
  the C IV lines at 154.8 and 155.0 nm. Filter observations of solar
  C IV emission are complicated by the presence of UV Continuum and
  nearby chromospheric lines because of the relatively wide bandpasses
  of the narrowest currently available interference filters. TRACE will
  use a series of filters to estimate the effects of the UV continuum
  and the long-wavelength `leaks' in the blocking filters which we
  show are the most important contaminants in the C IV images. Further
  improvements in filtergraph performance may be realized through the use
  of tunable Fabry-Perot etalons, which have been under development at
  Lockheed-Martin. We present test data from a cultured quartz etalon
  designed for 155 nm, and will discuss the prospects for etalons
  operation at substantially shorter wavelengths.

Title: Precision pointing and image stabilization for the transition
    region and coronal explorer solar observatory
Authors: Zimbelman, Darrell; Burt, Joseph; Bruner, Marilyn E.; Tarbell,
   Theodore D.; Edwards, Chris G.; Chen, J. R.
Bibcode: 1996SPIE.2739...77Z
Altcode:
  This paper presents a detailed description of the precision pointing
  system and the image stabilization system (ISS) for the Transition
  Region and Coronal Explorer (TRACE) satellite mission. The TRACE
  spacecraft is the fourth in NASA's small explorer series of missions
  and is scheduled for launch in September 1997. The primary TRACE
  science objective is to explore the relationship between the fine scale
  magnetic fields in the solar surface and features in the photosphere,
  chromosphere, transition region and corona. Quantitative images of
  these regions will be collected and used to study the structure and
  evolution of the sun's magnetic field with a spatial and temporal
  resolution of one arc-second and one second, respectively. TO meet
  the science objectives, the instrument payload and the spacecraft
  attitude control system are coupled using a guide telescope. The guide
  telescope provides both the targeting mechanism and pointing error
  signals for the spacecraft feedback control system. In addition, the
  guide telescope generates signals used to control the active mirror
  of the ISS. Simulation results show that precision target pointing is
  maintained to less than 5 arc-seconds, while analysis indicates that
  the ISS reduces image motion jitter below the 0.1 arc- second level.

Title: Coordinated SOHO Observations of Polar Plumes
Authors: Deforest, C. E.; Scherrer, P. H.; Tarbell, T.; Harrison,
   R. A.; Fludra, A.; Delaboudiniere, J. P.; Gurman, J. B.; Wilhelm,
   K.; Lemaire, P.; Hassler, D. M.; Kohl, J. L.; Noci, G.; Fineschi,
   S.; Brueckner, G. E.; Howard, R. A.; Cyr, O. C. St.
Bibcode: 1996AAS...188.4909D
Altcode: 1996BAAS...28R.898D
  On 7 and 8 March 1996, SOHO instruments engaged in their first
  joint science operation, a 12-hr observation of polar plumes
  over the South polar coronal hole. The observing mini-campaign
  included observations from SOHO, other spacecraft, and ground-based
  observatories. Contributing SOHO instruments -- in order of altitude,
  MDI, CDS, SUMER, EIT, UVCS, and LASCO -- made overlapping, simultaneous
  observations of plume structures from the photosphere out to the
  LASCO C3 limit of 32 solar radii. MDI provided line-of-sight surface
  magnetograms with a one-min cadence and 0.6 arcsec resolution;
  CDS, SUMER, and EIT supplied temperature-sensitive images of the
  lower corona with varying cadences and resolutions; UVCS measured
  fluctuations in Ly B intensity across the coronal hole with a one-min
  cadence at 1.4 R0; and LASCO imaged the entire corona out to 30 R0 in
  various visible passbands. Plume footpoints in the lower corona are
  observed by EIT and CDS to vary by a factor of two in EUV brightness
  with a timescale of tens of minutes, while the structures above are
  (as as been previously observed) quiescent on at least a ten-hr time
  scale. We present preliminary results of cross-instrument analysis
  of the observed plumes, and suggest how this and similar future data
  sets can be used to constrain quiet-sun wind acceleration and coronal
  heating models for the coronal hole. This research is supported by
  the SOI-MDI NASA contract NAG5-3077 at Stanford University. SOHO is
  project of international cooperation between NASA and ESA.

Title: The MDI Structure Program: Continuous Monitoring of the
    Solar Interior
Authors: Bush, R. I.; Bogart, R. S.; Hoeksema, J. T.; Kosovichev,
   A. G.; Scherrer, P. H.; Mathur, D.; Morrison, M.; Tarbell, T. D.
Bibcode: 1996AAS...188.3708B
Altcode: 1996BAAS...28..878B
  The Structure Program for the Michelson Doppler Imager instrument
  on SOHO is designed to provide valuable helioseismic observations
  through a continuously operating 5 kbps telemetry channel. Only about
  3% of the total MDI raw data can be transmitted without interruption
  to the ground. Therefore, extensive data processing must be performed
  by the MDI instrument in order produce data products that will fit
  into the restricted telemetry and to meet the scientific observing
  requirements. The Structure Program consists of five observing programs:
  the Medium-l Velocity, Low-l (LOI) Velocity and Intensity, Limb Figure,
  Flux Budget, and Magnetic Proxy. These programs generate spatial
  and temporal averages of three of the MDI full disk observables:
  the velocity, computed continuum intensity, and the computed line
  depth. The performance of these filters will be described. The
  goal of the Medium-l Program is to provide reliable measurements
  of solar p-modes in the range of the angular degree, l, from 0 to
  300, by generating a 23,000 bin spatial average of the full disk
  velocity. The Low-l Program re-bins the velocity and continuum intensity
  images into 180 bins, with the intent of observing long period global
  oscillations. The other three Structure Observations are averaged over
  24 minutes with a 12 minute sample time. The Limb Figure extracts a 14
  arcsecond annulus at the Sun's limb in order to study long wavelength
  oscillations in the observed limb. The Flux Budget and Magnetic Proxy
  are 128 by 128 pixel re-bins of the continuum intensity and line depth
  observables respectively, to study the solar luminosity and large
  scale features. Extensive tests of the individual components of the
  Structure Program have been performed during the commissioning phase of
  the SOHO operation. Uninterrupted operation started in April 1996. This
  research is supported by NASA contract NAG5-3077 at Stanford University.

Title: TRACE: the Transition Region and Coronal Explorer
Authors: Schrijver, C.; Title, A.; Acton, L.; Bruner, M.; Fischer,
   R.; Golub, L.; Harrison, R.; Lemen, J.; Rosner, R.; Scharmer, G.;
   Scherrer, P.; Strong, K.; Tarbell, T.; Wolfson, J.
Bibcode: 1996AAS...188.6704S
Altcode: 1996BAAS...28..934S
  The TRACE mission is designed to obtain images of the solar
  transition region and corona of unprecedented quality. With these
  images we will be able to explore quantitatively the connections
  between the photospheric magnetic field and the associated hot and
  tenuous structures in the outer atmosphere. The TRACE telescope has
  an aperture of 30 cm, and will observe an 8.5 x 8.5 arcminute field of
  view with a resolution of one arcsecond. Finely tuned coatings on four
  quadrants on the primary and secondary normal--incidence mirrors will
  allow observations in narrow EUV and UV spectral bands. The passbands
  are set to Fe IX, XII, and XV lines in the EUV band, while filters
  allow observations in C IV, Ly alpha , and the UV continuum using
  the UV mirror quadrant. The data thus cover temperatures from 10(4)
  K up to 10(7) K. The Sun--synchronous orbit allows long intervals of
  uninterrupted viewing. Observations at different wavelengths can be
  made in rapid succession with an alignment of 0.1 arcsec. Coordinated
  observing with TRACE, SoHO and YOHKOH will give us the first opportunity
  to observe all temperature regimes in the solar atmosphere, including
  magnetograms, simultaneously from space. TRACE is currently scheduled
  to be launched in October 1997. More information can be found on the
  web at ``http://pore1.space.lockheed.com/TRACE/welcome.html''.

Title: Initial Results from SOI/MDI High Resolution Magnetograms
Authors: Title, A.; Tarbell, T.; Frank, Z.; Schrijver, C.; Shine,
   R.; Wolfson, J.; Zayer, I.; Scherrer, P.; Bush, R.; Deforest, C.;
   Hoeksema, T.
Bibcode: 1996AAS...188.6915T
Altcode: 1996BAAS...28..938T
  The Michelson Doppler Imager (MDI) on SoHO takes magnetogram
  s with resolutions of 1.2 (high resolution) and 4 (full disk)
  arcseconds. Movies of 16 hour duration have been constructed in full
  disk and high resolution mode. High resolution movies of the south
  polar region also have been obtained. In sums of nine high resolution
  magnetograms it is possible to detect fields as low as 5 gauss and
  total fluxes as low as 5 10(1) 6 Mx. In mid latitude regions new flux
  is observed to emerge everywhere. At all latitudes below 60 degrees
  flux is mixed on the scale of supergranulation. In the polar region
  above 60 degrees only fields of a single polarity are observed above
  the detection limit.

Title: Preliminary SOI/MDI Observations of Surface Flows by
    Correlation Tracking in the Quiet Solar Photosphere and an Emerging
    Active Region
Authors: Tarbell, T.; Frank, Z.; Hurlburt, N.; Saba, J.; Schrijver,
   C.; Shine, R.; Title, A.; Simon, G.; Strous, L.
Bibcode: 1996AAS...188.6914T
Altcode: 1996BAAS...28..937T
  The extended observation of the solar surface with frequent sampling
  provided by MDI on SoHO offers the chance to observe the evolution of
  supergranules and to measure surface flows associated with active
  regions and perhaps larger scale zonal and meridonal flows. We
  have used local correlation tracking of the granulation pattern for
  measuring surface flows from MDI high resolution continuum images. The
  datasets consist of 1024 x 1024 pixel images collected with a cadence
  of one minute and extending many hours each. The images are typically
  centered upon the central meridian of the sun and offset to the north
  of sun center, spanning roughly 40 degrees of solar longitude and from
  approximately -10 to +30 degrees of solar latitude. The latitude
  dependence of the differential rotation is evident. We present
  preliminary results of our search for signatures of mesogranules,
  supergranules and giant cells. On 23 Feb. 1996, we obtained a 12-hour
  continuous sequence including quiet sun near disk center and NOAA
  region 7946 at about N08 E30. The active region grew rapidly over this
  interval, forming several sunpots. We show preliminary comparisons of
  the measured flow fields with coaligned SOI/MDI magnetograms taken
  at 15-minute intervals. The SOI/MDI program is supported by NASA
  grant NAG5-3077.

Title: SOI/MDI Measurements of Horizontal Flows in the South Polar
    Region of the Sun by Correlation Tracking and Doppler Shifts
Authors: Simon, G.; Frank, Z.; Hurlburt, N.; Schrijver, C.; Shine,
   R.; Tarbell, T.; Title, A.; Deforest, C.
Bibcode: 1996AAS...188.6913S
Altcode: 1996BAAS...28R.937S
  On 7 March 1996, the SOHO spacecraft was offset from its usual
  disk center pointing for an 11-hour observation of the South
  Polar region. MDI took a continuous time series of high resolution
  longitudinal magnetograms during this period, in support of the
  SOHO-wide Joint Observing Program on polar plumes. It also ran several
  hours each of two other programs: one to map the horizontal flows near
  the pole by correlation tracking and Doppler shifts, and another to
  study wave propagation (e.g., by time-distance helioseismology) at
  these high latitudes. In this poster we present preliminary results
  from the first program. Both techniques yield measurements of the
  differential rotation profile near the pole and of horizontal flows of
  supergranulation. These results are compared with each other and with
  corresponding measurements in low latitudes. The location of magnetic
  features in the horizontal flows is also shown. The SOI/MDI program
  is supported by NASA grant NAG5-3077.

Title: Calibration and Performance of the Michelson Doppler Imager
    on SOHO.
Authors: Zayer, I.; Morrison, M.; Tarbell, T. D.; Title, A.; Wolfson,
   C. J.; MDI Engineering Team; Bogart, R. S.; Bush, R. I.; Hoeksema,
   J. T.; Duvall, T.; Sa, L. A. D.; Scherrer, P. H.; Schou, J.
Bibcode: 1996AAS...188.3712Z
Altcode: 1996BAAS...28..879Z
  The Michelson Doppler Imager (MDI) instrument probes the interior
  of the Sun by measuring the photospheric manifestations of solar
  oscillations. MDI was launched in December, 1995, on the Solar and
  Heliospheric Observatory (SOHO) and has been successfully observing the
  Sun since then. The instrument images the Sun on a 1024 x 1024 pixel CCD
  camera through a series of increasingly narrow spectral filters. The
  final elements, a pair of tunable Michelson interferometers, enable
  MDI to record filtergrams with FWHM bandwidth of 94 m Angstroms with
  a resolution of 4 arcseconds over the whole disk. Images can also be
  collected in MDI's higher resolution (1.25 arcsecond) field centered
  about 160 arcseconds north of the equator. An extensive calibration
  program has verified the end-to-end performance of the instrument
  in flight. MDI is working very well; we present the most important
  calibration results and a sample of early science observations. The
  Image Stabilization System (ISS) maintains overall pointing to
  better than ca. 0.01 arcsec, while the ISS' diagnostic mode allows
  us to measure spectrally narrow pointing jitter down to less than
  1 mili-arcsec. We have confirmed the linearity of each CCD pixel to
  lie within 0.5%\ (the FWHM of the distribution is 0.2% ), and have to
  date not detected any contamination on the detector, which is cooled
  to -72 C. The noise in a single Dopplergram is of the order of 20 m/s,
  and initial measurements of transverse velocities are reliable to 100
  m/s. The sensitivity of magnetograms reach 5G in a 10 minute average
  (15G in a single magnetogram). MDI's primary observable, the p-modes
  from full-disk medium-l data, are of very high quality out to l=300
  as seen in the initial l-nu diagram. The SOI-MDI program is supported
  by NASA contract NAG5-3077.

Title: Phenomena in an emerging active region. I. Horizontal dynamics.
Authors: Strous, L. H.; Scharmer, G.; Tarbell, T. D.; Title, A. M.;
   Zwaan, C.
Bibcode: 1996A&A...306..947S
Altcode:
  Horizontal dynamics in observations of NOAA AR 5617 are studied by
  tracking individual elements through the field of view. Small magnetic
  elements of both magnetic polarities occur everywhere in the active
  region, and define unipolar thread-like concentrations of magnetic
  field of up to 15Mm length. The horizontal granular flow field in
  the active region is divergent (e-time scale 2.1hours) and clockwise
  (time scale 32hours). Facular elements are tracers of (clumps of)
  fluxtubes. A hierarchy of movement of magnetic elements appears:
  Facular elements everywhere in the active region move obliquely toward
  the edges of the active region of the same polarity as their own, faster
  than those edges (as defined by strings of pores) move apart. The pores
  move along the edges toward the major sunspots of their own polarity,
  and the major sunspots of either polarity move apart. The separation
  velocity of both polarities of facular elements is about 0.84km/s, of
  pores about 0.73km/s, and that of the major sunspots is about 0.50km/s.

Title: Relative Altitude of Hot and Cool Post-Flare Loops
Authors: van Driel-Gesztelyi, L.; Schmieder, B.; Wiik, J. E.; Tarbell,
   T.; Heinzel, P.; Kitai, R.; Funakoshi, Y.; Anwar, B.
Bibcode: 1996ASPC..111..359V
Altcode: 1997ASPC..111..359V
  The authors collected a unique set of data obtained simultaneously at
  4 different ground based observatories and with the Yohkoh satellite
  to study the relationship between hot X-ray and cool Hα post-flare
  loops as they evolved during the long gradual phase of the X3.9 flare
  which occurred on 25 June 1992. They found reasonably good agreement
  between the computed 'theoretical' cooling times and the 'observed'
  cooling times derived from the relative altitudes of hot and cool
  loops. Taking into account evolutionary effects, the authors also found
  similar shape and configuration of hot and cool loops during the entire
  observing period and confirmed that at any time hot loops are at higher
  altitude than cool loops, suggesting that cool loops indeed descend
  from hot loops. The results provide support for the reconnection model.

Title: Heating of Active Region Corona by Transient Brightenings
    (Microflares)
Authors: Shimizu, T.; Tsuneta, T.; Title, A.; Tarbell, T.; Shine,
   R.; Frank, Z.
Bibcode: 1996mpsa.conf...37S
Altcode: 1996IAUCo.153...37S
  No abstract at ADS

Title: The Solar Oscillations Investigation - Michelson Doppler Imager
Authors: Scherrer, P. H.; Bogart, R. S.; Bush, R. I.; Hoeksema, J. T.;
   Kosovichev, A. G.; Schou, J.; Rosenberg, W.; Springer, L.; Tarbell,
   T. D.; Title, A.; Wolfson, C. J.; Zayer, I.; MDI Engineering Team
Bibcode: 1995SoPh..162..129S
Altcode:
  The Solar Oscillations Investigation (SOI) uses the Michelson Doppler
  Imager (MDI) instrument to probe the interior of the Sun by measuring
  the photospheric manifestations of solar oscillations. Characteristics
  of the modes reveal the static and dynamic properties of the
  convection zone and core. Knowledge of these properties will improve
  our understanding of the solar cycle and of stellar evolution. Other
  photospheric observations will contribute to our knowledge of the
  solar magnetic field and surface motions. The investigation consists
  of coordinated efforts by several teams pursuing specific scientific
  objectives.

Title: The TRACE Mission
Authors: Title, A.; Bruner, M.; Jurcevich, B.; Lemen, J.; Strong,
   K.; Tarbell, T.; Wolfson, J.; Golub, L.; Fisher, R.
Bibcode: 1995AAS...18710107T
Altcode: 1995BAAS...27.1427T
  We have seen significant progress in the flight preparation of the
  TRACE (Transition Region and Coronal Explorer) instrument during
  the last few months. TRACE, approved for 1997 launch, will collect
  images of solar plasmas at temperatures from 10(4) to 10(7) K, with
  one arc second spatial resolution and excellent temporal resolution
  and continuity. TRACE will explore the connections between fine-scale
  magnetic fields and plasma structures in the coronal, transition
  zone and temperature minimum regions of the sun. The 1997 launch
  opportunity allows for collaborative observations from Earth orbit
  with the SoHO instruments stationed at L1. Simultaneous observations
  including high-resolution images, spectra, and magnetograms are
  possible. The 30 cm aperture TRACE telescope uses four normal-incidence
  coatings for the EUV and UV on quadrants of the primary and secondary
  mirrors. Interference filters further isolate 5 different UV bands. The
  images are coaligned and internally stabilized against spacecraft
  jitter. A 1024 x 1024 CCD detector collects images over an 8.5 x 8.5
  arc minute field-of-view. TRACE is launched on a GSFC SMEX spacecraft
  into a Sun-synchronous orbit. It will operate in coordination with
  the SoHO Experiment Operations Facility at GSFC. We are committed to
  maintaining an publicly accessible data base for TRACE data. Browsing
  and data set requesting capabilities will be included at our World
  Wide Web site (see http://www.space.lockheed.com/TRACE/welcome.html).

Title: Precise Photometry Mission -- Measuring Stellar
    Microvariability from Space
Authors: Brown, T. M.; Borucki, W.; Frandsen, S.; Gilliland, R. L.;
   Jones, A.; Noyes, R. W.; Tarbell, T.; Title, A.; Ulrich, R. K.
Bibcode: 1995AAS...187.7111B
Altcode: 1995BAAS...27R1385B
  Atmospheric scintillation limits the precision attainable by
  ground-based photometry; this limitation is a major obstacle to
  progress in several fields, notably asteroseismology of Sun-like
  stars. A space-borne photometric telescope could operate near the shot
  noise limit, removing this obstacle and providing new opportunities
  for inquiry. As part of the program for New Mission Concepts in
  Astrophysics, we are studying the scientific rewards and technological
  challenges associated with a Precise Photometry Mission (PPM). The
  baseline performance goal for the PPM is to measure solar-like
  pulsations (amplitude 3 mu mag) in G stars in the Hyades with a S/N
  ratio of 4 in 10 days of observing time. This performance would also
  allow detection of transits of Earth-sized planets of main-sequence
  stars, extremely precise characterization of the light curves of
  micro-lensing events, and other novel applications. The technical
  approach envisioned for the PPM is wide-band CCD photometry. The study
  that is underway focuses on two aspects of the required technology: (1)
  Are CCD detectors able to provide the necessary very high S/N within
  the spacecraft operating environment? (2) Can new lightweight mirror
  and telescope structure technology be applied to yield significant
  reductions in mission cost? We are addressing both questions with
  laboratory tests, including time-series performance tests of suitable
  CCDs, and thermal and mechanical tests of a SiC telescope mirror. In
  addition to describing PPM's scientific aims and technical rationale,
  we report preliminary results of the CCD tests.

Title: Motion and Evolution of Solar Magnetic Elements
Authors: Berger, T. E.; Schrijver, C. J.; Shine, R. S.; Tarbell,
   T. D.; Title, A. M.; Scharmer, G.
Bibcode: 1995AAS...18710104B
Altcode: 1995BAAS...27.1426B
  The dynamics of sub-arcsecond solar magnetic flux tubes are analyzed
  based on very-high resolution movies of photospheric bright points
  obtained in 1994 at the 50-cm Swedish Solar Vacuum Telescope (SVST)
  on the island of La Palma, Spain. The bright points are imaged using
  a 12 Angstroms bandpass interference filter centered at 4305 Angstroms
  in the ``G Band'' molecular bandhead of the CH molecule. The image sets
  typically consist of up to 4 hours of consecutive images taken at a 10
  to 20 second cadence. Spatial resolution throughout the movies averages
  less than 0\arcsec.5 and many frames in the sets exhibit resolution
  down to 0\arcsec.25. Magnetic flux elements in the photosphere are
  shown to move continually along the intergranular lanes at speeds
  of up to 5 km/sec and ranges up to several thousand km. Evolution of
  individual magnetic elements is dominated by the local evolution of
  surrounding granules. Fragmentation and merging is the fundamental
  mode of evolution of the majority of magnetic elements seen in our
  data. Rotation and folding of chains or groups of elements is also
  frequently observed. The time scale for the fragmentation/merging
  evolution of the elements is on the order of the lifetime of granulation
  (6--8 minutes), but significant morphological changes are seen to
  occur on time scales as short as 100 seconds. The concept of a stable,
  isolated, sub-arcsecond magnetic flux element in the solar photosphere
  is inconsistent with the observations presented here.

Title: Solar Lite
Authors: Rosenberg, W. J.; Title, A. M.; Tarbell, T. D.
Bibcode: 1995AAS...187.7406R
Altcode: 1995BAAS...27.1390R
  Solar Lite is a one meter diameter Gregorian diffraction limited
  solar telescope using Silicon Carbide optics that is currently being
  fabricated by the Vavilov Optical Institute in St. Petersburg,
  Russia. The mirror is made of a two phase ceramic that is 83%
  SiC and 17% Si. A 63 cm, f/1.5 test sphere has been fabricated and
  polished. The test mirror weighs 12 Kg, the surface error 1/40 wave RMS,
  and the surface roughness is 18 angstroms RMS. The telescope structure
  is a corrugated aluminum tube (bellows) with Invar stringers. This
  approach is possible because Russian material technology is capable
  of producing thin Invar sheets with a coefficient of linear expansion
  of 3x10(-7) . The primary mirror has a design weight of 30 kg and the
  entire telescope has a total weight of 150 kg. A preliminary design
  review has been completed. The detailed design of the telescope will be
  completed in January 1996. We hope to fly the telescope with a vector
  magnetograph in a sun synchronous orbit. The completion date for the
  telescope is July 1997.

Title: New Observations of Subarcsecond Photospheric Bright Points
Authors: Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell,
   T. D.; Title, A. M.; Scharmer, G.
Bibcode: 1995ApJ...454..531B
Altcode:
  We have used an interference filter centered at 4305 Å within the
  bandhead of the CH radical (the "G band") and real-time image selection
  at the Swedish Vacuum Solar Telescope on La Palma to produce very
  high contrast images of subarcsecond photospheric bright points at all
  locations on the solar disk. During the 6 day period of 1993 September
  15-20 we observed active region NOAA 7581 from its appearance on the
  East limb to a near disk-center position on September 20. A total of
  1804 bright points were selected for analysis from the disk center image
  using feature extraction image processing techniques. The measured FWHM
  distribution of the bright points in the image is subnormal with a modal
  value of 220 km (0".30) and an average value of 250 km (0".35). The
  smallest measured bright point diameter is 120 km (0".17) and the
  largest is 600 km (0".69). Approximately 60% of the measured bright
  points are circular (eccentricity ∼1.0), the average eccentricity
  is 1.5, and the maximum eccentricity corresponding to filigree in
  the image is 6.5. The peak contrast of the measured bright points is
  normally distributed. The contrast distribution variance is much greater
  than the measurement accuracy, indicating a large spread in intrinsic
  bright-point contrast. When referenced to an averaged "quiet-Sun area 1n
  the image, the modal contrast is 29% and the maximum value is 75%; when
  referenced to an average intergranular lane brightness in the image,
  the distribution has a modal value of 61 % and a maximum of 119%. The
  bin-averaged contrast of G-band bright points is constant across the
  entire measured size range. The measured area of the bright points,
  corrected for population and selection effects, covers about 1.8% of
  the total image area. Large pores and micropores occupy an additional
  2% of the image area, implying a total area fraction of magnetic
  proxy features in the image of 3.8%. We discuss the implications of
  this area fraction measurement in the context of previously published
  measurements which show that typical active region plage has a magnetic
  filling factor on the order of 10% or greater. The results suggest that
  in the active region analyzed here, less than 50% of the small-scale
  magnetic flux tubes are demarcated by visible proxies such as bright
  points or pores.

Title: Vorticity and Divergence in the Solar Photosphere
Authors: Wang, Yi; Noyes, Robert W.; Tarbell, Theodore D.; Title,
   Alan M.
Bibcode: 1995ApJ...447..419W
Altcode:
  We have studied an outstanding sequence of continuum images of the
  solar granulation from Pic du Midi Observatory. We have calculated the
  horizontal vector flow field using a correlation tracking algorithm,
  and from this determined three scalar fields: the vertical component of
  the curl, the horizontal divergence, and the horizontal flow speed. The
  divergence field has substantially longer coherence time and more power
  than does the curl field. Statistically, curl is better correlated
  with regions of negative divergence that is, the vertical vorticity is
  higher in downflow regions, suggesting excess vorticity in intergranular
  lanes. The average value of the divergence is largest (i.e., outflow
  is largest) where the horizontal speed is large; we associate these
  regions with exploding granules. A numerical simulation of general
  convection also shows similar statistical differences between curl
  and divergence. Some individual small bright points in the granulation
  pattern show large local vorticities.

Title: The Transition Region and Coronal Explorer (trace)
Authors: Title, A.; Bruner, M.; Jurcevich, B.; Lemen, J.; Strong,
   K.; Tarbell, T.; Wolfson, J.; Golub, L.; Bookbinder, J.; Fisher, R.
Bibcode: 1995ESASP.376b.505T
Altcode: 1995help.confP.505T; 1995soho....2..505T
  No abstract at ADS

Title: Soi/mdi Studies of Active-Region Seismology and Evolution
Authors: Tarbell, T. D.; Title, A.; Hoeksema, J. T.; Scherrer, P.;
   Zweibel, E.
Bibcode: 1995ESASP.376b..99T
Altcode: 1995help.confP..99T; 1995soho....2...99T
  The Solar Oscillations Investigation (SOI) will study active regions
  in many ways using both helioseismic and conventional observing
  techniques. The Michelson Doppler Imager (MDI) instrument can
  make Doppler, continuum and line depth images and also longitudinal
  magnetograms, showing either the full disk or a high resolution field of
  view. There will be a Dynamics Program of continuous full disk Doppler
  observations for two months per year, many Campaign Programs of 8 hours
  continuous observing per day, and a synoptic Magnetic Program of about
  15 full disk magnetograms per day. This paper gives a brief description
  of some of the scientific plans, measurements, and observing programs.

Title: Solar Irradiance Variations due to Active Region Faculae
Authors: Topka, K. P.; Tarbell, T. D.; Title, A. M.
Bibcode: 1995SPD....26..512T
Altcode: 1995BAAS...27..959T
  No abstract at ADS

Title: Frame Selection Techniques for Solar Movies
Authors: Shine, R. A.; Tarbell, T.; Title, A.; Scharmer, G.; Simon,
   G.; Brandt, P.; Berger, T.
Bibcode: 1995SPD....26..506S
Altcode: 1995BAAS...27..957S
  No abstract at ADS

Title: Flux Emergence in a Sunspot Moat and Young Active Region
Authors: Title, A. M.; Frank, Z. A.; Shine, R. A.; Tarbell, T. D.;
   Simon, G. W.; Brandt, P. N.
Bibcode: 1995SPD....26.1007T
Altcode: 1995BAAS...27..978T
  No abstract at ADS

Title: Properties of Sub-Arcsecond Facular Bright Points
Authors: Berger, T.; Schrijver, C.; Shine, R.; Tarbell, T.; Title,
   A.; Scharmer, G.
Bibcode: 1995SPD....26..505B
Altcode: 1995BAAS...27..957B
  No abstract at ADS

Title: Michelson Doppler Imager (MDI) Performance Characteristics
Authors: Zayer, I.; Morrison, M.; Pope, T.; Rosenberg, W.; Tarbell,
   T.; Title, A.; Wolfson, J.; Bogart, R. S.; Hoeksema, J. T.; Milford,
   P.; Scherrer, P. H.; Schou, J.
Bibcode: 1995ASPC...76..456Z
Altcode: 1995gong.conf..456Z
  No abstract at ADS

Title: Observations of Convection
Authors: Title, A. M.; Hurlburt, N.; Schrijver, C.; Shine, R.;
   Tarbell, T.
Bibcode: 1995ESASP.376a.113T
Altcode: 1995heli.conf..113T; 1995soho....1..113T
  The primary goal of the Solar Oscillations Investigation is
  to understand the interior of the Sun using the techniques of
  helioseismology. In addition the Michelson Doppler Imager produces
  images of the solar surface with sufficient resolution to measure
  surface flows via the technique of local correlation tracking and
  magnetograms which allow feature tracking of magnetic fields. It will
  be possible to measure the evolution of meso and supergranulation, the
  evolution of the meso and supergranulation patterns, and the motion of
  magnetic elements in the flow field. With observing periods of 8 hours
  one should be able to detect large scale flow fields of 10 m/s second
  or less. The magnetograms will provide the data to understand how the
  cell patterns evolve as a function of magnetic field configuration.

Title: Status of the Solar Oscillations Investigation - Michelson
    Doppler Imager
Authors: Scherrer, P. H.; Bogart, R. S.; Bush, R. I.; Hoeksema,
   J. T.; Milford, P.; Schou, J.; Pope, T.; Rosenberg, W.; Springer,
   L.; Tarbell, T.; Title, A.; Wolfson, J.; Zayer, I.
Bibcode: 1995ASPC...76..402S
Altcode: 1995gong.conf..402S
  No abstract at ADS

Title: The transition region and coronal explorer (TRACE)
Authors: Tarbell, T. D.; Bruner, M.; Jurcevich, B.; Lemen, J.; Strong,
   K.; Title, A.; Wolfson, J.
Bibcode: 1994ESASP.373..375T
Altcode: 1994soho....3..375T
  No abstract at ADS

Title: On the Relation Between Facular Bright Points and the
    Magnetic Field
Authors: Berger, Thomas; Shine, Richard; Tarbell, Theodore; Title,
   Alan; Scharmer, Goran
Bibcode: 1994AAS...185.8607B
Altcode: 1994BAAS...26.1465B
  Multi-spectral images of magnetic structures in the solar photosphere
  are presented. The images were obtained in the summers of 1993 and
  1994 at the Swedish Solar Telescope on La Palma using the tunable
  birefringent Solar Optical Universal Polarimeter (SOUP filter), a 10
  Angstroms wide interference filter tuned to 4304 Angstroms in the band
  head of the CH radical (the Fraunhofer G-band), and a 3 Angstroms wide
  interference filter centered on the Ca II--K absorption line. Three
  large format CCD cameras with shuttered exposures on the order of
  10 msec and frame rates of up to 7 frames per second were used to
  create time series of both quiet and active region evolution. The
  full field--of--view is 60times 80 arcseconds (44times 58 Mm). With
  the best seeing, structures as small as 0.22 arcseconds (160 km) in
  diameter are clearly resolved. Post--processing of the images results
  in rigid coalignment of the image sets to an accuracy comparable to the
  spatial resolution. Facular bright points with mean diameters of 0.35
  arcseconds (250 km) and elongated filaments with lengths on the order
  of arcseconds (10(3) km) are imaged with contrast values of up to 60
  % by the G--band filter. Overlay of these images on contemporal Fe I
  6302 Angstroms magnetograms and Ca II K images reveals that the bright
  points occur, without exception, on sites of magnetic flux through the
  photosphere. However, instances of concentrated and diffuse magnetic
  flux and Ca II K emission without associated bright points are common,
  leading to the conclusion that the presence of magnetic flux is a
  necessary but not sufficient condition for the occurence of resolvable
  facular bright points. Comparison of the G--band and continuum images
  shows a complex relation between structures in the two bandwidths:
  bright points exceeding 350 km in extent correspond to distinct
  bright structures in the continuum; smaller bright points show no
  clear relation to continuum structures. Size and contrast statistical
  cross--comparisons compiled from measurements of over two-thousand
  bright point structures are presented. Preliminary analysis of the time
  evolution of bright points in the G--band reveals that the dominant mode
  of bright point evolution is fission of larger structures into smaller
  ones and fusion of small structures into conglomerate structures. The
  characteristic time scale for the fission/fusion process is on the
  order of minutes.

Title: Facular Contrast and Hot Wall Models of Flux Tubes
Authors: Topka, K. P.; Tarbell, T. D.; Title, A. M.
Bibcode: 1994AAS...185.8606T
Altcode: 1994BAAS...26.1465T
  Solar rotation causes features on its surface to be viewed at different
  angles. The appearance of active region faculae changes dramatically
  with viewing angle. They have minimum contrast at disk center, but
  appear bright near the limb. The nature of this center-limb variation
  is related to the structure of the individual flux tubes comprising
  faculae. One class of models depict a facula as an evacuated flux tube
  with hot walls and a depressed cool floor (hot wall model). Another
  depicts them as hot clouds, because of internal heating. Both can
  explain the observed center-limb variation in contrast. In this paper
  we ask whether there are other observable phenomena that can help
  differentiate between these models. The observations were obtained at
  the Swedish Solar Observatory, La Palma, using the Lockheed tunable
  filter. The data consist of co-registered images of line-of-sight
  magnetic field and of continuum intensity. The correlation between
  strong magnetic field and continuum intensity in active region faculae
  shows a remarkable and reproducible change between heliocentric angles
  of 50deg and 60deg . These results support the hot wall model, but not
  the hot cloud model. Hybrid models in which the flux tube has properties
  of both models cannot by ruled out. This work has been supported by
  NSF contract ATM-9320353, by NASA contracts NASW-4612 and NAS8-39747,
  and by Lockheed IR funds.

Title: On the Temperature and Velocity through the Photosphere of
    a Sunspot Penumbra
Authors: del Toro Iniesta, J. C.; Tarbell, T. D.; Ruiz Cobo, B.
Bibcode: 1994ApJ...436..400D
Altcode:
  We investigate the structure in depth of a sunspot penumbra by means
  of the inversion code of the radiative transfer equation proposed
  by Ruiz Cobo &amp; del Toro Iniesta (1992), applied to a set of
  filtergrams of a sunspot, scanning the Fe I line at 5576.1 A, with
  a sampling interval of 30 mA, from -120 to 120 mA from line center
  (data previously analyzed by Title et al. 1993). The temperature
  structure of this penumbra is obtained for each of the 801 pixels
  selected (0.32 sec x 0.32 sec). On the average, the temperatures seem
  to decrease as we move inward, but the differences are of the order
  of the rms values (approximately equal 100-200 K) at a given distance
  to sunspot center. The outer parts of the penumbra have also a bigger
  curvature in the T versus log tau<SUB>5</SUB> relation than the inner
  parts. We realize, however, that these differences might be influenced
  by possible stray light effects. Compared to the quiet Sun, penumbral
  temperatures are cooler at deep layers and hotter at high layers. A mean
  penumbral model atmosphere is presented. The asymmetries observed in the
  intensity profile (the line is magnetically insensitive) are deduced
  to be produced by strong gradients of the line-of-sight velocity that
  sharply vary spatially along slices of almost constant distance to
  sunspot center. These variations suggest that such gradients are not
  only needed to explain the broadband circular polarization observed
  in sunspots (see Sanchez Almeida &amp; Lites 1992) but are a main
  characteristic of the fine-scale penumbra. The results are compatible
  with an Evershed flow present everywhere, but its gradient with depth
  turns out to vary so that the flow seems to be mainly concentrated in
  some penumbral fibrils when studied through Dopplergrams. Finally,
  as by-products of this study, we put constraints to the practical
  usefulness of the Eddington-Barbier relation, and we explain the values
  of the Fourier Dopplergrams to be carrying information of layers around
  the centroid of the generalized response function of Dopplergrams to
  velocity fluctuations.

Title: Trace — The transition region and coronal explorer
Authors: Strong, K.; Bruner, M.; Tarbell, T.; Title, A.; Wolfson, C. J.
Bibcode: 1994SSRv...70..119S
Altcode:
  TRACE is a single-instrument solar mission that will be put into
  a Sunsynchronous polar orbit and will obtain continuous solar
  observations for about 8 months per year. It will collect images of
  solar plasmas at temperatures from 10<SUP>4</SUP> to 10<SUP>7</SUP>
  K, with 1-arcsec spatial resolution and excellent temporal resolution
  and continuity. With such data, we expect to gain a new understanding
  of many solar and stellar problems ranging from coronal heating to
  impulsive magnetohydrodynamic phenomena.

Title: High-Resolution Observations of the Evershed Effect in Sunspots
Authors: Shine, R. A.; Title, A. M.; Tarbell, T. D.; Smith, K.; Frank,
   Z. A.; Scharmer, Goran
Bibcode: 1994ApJ...430..413S
Altcode:
  High spatial resolution movies of sunspots taken at the Swedish
  Solar Observatory on La Palma reveal that the Evershed effect is time
  dependent. Outward proper motions are visible in both the continuum
  and Dopplergrams. These can be tracked over most of the width of
  the penumbra and overlap regions that show inward moving penubral
  grains. The radial spacing between the moving structures is about 2000
  km, and they exhibit irregular repetitive behavior with a typical
  interval of 10 minutes. These are probably the cause of 10 minutes
  oscillations sometimes seen in a penumbral power spectra. Higher
  velocities are spatially correlated with the relatively darker regions
  between bright filaments. Regions with a strong variation in the Doppler
  signal show peak-to-peak modulations of 1 km/s on an average velocity
  of about 3-4 km/s. The proper motion velocity is approximately constant
  from the iner penumbra and generally larger than the Doppler velocity
  when both are interpreted as projections of horizontal motion. Regions
  where thay are consistent suggest a typical horizontal velocity of
  3.5 km/s. Some proper motion velocites as high as 7 km/s are seen,
  but these are less certain. The temporal behavoir shows a correlation
  between increased Doppler signal and increased continuum intensity,
  the opposite of the spatial correlation. When spatially averaged
  across filaments and over time, the averaged Evershed effect has a peak
  horizontal component near the outer edge of the penumbra of 2.0 km/s
  with evidence for a 200-400 m/s upward component. The latter depends
  on an uncertain absolute velocity calibration. If real it could be
  an actual upward component or a penumbral analogue of the convective
  blueshift seen in the quiet Sun.

Title: Dynamics of the Evershed effect
Authors: Shine, R. A.; Title, A. M.; Tarbell, T. D.; Smith, K.; Frank,
   Z. A.; Scharmer, G.
Bibcode: 1994ASIC..433..197S
Altcode:
  No abstract at ADS

Title: Photospheric origins of chromospheric and coronal activity
Authors: Tarbell, Theodore
Bibcode: 1994lock.reptQ....T
Altcode:
  This contract is for a two-year research study of the origins of
  activity in the upper atmosphere of the sun. The approach is to collect
  high resolution images of the lower atmosphere on observing runs at the
  Swedish Solar Observatory on La Palma, Canary Islands, Spain. The best
  observations are analyzed and compared with data from other telescopes
  and/or theoretical models, to study magnetic flux emergence, coronal
  heating, and various dynamic phenomena and transients. Software for
  analysis and visualization of the data is developed as needed. The
  contract is being performed by the Solar and Astrophysics Laboratory,
  part of the Lockheed Palo Alto Research Laboratory (LPARL) of the
  Research and Development Division (RDD) of Lockheed Missiles and Space
  Co., Inc. (LMSC).

Title: The Solar Oscillation Investigation - Michelson Doppler Imager
    (SOI-MDI)
Authors: Hoeksema, J. T.; Bogart, R. S.; Bush, R. I.; Milford, P. N.;
   Pope, T.; Rosenberg, W.; Scherrer, P. H.; Springer, L.; Tarbell, T.;
   Title, A.; Wolfson, J.; Zayer, I.
Bibcode: 1993BAAS...25.1192H
Altcode:
  No abstract at ADS

Title: Michelson Doppler Imager Calibration and Performance Tests
Authors: Zayer, I.; Bogart, R. S.; Hoeksema, J. T.; Tarbell, T.
Bibcode: 1993BAAS...25.1192Z
Altcode:
  No abstract at ADS

Title: Multitemperature Observations of an Emerging Flux Region
Authors: Bruner, M. E.; Acton, L. W.; Brown, W. A.; Lemen, J. R.;
   Shine, R.; Strong, K. T.; Tarbell, T.; Dulk, G.; Tsuneta, S.; Bastian,
   T.; Dame, L.
Bibcode: 1993BAAS...25.1179B
Altcode:
  No abstract at ADS

Title: Observations of an Emerging Flux Region
Authors: Brown, W. A.; Acton, L. W.; Bruner, M. E.; Lemen, J. R.;
   Shine, R.; Strong, K. T.; Tarbell, T.; Dulk, G.; Tsuneta, S.; Bastian,
   T.; Dame, L.
Bibcode: 1993BAAS...25Q1214B
Altcode:
  No abstract at ADS

Title: The Quiet Sun Network and Solar Irradiance Variations
Authors: Topka, K. P.; Tarbell, T. D.; Title, A. M.
Bibcode: 1993BAAS...25R1183T
Altcode:
  No abstract at ADS

Title: Solar Coronal Magnetic Field Topology Inferred from High
    Resolution Optical and X-ray Movies
Authors: Tarbell, T.; Frank, Z.; Hurlburt, N.; Morrison, M.; Shine,
   R.; Title, A.; Acton, L.
Bibcode: 1993BAAS...25.1208T
Altcode:
  No abstract at ADS

Title: Invited Talk: (Low-Cost Missions in High Resolution Solar
    Physics Using Small Spacecraft)
Authors: Tarbell, T. D.
Bibcode: 1993BAAS...25.1180T
Altcode:
  No abstract at ADS

Title: Vertical Stratification of a Sunspot Penumbra
Authors: del Toro Iniesta, J. C.; Tarbell, T. D.; Ruiz Cobo, B.
Bibcode: 1993BAAS...25Q1221D
Altcode:
  No abstract at ADS

Title: La Palma Observations During the CoMStOC'92 Campaign
Authors: Shine, R.; Tarbell, T.; Topka, K.; Frank, Z.; Title, A.;
   Scharmer, G.
Bibcode: 1993BAAS...25S1223S
Altcode:
  No abstract at ADS

Title: ``The Active Sun'': Educational Videotapes on Solar Physics
    for College Astronomy
Authors: Hurlburt, N.; Title, A.; Tarbell, T.; Frank, Z.; Topka, K.;
   Shine, R.
Bibcode: 1993AAS...182.1002H
Altcode: 1993BAAS...25..809H
  We present a series of short, educational documentaries on solar
  physics aimed at college-level general astronomy courses. These
  tapes highlight recent advances in high-resolution solar astronomy
  and in theoretical and computational modeling of solar physics
  with particular focus on dynamical phenomena. The relevant physical
  mechanisms, theoretical interpretations and observational techniques
  are discussed. These include granulation, the theory of convection,
  five-minute oscillations, sunspots, magnetic fields, seeing and
  dopplergrams. VHS tapes are available to researchers and educators
  through a variety of distributors. This work supported by Lockheed
  Independent Research Funds.

Title: Solar Coronal Magnetic Field Topology Inferred from High
    Resolution Optical and X-ray Movies
Authors: Tarbell, T.; Frank, Z.; Hurlburt, N.; Morrison, M.; Shine,
   R.; Title, A.; Acton, L.
Bibcode: 1993AAS...182.4805T
Altcode: 1993BAAS...25R.880T
  We are using high resolution digital movies of solar active regions
  in optical and X-ray wavelengths to study solar flares and other
  transients. The optical movies were collected at the Swedish Solar
  Observatory on La Palma using the Lockheed tunable filtergraph
  system, in May - July, 1992. They include longitudinal and transverse
  magnetograms, H-alpha Doppler and intensity images at many wavelengths,
  Ca K, Na D, and white light images. Simultaneous X-ray images from
  Yohkoh are available much of the time. We are learning several ways to
  establish the connectivity of some coronal magnetic field lines. Some
  of the clues available are: magnetic footpoint polarities and transverse
  field directions; H-alpha fibrils and loops seen in several wavelengths;
  proper motion and Doppler shifts of blobs moving along field lines;
  footpoint brightening in micro-flares; spreading of flare ribbons
  during gradual phases of flares; X-ray morphology and correlations with
  H-alpha; and draining of flare loops. Examples of each of these will
  be shown on video. This work is supported by NASA Contracts NASW-4612
  and NAS8-37334 and by Lockheed Independent Research Funds.

Title: On the Magnetic and Velocity Field Geometry of Simple Sunspots
Authors: Title, Alan M.; Frank, Zoe A.; Shine, Richard A.; Tarbell,
   Theodore D.; Topka, Kenneth P.; Scharmer, Goran; Schmidt, Wolfgang
Bibcode: 1993ApJ...403..780T
Altcode:
  It is presently shown that a simple sunspot model with azimuthal
  variations in inclination, but lacking azimuthal field-strength
  variations, is free from azimuthal Lorentz forces. The meridional
  currents arising from the inclination variations are parallel to the
  field lines, suggesting that a cylindrically symmetric magnetostatic
  sunspot model can be perturbed into one with azimuthal variations in
  inclination with adjustment of the meridional force balance.

Title: Percolation theory and the geometry of photospheric magnetic
    flux concentrations
Authors: Balke, A. C.; Schrijver, C. J.; Zwaan, C.; Tarbell, T. D.
Bibcode: 1993SoPh..143..215B
Altcode:
  The magnetic field in solar active regions forms a highly structured
  pattern without an apparent length scale. We study this pattern in
  detail for a plage and its surroundings observed with the Swedish Solar
  Observatory on La Palma. The magnetogram has a resolution of about
  1/3″, after image optimisation. We analysed the geometric properties
  of isolated patches of magnetic flux. Patches with a linear size up to
  3″ appear to be statistically self-similar, with a fractal dimension
  ofD<SUB>f</SUB> = 1.54 ± 0.05 for the relation between area and linear
  size. This value agrees very well with the dimensionD<SUB>f</SUB>
  = 1.56 which is found in percolation theory for clusters of tracers
  placed randomly on a lattice with a tracer density below a critical
  threshold. The distribution of observed cluster areas also agrees
  with that of clusters on such a random lattice. The correspondence
  between properties of observations and of clusters on randomly filled
  lattices suggests that- well after emergence - the magnetic flux on
  the Sun is randomly distributed at least up to sizes of about 3″
  and possibly larger.

Title: Observations of High Frequency and High Wavenumber Solar
    Oscillations
Authors: Fernandes, D.; Scherrer, P.; Tarbell, T.; Title, A.
Bibcode: 1993ASPC...42..101F
Altcode: 1993gong.conf..101F
  No abstract at ADS

Title: High Resolution Magnetic Field Measurements in the Sunspot
    Photosphere (Invited)
Authors: Hofmann, A.; Schmidt, W.; Balthasar, H.; Tarbell, T. T.;
   Frank, Z. A.
Bibcode: 1993ASPC...46...11H
Altcode: 1993IAUCo.141...11H; 1993mvfs.conf...11H
  No abstract at ADS

Title: Subsurface Transverse Flows Near an Active Region
Authors: Milford, P. N.; Hill, F.; Tarbell, T. D.
Bibcode: 1993ASPC...42...85M
Altcode: 1993gong.conf...85M
  No abstract at ADS

Title: White-light movies of the solar photosphere from the SOUP
    instrument on Spacelab 2 (Advances in Space Research 1986)
Authors: Title, A. M.; Tarbell, T. D.; Simon, G. W.; Acton, L.;
   Duncan, D.; Ferguson, S.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren,
   R.; Morrill, M.; Pope, T.; Reeves, R.; Rehse, R.; Shine, R.; Topka,
   K.; Harvey, J.; Leibacher, J.; Livingston, W.; November, L.
Bibcode: 1993inas.book..100T
Altcode:
  No abstract at ADS

Title: The solar oscillations investigation - Michelson Doppler
    Imager.
Authors: Hoeksema, J. Todd; Scherrer, P. H.; Bush, R. I.; Title, A.;
   Tarbell, T.
Bibcode: 1992ESASP.348....9H
Altcode: 1992cscl.work....9H
  The Solar Oscillations Investigation (SOI) has developed the Michelson
  Doppler Imager (MDI) to investigate the properties of solar interior
  using the tools of helioseismology and of the photosphere and
  corona using more conventional techniques. A fundamental goal is
  to understand the Sun by determining its structure and observing its
  dynamics. The basic observables, velocity, intensity and magnetic field,
  are computed on board from up to twenty 1024 by 1024 filtergrams made
  each minute. Subsequent analysis will extend the region one can explore
  downward into the solar interior and upward into the corona. While
  the instrument is dedicated to producing an uninterrupted series
  of helioseismology data, several magnetograms will be made each day
  and special 8-hour campaigns are being developed to address specific
  scientific questions, some in coordination with other SOHO instruments.

Title: Polarimetry and spectroscopy of a simple sunspot. I - On the
    magnetic field of a sunspot penumbra
Authors: Schmidt, W.; Hofmann, A.; Balthasar, H.; Tarbell, T. D.;
   Frank, Z. A.
Bibcode: 1992A&A...264L..27S
Altcode:
  We investigate the magnetic field structure of a medium sized sunspot
  using high resolution magnetograms and spectrograms and derive a
  relationship between the brightness of penumbral structures and the
  inclination of the magnetic field. The field inclination to the spot
  normal is larger in the dark structures than in the bright ones. We
  show that the field strength does not vary between dark and bright
  structures. At the inner penumbral boundary the field strength is 2000
  Gauss and about 1000 Gauss at the outer penumbral edge. The line-of
  sight component of the material flow decreases rapidly within one
  arcsecond at the photospheric boundary of the spot.

Title: Properties of the Smallest Solar Magnetic Elements. I. Facular
    Contrast near Sun Center
Authors: Topka, K. P.; Tarbell, T. D.; Title, A. M.
Bibcode: 1992ApJ...396..351T
Altcode:
  Measurements are presented which indicate that the continuum intensity
  of facular areas in solar active regions, outside sunspots and pores, is
  less than that of the quiet sun very near disk center. It is shown that
  the observed continuum intensity of faculae at disk center near 5000
  A is nearly 3 percent less than that of the quiet sun. The continuum
  contrast increases rapidly away from disk center, reaching +2 percent
  at 45 deg. The zero-crossing point, where the contrast changes sign,
  occurs at 20-degree heliocentric angle. This is contrary to many earlier
  observations. The constraint these observations place on the size
  of flux tubes depends upon the value of the zero-crossing point. It
  is proposed that most of the flux tubes in solar faculae may be very
  small, in the range 50-100 km in diameter, and that inclination from
  local vertical of about 10 deg at the photosphere is common on the
  sun. Footpoints of opposite polarity tend to tilt toward one another.

Title: From Filtergrams to Physical Atmospheric Magnitudes: A
    Prospective Diagnostic
Authors: del Toro Iniesta, J. C.; Tarbell, T.; Ruiz Cobo, B.
Bibcode: 1992AAS...181.8115D
Altcode: 1992BAAS...24.1255D
  No abstract at ADS

Title: A solar magnetic and velocity field measurement system for
Spacelab 2: The solar optical universal polarimeter (SOUP)
Authors: Tarbell, Theodore D.; Title, Alan M.
Bibcode: 1992lock.reptS....T
Altcode:
  The Solar Optical Universal Polarimeter flew on the Shuttle Mission
  Spacelab 2 (STS-51F) in August, 1985, and collected historic solar
  observations. SOUP is the only solar telescope on either a spacecraft
  or balloon which has delivered long sequences of diffraction-limited
  images. These movies led to several discoveries about the solar
  atmosphere which were published in the scientific journals. After
  Spacelab 2, reflights were planned on the Space Shuttle Sunlab
  Mission, which was cancelled after the Challenger disaster, and on
  balloon flights, which were also cancelled for funding reasons. In
  the meantime, the instrument was used in a productive program of
  ground-based observing, which collected excellent scientific data
  and served as instrument tests. This report gives an overview of
  the history of the SOUP program, the scientific discoveries, and the
  instrument design and performance.

Title: A solar magnetic and velocity field measurement system for
Spacelab 2: The Solar Optical Universal Polarimeter (SOUP)
Authors: Tarbell, Theodore D.; Title, Alan M.
Bibcode: 1992lock.reptR....T
Altcode:
  The Solar Optical Universal Polarimeter (SOUP) flew on the shuttle
  mission Spacelab 2 (STS-51F) in August, 1985, and collected
  historic solar observations. SOUP is the only solar telescope on
  either a spacecraft or balloon which has delivered long sequences of
  diffraction-limited images. These movies led to several discoveries
  about the solar atmosphere which were published in the scientific
  journals. After Spacelab 2, reflights were planned on the shuttle Sunlab
  mission, which was cancelled after the Challenger disaster, and on a
  balloon flights, which were also cancelled for funding reasons. In
  the meantime, the instrument was used in a productive program of
  ground-based observing, which collected excellent scientific data and
  served as instrument tests. Given here is an overview of the history
  of the SOUP program, the scientific discoveries, and the instrument
  design and performance.

Title: On the Differences between Plage and Quiet Sun in the Solar
    Photosphere
Authors: Title, Alan M.; Topka, Kenneth P.; Tarbell, Theodore D.;
   Schmidt, Wolfgang; Balke, Christiaan; Scharmer, Goran
Bibcode: 1992ApJ...393..782T
Altcode:
  Time sequences of interleaved observations of the continuum intensity,
  longitudinal magnetic field, vertical velocity in the midphotosphere,
  and the line-center intensity in Ni I 6768 A were obtained in an
  active-region plage and the surrounding relatively field-free area near
  disk center. Spacetime Fourier filtering techniques are used to separate
  the convective and oscillatory components of the solar atmosphere. The
  properties of the photosphere are found to differ qualitatively and
  quantitatively between the plage, where the field is 150 G or more,
  and its quiet surroundings. The scale of granulation is smaller, the
  contrast lower, and the temporal evolution slower in the plage than the
  quiet sun. In the plage, the vertical velocity is reduced in amplitude
  compared to the quiet sun, and there is little evidence of a granulation
  pattern, while in the quiet sun the vertical flow pattern is similar in
  size and shape to the underlying granulation pattern in the continuum.

Title: Observations of High-Frequency and High-Wavenumber Solar
    Oscillations
Authors: Fernandes, D. N.; Scherrer, P. H.; Tarbell, T. D.; Title,
   A. M.
Bibcode: 1992ApJ...392..736F
Altcode:
  Doppler shift measurements of the Na D1 absorption line reveal solar
  oscillations in a new regime of frequency and wavenumber. Oscillations
  of vertical velocities in the temperature minimum and low chromosphere
  of the sun are observed with frequencies ranging up to 9.5 mHz. The
  fundamental modes appear with wavenumbers up to 5.33/Mm (equivalent
  spherical harmonic degree 3710). No evidence for chromospheric modes
  of 3-minute period is reported.

Title: Facular Contrast Near Solar Disk Center and the Inclination
    of Magnetic Lines of Force from Local Vertical
Authors: Topka, K. P.; Tarbell, T. D.; Title, A. M.
Bibcode: 1992AAS...180.4004T
Altcode: 1992BAAS...24..793T
  No abstract at ADS

Title: The Solar Oscillation Imager-Michelson Doppler Imager for SoHO
Authors: Title, A.; Tarbell, T.; Wolfson, J.; Scherrer, P.; Bush,
   R.; Hoeksema, T.
Bibcode: 1992AAS...180.0606T
Altcode: 1992BAAS...24Q.737T
  No abstract at ADS

Title: Optical Components of the Solar Oscillations Imager-Michelson
    Doppler Imager
Authors: Tarbell, T.; Rosenberg, W.; Pope, T.; Huff, L.; Torgerson,
   D.; Title, A.; Wolfson, J.; Scherrer, P.; Bush, R.; Hoeksema, T.
Bibcode: 1992AAS...180.0607T
Altcode: 1992BAAS...24R.737T
  No abstract at ADS

Title: High resolution observations: the state of the art and beyond.
Authors: Title, A.; Tarbell, T.; Shine, R.; Topka, K.; Frank, Z.
Bibcode: 1992ESASP.344....9T
Altcode: 1992spai.rept....9T
  Excellent telescopes on excellent sites with fast digital CCD cameras
  and special purpose computers allow the collection of broad band images
  at just the instants of good seeing. This has resulted in nearly optimal
  movies of the solar surface for several hours. When longer exposures
  are required for narrowband filtergrams or spectra it is not enough to
  capture single images. However, big fast memories allow the collection
  of many selected low signal-to-noise ratio images in real time, which
  can be summed to achieve the desired signal to noise ratios. Adaptive
  optics shows promise of diffraction limited images for limited fields
  of view. Nevertheless, groundbased observations will always be limited
  in their duration, uniformity, and resolution qualities which are
  essential for understanding the development and evolution of small scale
  processes. Until there are observations in space we will not be able
  to completely understand either the processes in the solar atmosphere
  or how processes occurring at different height are interrelated.

Title: SOI-MDI Onboard Real Time Data Reduction - Requirements
    and Design.
Authors: Milford, P.; Lindgren, R.; Tarbell, T.; Bacon, L.; Scherrer,
   P.
Bibcode: 1992AAS...180.0608M
Altcode: 1992BAAS...24..737M
  SOI-MDI is a space-based high-resolution helioseismology experiment. To
  observe Solar oscillations accurately requires a long time base of
  (nearly) continuous observations. Due to telemetry restrictions,
  SOI-MDI must carry out onboard data reduction of the high-resolution
  observations prior to sending the data to the ground. This paper
  summarizes the reduction requirements and discusses the hardware and
  software design of the processor built to meet these requirements. The
  main computational requirement to be met is the one-minute observing
  cadence, required to observe a solar signal with a Nyquist frequency
  corresponding to a 2-minute period. The analysis requires computing
  dopplergrams from the observed filtergrams and a partial spherical
  harmonic decomposition of the full disk dopplergrams. A custom image
  processor was designed to meet these specifications. Other requirements
  include low power, radiation tolerance and light weight. A design based
  on an ASIC, designed around the 2903 bitslice family of processors,
  has been developed to meet these requirements. The CPU includes three
  memory busses with simultaneous DMA transfers to main memory and a
  one-cycle 16 bit multiplier. Simultaneous access to the main memory by
  the CCD Camera, via a DMA memory adder (also implemented as an ASIC),
  and by the telemetry subsystem give the system sufficient performance
  to handle the 30 Mb/minute of input data. This work was supported by
  NASA Contract NAS5-30386 and Stanford Contract PR-6209.

Title: Investigation of solar active regions at high resolution
    by balloon flights of the solar optical universal polarimeter,
    definition phase
Authors: Tarbell, Theodore D.; Topka, Kenneth P.
Bibcode: 1992lock.reptQ....T
Altcode:
  The definition phase of a scientific study of active regions on the sun
  by balloon flight of a former Spacelab instrument, the Solar Optical
  Universal Polarimeter (SOUP) is described. SOUP is an optical telescope
  with image stabilization, tunable filter and various cameras. After
  the flight phase of the program was cancelled due to budgetary
  problems, scientific and engineering studies relevant to future balloon
  experiments of this type were completed. High resolution observations
  of the sun were obtained using SOUP components at the Swedish Solar
  Observatory in the Canary Islands. These were analyzed and published
  in studies of solar magnetic fields and active regions. In addition,
  testing of low-voltage piezoelectric transducers was performed,
  which showed they were appropriate for use in image stabilization on
  a balloon.

Title: Patterns in the photospheric magnetic field and percolation
    theory
Authors: Schrijver, C. J.; Zwaan, C.; Balke, A. C.; Tarbell, T. D.;
   Lawrence, J. K.
Bibcode: 1992A&A...253L...1S
Altcode:
  The magnetic field in solar plages forms a highly structured pattern
  with no apparent characteristic length scale. This pattern appears
  to be a fractal with a dimension between 1.45 and 1.60. Small-scale
  displacements of concentrations of magnetic flux in the network
  are consistent with a random walk on a fractal with a similar
  dimension. Percolation theory offers an effective explanation for
  observed geometric properties of small-scale flux concentrations
  in the solar photosphere, by demonstrating the close correspondence
  with clusters formed by randomly placed tracers on a 2D (irregular)
  lattice. Percolation theory also offers a model for the subdiffusive
  behavior of tracers performing a random walk on clusters formed
  by bonded sites. The geometry of flux concentrations and of the
  displacement of magnetic flux as a function of time are equivalent
  to situations in percolation theory below a critical value, called
  'the percolation threshold'.

Title: Observations of high frequency and high wavenumber solar
    oscillations
Authors: Fernandes, D. N.; Scherrer, P. H.; Tarbell, T. D.; Title,
   A. M.
Bibcode: 1992STIN...9232488F
Altcode:
  Doppler shift measurements of the Na D<SUB>1</SUB> absorption line
  have revealed solar oscillations in a new regime of frequency and
  wavenumber. Oscillations of vertical velocities in the temperature
  minimum and low chromosphere of the Sun are observed with frequencies
  ranging up to 9.5 mHz. The fundamental modes appear with wavenumbers
  up to 5.33 M/m (equivalent spherical harmonic degree, 3710). We find
  no evidence for chromospheric modes of a 3-minute period.

Title: High Resolution Observations of the Magnetic and Velocity
    Field of Simple Sunspots
Authors: Title, Alan M.; Frank, Zoe A.; Shine, Richard A.; Tarbell,
   T. D.; Topka, K. P.; Scharmer, Goran; Schmidt, Wolfgang
Bibcode: 1992ASIC..375..195T
Altcode: 1992sto..work..195T
  We have observed the disk passage of relatively simple round sunspots
  using a narrowband filter and a large format CCD detector and have
  created magnetograms, Dopplergrams, and continuum images nearly
  simultaneously. In addition the spectral resolution of the filter
  allows the construction of 'spectra' for all points in the field of
  view. The mean inclination of the magnetic field increases from 45-50
  deg to 70-75 deg across the penumbra and there is a fluctuation of the
  inclination angle about the mean of about 4 +/- 18 deg. The variation in
  inclination is large enough that substantial amounts of magnetic field
  are parallel to the solar surface from the mid to outer penumbra. The
  Evershed flow tends to occur in the regions where the magnetic field
  is horizontal. This suggests that the Evershed flow is confined to the
  regions of horizontal fields. We show that a simple sunspot model with
  azimuthal variations in inclination but no azimuthal variations of
  field strength is free from azimuthal Lorentz forces. The meridional
  component of the currents which arise from the azimuthal variation
  in inclination are parallel to the field lines. This suggests that a
  cylindrically symmetric magnetostatic sunspot model can be perturbed
  into one with azimuthal variations in inclination with some adjustment
  in the meridional force balance.

Title: Fractals in Magnetograms
Authors: Schrijver, C. J.; Zwaan, C.; Balke, A. C.; Tarbell, T. D.;
   Lawrence, J. K.
Bibcode: 1992ASPC...27...67S
Altcode: 1992socy.work...67S
  No abstract at ADS

Title: On the magnetic field of a sunspot penumbra.
Authors: Balthasar, H.; Schmidt, W.; Hofmann, A.; Tarbell, T. D.;
   Frank, Z. A.
Bibcode: 1992AGAb....7..153B
Altcode:
  No abstract at ADS

Title: Results from a Recent Observing Run with the Lockheed Solar
    Adaptive Optics System
Authors: Acton, D. S.; Tarbell, T. D.; Dunn, R. B.
Bibcode: 1991BAAS...23.1453A
Altcode:
  No abstract at ADS

Title: Low-Cost Space Missions in Solar Physics or Astrophysics
    Using Mass-Produced Spacecraft
Authors: Tarbell, T. D.; Jurcevich, B. K.; Title, A. M.; Topka, K. P.
Bibcode: 1991BAAS...23.1317T
Altcode:
  No abstract at ADS

Title: Properties of the Smallest Magnetic Elements on the Sun
Authors: Topka, K. P.; Smith, K. L.; Tarbell, T. D.; Title, A. M.;
   Scharmer, G.
Bibcode: 1991BAAS...23.1388T
Altcode:
  No abstract at ADS

Title: Power Spectra of Flows and Magnetic Fields in the Solar
    Photosphere
Authors: Tarbell, T. D.; Slater, G. L.; Frank, Z. A.; Topka, K. P.;
   Scharmer, G.; Schmidt, W.
Bibcode: 1991BAAS...23.1048T
Altcode:
  No abstract at ADS

Title: Field Geometry of Sunspots Inferred from Inclination Effects
Authors: Title, A. M.; Frank, Z. A.; Shine, R. A.; Tarbell, T. D.
Bibcode: 1991BAAS...23R1052T
Altcode:
  No abstract at ADS

Title: Sunspot Umbral and Penumbral Oscillations in Hα
Authors: Shine, R.; Tarbell, T.; Title, A.; Topka, K.; Frank, Z.;
   Smith, K.
Bibcode: 1991BAAS...23.1033S
Altcode:
  No abstract at ADS

Title: 1024 x 1024 CCD Cameras under Development and Operation at
    Lockheed PARL
Authors: Zayer, I.; Duncan, D.; Edwards, C.; Kelly, G.; Levay, M.;
   Morrill, M.; Title, A.; Tarbell, T.; Wolfson, J.; Rosenberg, W.
Bibcode: 1991BAAS...23.1056Z
Altcode:
  No abstract at ADS

Title: Stokes Polarimetry of a Sunspot from the Swedish Solar
    Observatory at La Palma
Authors: Topka, K. P.; Frank, Z. A.; Tarbell, T. D.; Title, A. M.;
   Scharmer, G.
Bibcode: 1991BAAS...23Q1052T
Altcode:
  No abstract at ADS

Title: Fractal Flux Tubes of the Solar Magnetic Field
Authors: Ruzmaikin, Alexander; Sokoloff, Dmitry; Tarbell, Theodore
Bibcode: 1991LNP...380..140R
Altcode: 1991IAUCo.130..140R; 1991sacs.coll..140R
  The small-scale solar magnetic field exceeding a given threshold forms
  a fractal set. A dimension of this fractal is found from magnetograms
  with varying linear resolution. The dimension depends on the value
  of the threshold magnetic field (multifractality). A simple dynamo
  model explaining the origin of the fractal magnetic structure is
  considered. The dynamo produces a magnetic field in the form of
  flux tubes with a fractal distribution of magnetic field across the
  tube. The observed dimension gives a possibility of estimating a degree
  of structuredness of the solar velocity field.

Title: Variation of granulation properties on a mesogranular scale
Authors: Brandt, P. N.; Ferguson, S.; Shine, R. A.; Tarbell, T. D.;
   Scharmer, G. B.
Bibcode: 1991A&A...241..219B
Altcode:
  A 79 min series of CCD images of the solar granulation with subarcsec
  spatial resolution is analyzed. Local correlation techniques are applied
  to determine horizontal displacements of the granular intensity pattern
  in a 14.2 by 12.2 sq arcsec field of view. The divergence of the average
  horizontal flow field shows mean cell sizes of 5 to 7 arcsec. Granules
  are selected with respect to area, brightness, lifetime, and expansion
  rate. It is shown that small, faint, short-lived, and fast collapsing
  granules are located preferentially in the negative divergence
  (down-draft) regions of the mesogranular flow field, while bright,
  long-lived, and rapidly expanding granules populate preferentially
  the positive divergence (up-draft) regions. The differences in area
  coverage range between + or - 6 percent and + or - 9 percent.

Title: Results from high resolution solar images and spectra obtained
    at the Pic du Midi Observatory (1986-1990)
Authors: Roudier, Th.; Muller, R.; Vigneau, J.; Auffret, H.; Espagnet,
   O.; Simon, G. W.; Title, A. M.; Frank, Z.; Shine, R. A.; Tarbell,
   T. D.; Mein, P.; Malherbe, J. M.
Bibcode: 1991AdSpR..11e.205R
Altcode: 1991AdSpR..11..205R
  We present an overview of our recent results about solar granulation and
  mesogranulation, obtained with Pic du Midi observations. These results
  were obtained during 1986-1990 using image and spectrographic analysis
  of high spatial resolution data. The study of the solar granulation,
  with 2 Dim. ``Multichannel Subtractive Double Pass'' (M.S.D.P.) spectra,
  shows a clear change of the dynamical regime at 3'' (⋍ 2200 km)
  of the photospheric velocity field when oscillatory components are
  filtered out. <P />A three hour movie obtained on film at Pic du Midi
  Observatory and analyzed at the Lockheed Research Laboratory and the
  National Solar Observatory (Sacramento Peak) was used to calculate
  the horizontal flow pattern. The mean lifetime of the diverging areas
  related to mesogranulation is estimated at 3 hours; these diverging
  areas are swept by the supergranulation flow towards the supergranule
  boundary with a mean speed of 0.4 km/s.

Title: Generation of Electric Currents and Waves on Magnetic Flux
    Tubes by Horizontal Velocities in the Photosphere (With 1 Figure)
Authors: Tarbell, T. D.; Slater, G. L.; Frank, Z. A.; Shine, R. A.;
   Topka, K. P.
Bibcode: 1991mcch.conf...39T
Altcode:
  No abstract at ADS

Title: SOUP Observations of Solar Activity
Authors: Shine, R. A.; Scharmer, G.; Tarbell, T. D.; Title, A. M.;
   Topka, K. P.
Bibcode: 1991max..conf..295S
Altcode:
  No abstract at ADS

Title: Solar magnetic field strength determinations from high spatial
    resolution filtergrams
Authors: Keller, C. U.; Stenflo, J. O.; Solanki, S. K.; Tarbell,
   T. D.; Title, A. M.
Bibcode: 1990A&A...236..250K
Altcode:
  Circularly polarized images with high spatial resolution (better than 1
  arcsec) of a solar active region, obtained with a tunable filter in the
  wings of Fe I 5247.1 A and Fe I 5250.2 A, have been analyzed in terms of
  the magnetic line ratio technique introduced by Stenflo (1973). Whenever
  a measurable amount of polarization is present, the distribution of
  the observed magnetic-line ratio is compatible with a unique value,
  which is randomly blurred by noise due to the photon statistics,
  the CCD camera, and atmospheric distortions. There is no need for a
  distribution of field strengths to explain the observed distribution of
  the magnetic line ratio. Consequently, the observations are compatible
  with a unique magnetic field strength in solar small-scale magnetic
  elements of about 1000 G at the level of line formation. For a thin
  flux tube, this corresponds to a field strength of approximately 2000
  G at the level of continuum formation, which is in excellent agreement
  with previous field strength determinations from low spatial resolution
  spectra (4-10 arcsec).

Title: Detailed Comparison of Quiet and Magnetic Sun
Authors: Topka, K.; Ferguson, S.; Shine, R.; Tarbell, T.; Title, A.;
   Balke, C.; Scharmer, G.; Schmidt, W.
Bibcode: 1990BAAS...22R.879T
Altcode:
  No abstract at ADS

Title: Penumbral Flows and Magnetic Fields
Authors: Shine, R.; Smith, K.; Tarbell, T.; Title, A.; Scharmer, G.
Bibcode: 1990BAAS...22..878S
Altcode:
  No abstract at ADS

Title: Intermittency of Fine Scale Solar Magnetic Fields in the
    Photosphere
Authors: Tarbell, T.; Acton, S.; Topka, K.; Title, A.; Schmidt, W.;
   Scharmer, G.
Bibcode: 1990BAAS...22..878T
Altcode:
  No abstract at ADS

Title: Generation of Waves and Electric Currents on Magnetic Flux
    Tubes by Horizontal and Vertical Velocities in the Photosphere
Authors: Frank, Z. A.; Shine, R. A.; Slater, G.; Tarbell, T.; Topka, K.
Bibcode: 1990BAAS...22..878F
Altcode:
  No abstract at ADS

Title: Magnetic flux tubes and their relation to continuum and
    photospheric features
Authors: Title, A.; Tarbell, T.; Topka, K.; Cauffman, D.; Balke, C.;
   Scharmer, G.
Bibcode: 1990GMS....58..171T
Altcode:
  An investigation is made of the relationship between photospheric
  'filigree' light points, line-center brightness, and magnetic field,
  as inferred from sets of individual images and films showing a distinct
  difference between two classes of magnetic regions. While in the first
  such region the vertical velocity field is average and the magnetic
  field is mostly confined in narrow lanes, the granulation pattern
  of the second scale is much smaller, the vertical velocity is lower,
  and the magnetic field is less compact. Where granulation is normal,
  excellent correlation is obtained between bright continuum, line-center,
  and magnetic field line structure.

Title: High-Resolution Observations of Emerging Magnetic Fields and
    Flux Tubes in Active Region Photosphere
Authors: Tarbell, T.; Ferguson, S.; Frank, Z.; Shine, R.; Title, A.;
   Topka, K.; Scharmer, G.
Bibcode: 1990IAUS..138..147T
Altcode:
  No abstract at ADS

Title: Structure and Evolution of the Large Scale Granulation
Authors: Muller, R.; Roudier, Th.; Vigneau, J.; Frank, Z.; Shine,
   R.; Tarbell, T.; Title, A.; Simon, G.
Bibcode: 1990PDHO....7...44M
Altcode: 1990dysu.conf...44M; 1990ESPM....6...44M
  A granulation movie of 3 hours has been performed at the Pic du Midi
  Observatory on September 20, 1988.

Title: High Resolution Observations of the Photosphere
Authors: Title, A. M.; Shine, R. A.; Tarbell, T. D.; Topka, K. P.;
   Scharmer, G. B.
Bibcode: 1990IAUS..138...49T
Altcode:
  No abstract at ADS

Title: Formation of Network Bright Points by Granule Compression
Authors: Muller, R.; Roudier, Th.; Vigneau, J.; Frank, Z.; Shine,
   R.; Tarbell, T.; Title, A.; Simon, G.
Bibcode: 1990PDHO....7..150M
Altcode: 1990dysu.conf..150M; 1990ESPM....6..150M
  No abstract at ADS

Title: Intial Results of the Lockheed 1989 La Palma Observing Campaign
Authors: Topka, K.; Frank, Z.; Shine, R.; Smith, K.; Tarbell, T.;
   Title, A.; Scharmer, G.
Bibcode: 1989BAAS...21.1111T
Altcode:
  No abstract at ADS

Title: High - resolution observations of emerging magnetic flux
Authors: Tarbell, T. D.; Topka, K.; Ferguson, S.; Frank, Z.; Title,
   A. M.
Bibcode: 1989hsrs.conf..506T
Altcode:
  No abstract at ADS

Title: Variation of granulation properties on a meso-granular scale
Authors: Brandt, P. N.; Ferguson, S.; Scharmer, G. B.; Shine, R. A.;
   Tarbell, T. D.; Title, A. M.; Topka, K.
Bibcode: 1989hsrs.conf..473B
Altcode:
  No abstract at ADS

Title: Proper Motion and Lifetime of Mesogranules
Authors: Frank, Z.; Muller, R.; Roudier, T.; Vigneau, J.; Shine, R.;
   Tarbell, T.; Title, A.; Topka, K.; Simon, G.
Bibcode: 1989BAAS...21..841F
Altcode:
  No abstract at ADS

Title: Short Term Evolution of Fine Scale Magnetic Structures
Authors: Topka, K.; Frank, Z.; Shine, R.; Tarbell, T.; Title, A.;
   Scharmer, G.; Balke, A.
Bibcode: 1989BAAS...21..842T
Altcode:
  No abstract at ADS

Title: Magnetic Field Inclination in Penumbra of a Round Sunspot
    Observed at Very High Spatial Resolution
Authors: Title, A. M.; Frank, Z. A.; Shine, R. A.; Tarbell, T. D.;
   Scharmer, G.
Bibcode: 1989BAAS...21Q.837T
Altcode:
  No abstract at ADS

Title: Investigation of Active Regions at High Resolution by Balloon
    Flights of the Solar Optical Universal Polarimeter (SOUP)
Authors: Tarbell, T.; Gilbreth, C.; Shine, R.; Title, A.; Topka, K.;
   Wolfson, J.
Bibcode: 1989BAAS...21R.837T
Altcode:
  No abstract at ADS

Title: Observations of Running Penumbral Waves
Authors: Shine, R.; Tarbell, T.; Title, A.; Topka, K.; Frank, Z.;
   Scharmer, G.
Bibcode: 1989BAAS...21..837S
Altcode:
  No abstract at ADS

Title: Generation of Waves on Magnetic Flux Tubes by Horizontal
    Velocities in the Photosphere
Authors: Tarbell, T. D.; Ferguson, S. H.; Frank, Z. A.; Shine, R. A.
Bibcode: 1989BAAS...21..830T
Altcode:
  No abstract at ADS

Title: Ground-Based Tunable Filter Observations
Authors: Title, A. M.; Tarbell, T. D.; Wolfson, C. J.
Bibcode: 1989ASIC..263...25T
Altcode: 1989ssg..conf...25T
  No abstract at ADS

Title: Details of Large Scale Solar Motions Revealed by Granulation
    Test Particles
Authors: Simon, G. W.; November, L. J.; Ferguson, S. H.; Shine, R. A.;
   Tarbell, T. D.; Title, A. M.; Topka, K. P.; Zirin, H.
Bibcode: 1989ASIC..263..371S
Altcode: 1989ssg..conf..371S
  No abstract at ADS

Title: Statistical Properties of Solar Granulation Derived from the
    SOUP Instrument on Spacelab 2
Authors: Title, A. M.; Tarbell, T. D.; Topka, K. P.; Ferguson, S. H.;
   Shine, R. A.; SOUP Team
Bibcode: 1989ApJ...336..475T
Altcode:
  Computer algorithms and statistical techniques were used to identify,
  measure, and quantify the properties of solar granulation derived
  from movies collected by the Solar Optical Universal Polarimeter on
  Spacelab 2. The results show that there is neither a typical solar
  granule nor a typical granule evolution. A granule's evolution is
  dependent on local magnetic flux density, its position with respect to
  the active region plage, its position in the mesogranulation pattern,
  and the evolution of granules in its immediate neighborhood.

Title: Optical disk processing of solar images.
Authors: Title, A.; Tarbell, T.
Bibcode: 1989GMS....54...31T
Altcode: 1989sspp.conf...31T
  The current generation of space and ground-based experiments in solar
  physics produces many megabyte-sized image data arrays. Optical
  disk technology is the leading candidate for convenient analysis,
  distribution, and archiving of these data. The authors have been
  developing data analysis procedures which use both analog and digital
  optical disks for the study of solar phenomena.

Title: Flows, Random Motions and Oscillations in Solar Granulation
    Derived from the SOUP Instrument on Spacelab 2
Authors: Title, A. M.; Tarbell, T. D.; Topka, K. P.; Ferguson, S. H.;
   Shine, R. A.; SOUP Team
Bibcode: 1989ASIC..263..225T
Altcode: 1989ssg..conf..225T
  No abstract at ADS

Title: Magnetoconvection on the solar surface.
Authors: Simon, G. W.; Title, A. M.; Topka, K. P.; Tarbell, T. D.;
   Shine, R. A.; Ferguson, S. H.; Zirin, H.
Bibcode: 1989GMS....54...53S
Altcode: 1989sspp.conf...53S
  The authors describe and illustrate the first high-resolution
  observations of horizontal flows on the solar surface and their relation
  to magnetic field structure seen in the Sun's photosphere.

Title: Vortex Motion of the Solar Granulation
Authors: Brandt, P. N.; Scharmer, G. B.; Ferguson, S. H.; Shine,
   R. A.; Tarbell, T. D.; Title, A. M.
Bibcode: 1989ASIC..263..305B
Altcode: 1989ssg..conf..305B
  No abstract at ADS

Title: Investigation of active regions at high resolution by balloon
    flights of the Solar Optical Universal Polarimeter (SOUP)
Authors: Tarbell, T.; Frank, Z.; Gilbreth, C.; Shine, R.; Title, A.;
   Topka, K.; Wolfson, J.
Bibcode: 1989dots.work..310T
Altcode:
  SOUP is a versatile, visible-light solar observatory, built for space
  or balloon flight. It is designed to study magnetic and velocity
  fields in the solar atmosphere with high spatial resolution and
  temporal uniformity, which cannot be achieved from the surface of the
  earth. The SOUP investigation is carried out by the Lockheed Palo Alto
  Research Laboratory, under contract to NASA's Marshall Space Flight
  Center. Co-investigators include staff members at a dozen observatories
  and universities in the U.S. and Europe. The primary objectives of the
  SOUP experiment are: to measure vector magnetic and velocity fields in
  the solar atmosphere with much better spatial resolution than can be
  achieved from the ground; to study the physical processes that store
  magnetic energy in active regions and the conditions that trigger
  its release; and to understand how magnetic flux emerges, evolves,
  combines, and disappears on spatial scales of 400 to 100,000 km. SOUP
  is designed to study intensity, magnetic, and velocity fields in the
  photosphere and low chromosphere with 0.5 arcsec resolution, free of
  atmospheric disturbances. The instrument includes: a 30 cm Cassegrain
  telescope; an active mirror for image stabilization; broadband film
  and TV cameras; a birefringent filter, tunable over 5100 to 6600 A
  with 0.05 A bandpass; a 35 mm film camera and a digital CCD camera
  behind the filter; and a high-speed digital image processor.

Title: The Michelson Doppler imager for the solar oscillations imager
    program on SOHO.
Authors: Hoeksema, J. T.; Scherrer, Philip H.; Title, A. M.; Tarbell,
   T. D.
Bibcode: 1988ESASP.286..407H
Altcode: 1988ssls.rept..407H
  The Michelson Doppler Imager (MDI) will be the instrument used
  in the Solar Oscillations Imager Program on SOHO. MDI will make a
  line-of-sight velocity map of the full solar disk with 2 arc-second
  pixels each minute. The instrument will be a modification of the
  Fourier Tachometer and will operate by using narrow bandpass solar
  images at four wavelengths to measure the line profile of the Ni
  I line at 6768 Å. This method is relatively insensitive to line
  profile changes and has a linear response to velocity. The instrument
  is also capable of making partial maps with 0.7 arc-sec pixels. All
  data will be transmitted to the ground for two continuous months
  each year and 8 hours each day (160 kilobits/sec). At all times the
  on-board computer will compute and transmit a selection of modes
  (5 kilobits/sec) to take full advantage of the advantages of a space
  based telescope. Line-of-sight magnetic fields will also be measured
  regularly. The flight instrument will be built by the Lockheed Palo
  Alto Research Laboratory.

Title: Observations of f- and p-mode oscillations of high degree
    (500 &lt; l &lt; 2500) in quiet and active Sun.
Authors: Tarbell, T. D.; Peri, M.; Frank, Z.; Shine, R.; Title, A. M.
Bibcode: 1988ESASP.286..315T
Altcode: 1988ssls.rept..315T
  Spectra (l-ν diagrams) from high resolution observations taken at
  the Vacuum Tower Telescope (NSO/Sunspot) are presented. The raw data
  are CCD images taken through the SOUP narrowband filter in Fe I 5576
  Å. Four filtergrams spaced through the spectral line are combined to
  form velocity movies. Spectra for 80 minutes of data with 0.5 - 1.5
  arcsecond resolution are presented for the entire field-of-view and
  for quiet and magnetic (plage) subregions. Ridges f and p<SUB>1</SUB> -
  p<SUB>5</SUB> are evident in velocity spectra, extending to l = 2500(f),
  l = 1800(p<SUB>1</SUB>), and l = 1200(p<SUB>2</SUB>). Much less power is
  seen in the magnetic region than in the quiet sun. Three-dimensional
  Fourier filtering shows that oscillation velocity amplitude drops
  sharply at the boundary of the active region for each family of modes
  considered.

Title: SOI: The Solar Oscillations Imager on SOHO
Authors: Scherrer, P. H.; Hoeksema, J. T.; Bogart, R. S.; Walker,
   A. B. C., Jr.; Title, A. M.; Tarbell, T. D.; Wolfson, C. J.; Brown,
   T. M., Jr.; Christensen-Dalsgaard, J.; Gough, D. O.
Bibcode: 1988sohi.rept...25S
Altcode:
  The Solar Oscillations Imager (SOI) program for SOHO (solar and
  heliospheric observatory) is described. It will consist of a Michelson
  Doppler Imager (MDI) instrument, a facility providing data reduction
  and analysis capability, and a coordinated set of investigations
  designed to address a set of science objectives. The MDI is designed
  to take advantage of the anticipated SOHO telemetry by organizing
  the observations into four observation programs: structure (at all
  times), dynamics (two months per year), campaign (eight hours per day,
  ten months per year), and magnetic fields (few minutes per day). The
  MDI will measure line-of-sight velocity by Doppler shift, transverse
  velocity by local correlation tracking, line and continuum intensity,
  and line-of-sight magnetic fields with both 4 and 1.4 arc-second
  resolution (2 and 0.7 arc-sec pixels respectively).

Title: High-resolution digital movies of emerging flux and horizontal
    flows in active regions on the sun
Authors: Topka, K.; Ferguson, S.; Frank, Z.; Tarbell, T.; Title, A.
Bibcode: 1988fnsm.work..283T
Altcode:
  High-resolution observations of active regions in many wavelength bands
  obtained at the Vacuum Tower Telescope of NSO/Sunspot (Sacramento Peak)
  are presented. The SOUP tunable filter, HRSO 1024 x 1024 CCD camera,
  and a sunspot tracker for image stabilization were used. Subarrays of
  512 x 512 pixels were processed digitally and recorded on videodisk
  in movie format. The movies with 0.5 to 1 arcsecond resolution of
  the following simultaneous observations were shown: green continuum,
  longitudinal magnetogram, Doppler velocity, Fe I 5576 A line center,
  H alpha wings, and H alpha line center. The best set of movies show a
  90 x 90 arcsecond field-of-view of an active region at S29, W11. When
  viewed at speeds of a few thousand times real-time, the photospheric
  movies clearly show the active region fields being distorted by a
  remarkable combination of systematic flows and small eruptions of new
  flux. Flux emergence is most easily discovered in line center movies:
  an elongated dark feature appears first, followed soon after by bright
  points at one or both ends. A brief, strong upflow is seen when the
  dark feature first appears; downflow in the bright points persists
  much longer. The magnetic flux appears to increase gradually over this
  extended period. Some of the flux emergence events were studied in
  detail, with measurements of horizontal and vertical velocities and
  magnetic flux versus time within one footpoint of the loop.

Title: Statistical properties of solar granulation from the SOUP
    instrument on Spacelab 2
Authors: Topka, K.; Title, A.; Tarbell, T.; Ferguson, S.; Shine, R.
Bibcode: 1988fnsm.work..294T
Altcode:
  The Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 collected
  movies of solar granulation completely free from atmospheric blurring,
  and are not degraded by pointint jitter (the pointing stability
  was 0.003 sec root mean square). The movies illustrate that the
  solar five minute oscillation has a major role in the appearance of
  solar granulation and that exploding granules are a common feature
  of the granule evolution. Using 3-D Fourier filtering techniques
  the oscillations were removed and it was demonstrated that the
  autocorrelation lifetime of granulation is a factor of two greater
  in magnetic field regions than in field-free quiet sun. Horizontal
  velocities were measured and flow patterns were observed on the scale of
  meso- and super granulation. In quiet regions the mean flow velocity
  is 370 m/s while in the magnetic regions it is about 125 m/s. It
  was also found that the root mean square (RMS) fluctuating horizonal
  velocity field is substantially greater in quiet sun than in strong
  magnetic field regions. By superimposing the location of exploding
  granules on the average flow maps it was found that they appear almost
  exclusively in the center of mesogranulation size flow cells. Because
  of the nonuniformity of the distribution of exploding granules, the
  evolution of the granulation pattern in mesogranule cell centers and
  boundaries differs fundamentally. It is clear from this study there
  is neither a typical granule nor a typical granule evolution.

Title: Observations of photospheric magnetic fields and shear flows
    in flaring active regions
Authors: Tarbell, T.; Ferguson, S.; Frank, Z.; Title, A.; Topka, K.
Bibcode: 1988fnsm.work...50T
Altcode:
  Horizontal flows in the photosphere and subsurface convection zone move
  the footpoints of coronal magnetic field lines. Magnetic energy to power
  flares can be stored in the corona if the flows drive the fields far
  from the potential configuration. Videodisk movies were shown with 0.5
  to 1 arcsecond resolution of the following simultaneous observations:
  green continuum, longitudinal magnetogram, Fe I 5576 A line center
  (mid-photosphere), H alpha wings, and H alpha line center. The movies
  show a 90 x 90 arcsecond field of view of an active region at S29,
  W11. When viewed at speeds of a few thousand times real-time, the
  photospheric movies clearly show the active region fields being
  distorted by a remarkable combination of systematic flows and small
  eruptions of new flux. Magnetic bipoles are emerging over a large area,
  and the polarities are systematically flowing apart. The horizontal
  flows were mapped in detail from the continuum movies, and these may
  be used to predict the future evolution of the region. The horizontal
  flows are not discernable in H alpha. The H alpha movies strongly
  suggest reconnection processes in the fibrils joining opposite
  polarities. When viewed in combination with the magnetic movies,
  the cause for this evolution is apparent: opposite polarity fields
  collide and partially cancel, and the fibrils reconnect above the
  surface. This type of reconnection, driven by subphotospheric flows,
  complicates the chromospheric and coronal fields, causing visible
  braiding and twisting of the fibrils. Some of the transient emission
  events in the fibrils and adjacent plage may also be related.

Title: Fractal Geometry of Convective Flows and Magnetic Fields in
    the Solar Atmosphere
Authors: Tarbell, T.; Ferguson, S.; Title, A.; Scharmer, G.; Brandt, P.
Bibcode: 1988BAAS...20Q1010T
Altcode:
  No abstract at ADS

Title: Observations of Granulation in Quiet and Magnetic Sun from
    the Swedish Solar Observatory on LaPalma
Authors: Topka, K.; Ferguson, S.; Frank, Z.; Shine, R.; Tarbell, T.;
   Title, A.; Wolfson, J.; Scharmer, G.; Brandt, P.
Bibcode: 1988BAAS...20S1010T
Altcode:
  No abstract at ADS

Title: On the Feasibility of Correlation Tracking at Moderate
    Resolution
Authors: Bogart, R. S.; Ferguson, S. H.; Scherrer, P. H.; Tarbell,
   T. D.; Title, A. M.
Bibcode: 1988SoPh..116..205B
Altcode:
  The SOUP experiment demonstrated that photospheric surface flows can
  be measured by correlation tracking of white-light intensity features
  at high resolution (November et al., 1987). In order to assess
  the feasibility of this technique with observations made at lower
  resolution, we have applied it to the same SOUP data artificially
  degraded, but still free of seeing distortion. Comparison with the
  velocity structures inferred from the original data shows generally
  good agreement when the resolution is better than about 2″. The
  radial outflow from a sunspot penumbra, however, can only be seen with
  resolution of better than 1″. With resolution of worse than 2″,
  the inferred velocity fields rapidly lose coherence, while resolution of
  better than 1″ yields little improvement. We conclude that apertures
  as small as 10-14 cm on a space-based platform will be useful for the
  measurement of large-scale horizontal motions.

Title: Solar Activity and Flare Observations from the Swedish Solar
    Observatory on La Palma
Authors: Wolfson, J.; Ferguson, S.; Frank, Z.; Shine, R.; Tarbell,
   T.; Title, A.; Topka, K.; Scharmer, G.; Brandt, P.; Gurman, J.
Bibcode: 1988BAAS...20..978W
Altcode:
  No abstract at ADS

Title: Measurements of Turbulent Diffusion by Solar Granulation in
    Quiet and Magnetic Areas
Authors: Title, A.; Ferguson, S.; Tarbell, T.; Scharmer, G.; Brandt, P.
Bibcode: 1988BAAS...20R1010T
Altcode:
  No abstract at ADS

Title: Vortex flow in the solar photosphere
Authors: Brandt, P. N.; Scharmer, G. B.; Ferguson, S.; Shine, R. A.;
   Tarbell, T. D.; Title, A. M.
Bibcode: 1988Natur.335..238B
Altcode:
  Convective flow fields in the solar atmosphere play a key role in the
  concentration and dispersal of magnetic flux<SUP>1</SUP>, but because
  the individual flow elements-the solar granules-are a few arcsec or less
  in size, studies of their motions have been limited by the distortion
  and blurring of the Earth's atmosphere ('seeing'). We report here a
  very high-quality series of granulation images taken at the new Swedish
  Solar Observatory on La Palma (Canary Islands) which have permitted
  flow measurements at the sub-arcsec level. These movies show a vortex
  structure which visibly dominates the motion of the granules in its
  neighbourhood and persists for the 1.5 h duration of the movie. If such
  vortices are a common feature of the solar convective zone, they may
  provide an important mechanism for the heating of stellar chromospheres
  and coronae by twisting the footprints of magnetic flux tubes.

Title: On the Relation between Photospheric Flow Fields and the
    Magnetic Field Distribution on the Solar Surface
Authors: Simon, George W.; Title, A. M.; Topka, K. P.; Tarbell, T. D.;
   Shine, R. A.; Ferguson, S. H.; Zirin, H.; SOUP Team
Bibcode: 1988ApJ...327..964S
Altcode:
  Using the technique of local correlation tracking on a 28 minute time
  sequence of white-light images of solar granulation, the horizontal
  flow field on the solar surface is measured. The time series was
  obtained by the Solar Optical Universal Polarimeter (SOUP) on Spacelab 2
  (Space Shuttle flight 51-F) and is free from atmospheric blurring and
  distortion. The SOUP flow fields have been compared with carefully
  aligned magnetograms taken over a nine hour period at the Big Bear
  Solar Observatory before, during, and after the SOUP images. The flow
  field and the magnetic field agree in considerable detail: vectors which
  define the flow of the white-light intensity pattern (granulation) point
  toward magnetic field regions, magnetic fields surround flow cells, and
  magnetic features move along the flow arrows. The projected locations
  of free particles ('corks') in the measured flow field congregate at
  the same locations where the magnetic field is observed.

Title: Observations of F-and P-Mode Oscillations of High Degree
    (500&lt; &lt;3500) in Quiet and Active Sun
Authors: Peri, M.; Frank, Z.; Shine, R.; Tarbell, T.; Title, A.
Bibcode: 1988BAAS...20..702P
Altcode:
  No abstract at ADS

Title: Convection and Magnetic Fields on the Sun
Authors: Tarbell, T.
Bibcode: 1988BAAS...20..723T
Altcode:
  No abstract at ADS

Title: A New Technique for Measuring Solar Velocity
Authors: Scherrer, P. H.; Tarbell, T. D.
Bibcode: 1988BAAS...20..702S
Altcode:
  No abstract at ADS

Title: Observations of Photospheric Magnetic Fields and Shear Flows
    in Flaring Active Regions
Authors: Tarbell, T.; Ferguson, S.; Frank, Z.; Title, A.; Topka, K.
Bibcode: 1988BAAS...20..744T
Altcode:
  No abstract at ADS

Title: High-Resolution Digital Movies of Emerging Flux and Horizontal
    Flows in Active Regions on the Sun
Authors: Tarbell, T.; Ferguson, S.; Frank, Z.; Title, A.; Topka, K.
Bibcode: 1988BAAS...20..680T
Altcode:
  No abstract at ADS

Title: Solar Granulation Movies of Exceptional Spatial Resolution:
    Observations and Simulations of Horizontal Convective Flows
Authors: Title, A.; Shine, R.; Ferguson, S.; Tarbell, T.; Brandt,
   P.; Scharmer, G.
Bibcode: 1988BAAS...20R.679T
Altcode:
  No abstract at ADS

Title: Statistical Properties of Solar Granulation from the SOUP
    Instrument on Spacelab 2
Authors: Topka, K.; Title, A.; Tarbell, T.; Ferguson, S.; Shine, R.
Bibcode: 1988BAAS...20Q.679T
Altcode:
  No abstract at ADS

Title: Variability of solar mesogranulation
Authors: Simon, G. W.; November, L. J.; Acton, L. W.; Ferguson, S. H.;
   Shine, R. A.; Tarbell, T. D.; Title, A. M.; Topka, K. P.; Zirin, H.
Bibcode: 1988AdSpR...8g.169S
Altcode: 1988AdSpR...8..169S
  From white-light photographs of solar granulation obtained with the
  SOUP instrument on Space Shuttle Flight STS-19 we have measured the
  motions of granules using local correlation tracking techniques. The
  granules are organized into larger-scale structures (mesogranular and
  supergranular) which exhibit outflow from upwellings, convergence into
  sinks, as well as significant vorticity. Magnetic fields follow these
  same flow patterns. We describe these velocity structures, and suggest
  that their effect on magnetic field structures may be important to
  the solar flare buildup process.

Title: Correlation Lifetimes of Quiet and Magnetic Granulation from
    the SOUP Instrument on Spacelab 2
Authors: Title, A.; Tarbell, T.; Topka, K.; Acton, L.; Duncan, D.;
   Ferguson, S.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren, R.; Morrill,
   M.; Pope, T.; Reeves, R.; Rehse, R.; Shine, R.; Simon, G.; Harvey,
   J.; Leibacher, J.; Livingston, W.; November, L.; Zirker, J.
Bibcode: 1988ApL&C..27..141T
Altcode:
  The time sequences of diffraction limited granulation images obtained by
  the Solar Optical Universal Polarimeter on Spacelab 2 are presented. The
  uncorrection autocorrelation limetime in magnetic regions is dominated
  by the 5-min oscillation. The removal of this oscillation causes the
  autocorrelation lifetime to increase by more than a factor of 2. The
  results suggest that a significant fraction of granule lifetimes are
  terminated by nearby explosions. Horizontal displacements and transverse
  velocities in the intensity field are measured. Lower limits to the
  lifetime in the quiet and magnetic sun are set at 440 s and 950 s,
  respectively.

Title: Max '91: Flare research at the next solar maximum
Authors: Dennis, Brian; Canfield, Richard; Bruner, Marilyn; Emslie,
   Gordon; Hildner, Ernest; Hudson, Hugh; Hurford, Gordon; Lin, Robert;
   Novick, Robert; Tarbell, Ted
Bibcode: 1988STIN...8814919D
Altcode:
  To address the central scientific questions surrounding solar
  flares, coordinated observations of electromagnetic radiation and
  energetic particles must be made from spacecraft, balloons, rockets,
  and ground-based observatories. A program to enhance capabilities
  in these areas in preparation for the next solar maximum in 1991 is
  recommended. The major scientific issues are described, and required
  observations and coordination of observations and analyses are
  detailed. A program plan and conceptual budgets are provided.

Title: The relation between convection flows and magnetic structure
    at the solar surface
Authors: Simon, G. W.; November, L. J.; Acton, L. W.; Title, A. M.;
   Tarbell, T. D.; Topka, K. P.; Shine, R. A.; Ferguson, S. H.; Weiss,
   N. O.; Zirin, H.
Bibcode: 1988AdSpR...8k.133S
Altcode: 1988AdSpR...8..133S
  We describe recent results from the comparison of data from the Solar
  Optical Universal Polarimeter instrument on Spacelab 2 and magnetograms
  from Big Bear Solar Observatory. We show that the Sun's surface velocity
  field governs the structure of the observed magnetic field over the
  entire solar surface outside sunspots and pores. We attempt to describe
  the observed flows by a simple axisymmetric plume model. Finally,
  we suggest that these observations may have important implications
  for the prediction of solar flares, mass ejections, and coronal heating.

Title: White Light Sunspot Observations from the Solar Optical
    Universal Polarimeter on Spacelab-2
Authors: Shine, R. A.; Title, A. M.; Tarbell, T. D.; Topka, K. P.
Bibcode: 1987Sci...238.1264S
Altcode:
  The flight of the Solar Optical Universal Polarimeter on Spacelab-2
  provided the opportunity for the collection of time sequences of
  diffraction-limited (0.5 arc second) solar images with excellent
  pointing stability (0.003 arc second) and with freedom from the
  distortion that plagues ground-based images. A series of white-light
  images of active region 4682 were obtained on 5 August 1985, and
  the area containing the sunspot has been analyzed. These data have
  been digitally processed to remove noise and to separate waves from
  low-velocity material motions. The results include (i) proper motion
  measurements of a radial outflow in the photospheric granulation
  pattern just outside the penumbra; (ii) discovery of occasional bright
  structures (``streakers'') that appear to be ejected outward from the
  penumbra; (iii) broad dark ``clouds'' moving outward in the penumbra,
  in addition to the well-known bright penumbral grains moving inward;
  (iv) apparent extensions and contractions of penumbral filaments over
  the photosphere; and (v) observation of a faint bubble or looplike
  structure that seems to expand from two bright penumbral filaments
  into the photosphere.

Title: High-Resolution CCD Observations of Doppler and Magnetic
    Images in the Solar Photosphere
Authors: Tarbell, T. D.; Frank, Z. A.; Morrill, M. E.; Shine, R. A.;
   Topka, K. P.; Title, A. M.
Bibcode: 1987BAAS...19.1117T
Altcode:
  No abstract at ADS

Title: Power Spectra of Solar Granulation
Authors: Acton, D. S.; Brandt, P.; Scharmer, G.; Dunn, D.; Tarbell,
   T. D.; Title, A. M.; Smithson, R. C.
Bibcode: 1987BAAS...19.1118A
Altcode:
  No abstract at ADS

Title: Sunspot observations from the SOUP instrument on Spacelab 2.
Authors: Shine, R. A.; Title, A. M.; Tarbell, T. D.; Acton, L.; Duncan,
   D.; Ferguson, S. H.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren, R.
Bibcode: 1987NASCP2483..133S
Altcode: 1987tphr.conf..133S
  A series of white light images obtained by the SOUP instrument on
  Spacelab 2 of active region 4682 on August 5, 1985 were analyzed
  in the area containing sunspots. Although the umbra of the spot is
  underexposed, the film is well exposed in the penumbral regions. These
  data were digitally processed to remove noise and to separate p-mode
  oscillations from low velocity material motions. The results of this
  preliminary investigation include: (1) proper motion measurements of
  a radial outflow in the photospheric granulation pattern just outside
  the penumbra; (2) discovery of occasional bright structures (streakers)
  that appear to be ejected outward from the penumbra; (3) broad dark
  clouds moving outward in the penumbra in addition to the well known
  bright penumbral grains moving inward; (4) apparent extensions and
  contractions of penumbral filaments over the photosphere; and (5)
  observation of a faint bubble or loop-like structure which seems to
  expand from two bright penumbral filaments into the photosphere.

Title: Large-scale horizontal flows from SOUP observations of solar
    granulation.
Authors: November, L. J.; Simon, G. W.; Tarbell, T. D.; Title, A. M.;
   Ferguson, S. H.
Bibcode: 1987NASCP2483..121N
Altcode: 1987tphr.conf..121N
  Using high-resolution time-sequence photographs of solar granulation
  from the SOUP experiment on Spacelab 2 the authors observed large-scale
  horizontal flows in the solar surface. The measurement method is
  based upon a local spatial cross correlation analysis. The horizontal
  motions have amplitudes in the range 300 to 1000 m/s. Radial outflow of
  granulation from a sunspot penumbra into the surrounding photosphere is
  a striking new discovery. Both the supergranulation pattern and cellular
  structures having the scale of mesogranulation are seen. The vertical
  flows that are inferred by continuity of mass from these observed
  horizontal flows have larger upflow amplitudes in cell centers than
  downflow amplitudes at cell boundaries.

Title: First results on quiet and magnetic granulation from SOUP.
Authors: Title, A. M.; Tarbell, T. D.; Acton, L.; Duncan, D.; Ferguson,
   S. H.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren, R.; Morrill, M.
Bibcode: 1987NASCP2483...55T
Altcode: 1987tphr.conf...55T
  The flight of Solar Optical Universal Polarimeter (SOUP) on Spacelab
  2 allowed the collection of time sequences of diffraction limited (0.5
  arc sec) granulation images with excellent pointing (0.003 arc sec) and
  completely free of the distortion that plagues groundbased images. The
  p-mode oscillations are clearly seen in the data. Using Fourier
  transforms in the temporal and spatial domain, it was shown that the
  p-modes dominate the autocorrelation lifetime in magnetic regions. When
  these oscillations are removed the autocorrelation lifetime is found
  to be 500 sec in quiet and 950 sec in magnetic regions. In quiet
  areas exploding granules are seen to be common. It is speculated that
  a significant fraction of granule lifetimes are terminated by nearby
  explosions. Using local correlation tracking techniques it was able to
  measure horizontal displacements, and thus transverse velocities, in
  the magnetic field. In quiet sun it is possible to detect both super
  and mesogranulation. Horizontal velocities are as great as 1000 m/s
  and the average velocity is 400 m/s. In magnetic regions horizontal
  velocities are much less, about 100 m/s.

Title: On the Relation between Magnetic Field Structures and
    Granulation
Authors: Title, A. M.; Tarbell, T. D.; Topka, K. P.
Bibcode: 1987ApJ...317..892T
Altcode:
  Narrow-band observations of a solar emerging-flux region, obtained
  at 525.02 nm with resolution 0.5 arcsec using the Sacramento Peak
  vacuum-tower telescope and the Spacelab 2 tunable filter on December
  10, 1979, are reported. The data are presented in histograms and
  characterized in detail. Magnetic-flux concentrations of 600-1000 G
  are found to be located in areas of suppressed downflow near holes or
  pores in the granulation pattern, while 100-500-G concentrations occur
  in areas with stronger downdrafts, in cell-like structures of diameter
  2-5 arcsec, the fields being aligned with dark intergranular lanes. It
  is inferred that granulation concentrates the magnetic field in the
  downflow lanes (as found in numerical simulations by Nordlund, 1983),
  and that the magnetic structures are more diffuse and longer-lasting
  than the bright spots; thus bright-point maps are contained in, rather
  than equivalent to, magnetic-field maps.

Title: On the Relation Between Large-Scale Granular Flows and
    Supergranules and Mesogranules
Authors: Simon, G.; Ferguson, S.; Tarbell, T.; Title, A.; Topka, K.;
   November, L.; Zirin, H.
Bibcode: 1987BAAS...19R.935S
Altcode:
  No abstract at ADS

Title: Simultaneous Observations of Emerging Flux from the Big Bear
    Solar Observatory and the SOUP Instrument on Spacelab 2
Authors: Topka, K.; Ferguson, S.; Title, A.; Tarbell, T.; Zirin, H.;
   Simon, G.; November, L.
Bibcode: 1987BAAS...19R.927T
Altcode:
  No abstract at ADS

Title: On the Feasibility of Correlation Tracking at Moderate
    Resolution
Authors: Bogart, R. S.; Scherrer, P. H.; Ferguson, S. H.; Tarbell,
   T. D.; Title, A. M.
Bibcode: 1987BAAS...19..941B
Altcode:
  No abstract at ADS

Title: Simultaneous Sunspot Observations from the SOUP Instrument
    on Spacelab 2 and the Big Bear Solar Observatory
Authors: Shine, R. A.; Title, A. M.; Topka, K. P.; Tarbell, T. D.;
   Zirin, H.
Bibcode: 1987BAAS...19..927S
Altcode:
  No abstract at ADS

Title: The Correlation Tracker Image Stabilization System for HRSO
Authors: Edwards, C. G.; Levay, M.; Gilbreth, C. W.; Tarbell, T. D.;
   Title, A. M.; Wolfson, C. J.; Torgerson, D. D.
Bibcode: 1987BAAS...19..929E
Altcode:
  No abstract at ADS

Title: Ocean Waves in the Photosphere: Measurements of Oscillations
    with Wavelengths of 1 - 10 Mm from SOUP White Light Images
Authors: Tarbell, T. D.; Shine, R. A.; Ferguson, S. H.; Title, A. M.;
   Leibacher, J. W.
Bibcode: 1987BAAS...19Q.936T
Altcode:
  No abstract at ADS

Title: Exploding and Elongated Granules
Authors: Title, A. M.; Tarbell, T. D.; Ferguson, S. H.; Topka, K. P.
Bibcode: 1987BAAS...19Q.927T
Altcode:
  No abstract at ADS

Title: New Ideas About Granulation Based on Data from the Solar
    Optical Universal Polarimeter Instrument on Spacelab 2 and Magnetic
    Data from Big Bear Solar Observatory
Authors: Title, A. M.; Tarbell, T. D.; Topka, K. P.; Shine, R. A.;
   Simon, G. W.; Zirin, H.; SOUP Team
Bibcode: 1987LNP...292..173T
Altcode: 1987ssp..conf..173T
  The SOUP flow fields have been compared with carefully aligned
  magnetograms taken at the BBSO before, during, and after the SOUP
  images. The magnetic field is observed to exist in locations where
  either the flow is convergent or on the boundaries of the outflow from
  a flow cell center. Streamlines calculated from the flow field agree
  very well with the observed motions of the magnetic field in the BBSO
  magnetogram movies.

Title: Properties of Granulation from Filtered Movies of Spacelab
    2 SOUP Images
Authors: Title, A. M.; Tarbell, T. D.
Bibcode: 1986BAAS...18Q.992T
Altcode:
  No abstract at ADS

Title: Measurements of Transverse Flows in the Solar Photosphere
    from Spacelab 2 SOUP Images
Authors: Tarbell, T. D.; Title, A. M.; Ferguson, S. H.; November,
   L. J.; Simon, G. W.
Bibcode: 1986BAAS...18R.992T
Altcode:
  No abstract at ADS

Title: High-Resolution Observations of Changing Magnetic Features
    on the Sun
Authors: Topka, K. P.; Tarbell, T. D.; Title, A. M.
Bibcode: 1986ApJ...306..304T
Altcode:
  The total magnetic flux present in 28 small isolated unipolar features
  that surround an active region has been measured on a well-registered
  sequence of high-resolution magnetograms. Seventeen features showed no
  changes, but the rest showed changes in measured flux with time that
  were much greater than the uncertainty in the flux determination. Two
  magnetic features showed evidence for increases in flux with time,
  while nine others showed decay. In some cases the decaying features
  appear to be canceling with nearby opposite polarity flux, which may
  represent the submergence of flux below the photosphere. In others,
  the observed decay occurs in regions that are strictly unipolar,
  with no observable opposite polarity flux present. Some evidence for
  the outward diffusion of flux from a decaying feature in a unipolar
  region was found.

Title: Properties of Solar Granulation in Magnetic versus Non-Magnetic
    Regions
Authors: Topka, K. P.; Tarbell, T. D.; SOUP Team
Bibcode: 1986BAAS...18..662T
Altcode:
  No abstract at ADS

Title: Measurements of the Lifetimes of Individual Granules from
    SOUP Data
Authors: Title, A. M.; Tarbell, T. D.; SOUP Team
Bibcode: 1986BAAS...18Q.661T
Altcode:
  No abstract at ADS

Title: Videodisk Movies of the Solar Photosphere from the SOUP
    Instrument on Spacelab 2
Authors: Tarbell, T. D.; Title, A. M.; SOUP Team
Bibcode: 1986BAAS...18R.661T
Altcode:
  No abstract at ADS

Title: Precise Proper Motion Measurement of Solar Granulation
Authors: November, L. J.; Simon, G. W.; Tarbell, T. D.; Title, A. M.
Bibcode: 1986BAAS...18..665N
Altcode:
  No abstract at ADS

Title: White-light movies of the solar photosphere from the soup
    instrument on spacelab 2
Authors: Title, A. M.; Tarbell, T. D.; Simon, G. W.; Acton, L.;
   Duncan, D.; Ferguson, S.; Finch, M.; Frank, Z.; Kelly, G.; Lindgren,
   R.; Morrill, M.; Pope, T.; Reeves, R.; Rehse, R.; Shine, R.; Topka,
   K.; Harvey, J.; Leibacher, J.; Livingston, W.; November, L.
Bibcode: 1986AdSpR...6h.253T
Altcode: 1986AdSpR...6..253T
  We present initial results on solar granulation, pores and sunspots
  from the white-light films obtained by the Solar Optical Universal
  Polarimeter (SOUP) instrument on Spacelab 2. SOUP contains a
  30-cm Cassegrain telescope, an active secondary mirror for image
  stabilization, and a white-light optical system with 35-mm film
  and video cameras. Outputs from the fine guidance servo provided
  engineering data on the performance of the ESA Instrument Pointing
  System (IPS). Several hours of movies were taken at various
  disk and limb positions in quiet and active regions. The images
  are diffraction-limited at 0.5 arc second resolution and are, of
  course, free of atmospheric seeing and distortion. Properties of the
  granulation in magnetic and non-magnetic regions are compared and are
  found to differ significantly in size, rate of intensity variation,
  and lifetime. In quiet sun on the order of fifty percent of the area
  has at least one ``exploding granule'' occurring in it during a 25
  minute period. Local correlation tracking has detected several types
  of transverse flows, including systematic outflow from the penumbral
  boundary of a spot, motion of penumbral filaments, and cellular flow
  patterns of supergranular and mesogranular size. Feature tracking has
  shown that in quiet sun the average granule fragment has a velocity
  of about one kilometer per second.

Title: An Initial Study of Granulation Using Data from the SOUP
    Instrument on SpaceLab 2
Authors: Tarbell, T. D.; Title, A. M.; SOUP Team
Bibcode: 1985BAAS...17..833T
Altcode:
  No abstract at ADS

Title: A High Quality Movie from the SOUP Instrument on SpaceLab 2
Authors: Title, A. M.; Tarbell, T. D.; SOUP Team
Bibcode: 1985BAAS...17..896T
Altcode:
  No abstract at ADS

Title: Scientific Observing Plans for the SOUP Instrument on Spacelab
    2 in July, 1985
Authors: Tarbell, T. D.; Finch, M. L.; Title, A. M.
Bibcode: 1985BAAS...17..641T
Altcode:
  No abstract at ADS

Title: Spectral imaging with a CID camera
Authors: Tarbell, T. D.
Bibcode: 1985lock.rept.....T
Altcode:
  The electron velocity distribution is calculated for an idealized model
  of the high electron mobility transistor using a many-particle Monte
  Carlo model and a self-consistent two-dimensional Poisson solver. Hot
  electron effects, nonstationary effects, and real space transfers
  are analyzed. The results show that significant velocity overshoot
  2.8 X 10 to the power 7th cm/s at 300 K and 3.7 X 10 to the 7th power
  cm/s at 77 K exits under the gate and that the velocity overshoot; is
  limited by both k-space transfer and real-space transfer. The value
  of the overshoot is limited by both k-space transfer and real-space
  transfer. The values of the overshoot velocities are much smaller that
  those obtained from the more conventional drift-diffusion model.

Title: Magnetic Fields, Downdrafts, and Granulation in the Solar
    Photosphere
Authors: Title, A. M.; Tarbell, T. D.
Bibcode: 1984BAAS...16.1001T
Altcode:
  No abstract at ADS

Title: X-ray, Ultraviolet, Optical and Magnetic Structure in and
    near an Active Region
Authors: Haisch, B. M.; Tarbell, T. D.; Bruner, M. E.; Acton, L. W.;
   Bonnet, R. M.; Hagyard, M. J.
Bibcode: 1984BAAS...16Q1002H
Altcode:
  No abstract at ADS

Title: High Resolution Observations of Magnetic Features on the Sun
Authors: Topka, K. P.; Tarbell, T. D.
Bibcode: 1984BAAS...16..991T
Altcode:
  No abstract at ADS

Title: High Spatial Resolution Magnetic Observation of an Active
    Region
Authors: Topka, K.; Tarbell, T.
Bibcode: 1984ssdp.conf..278T
Altcode:
  High spatial resolution magnetograms of an active region reveal
  apparent changes in the magnetic flux of small isolated features on
  time scales less than 30 minutes. Both flux increases and decreases
  are observed, sometimes for a single feature. These changes are seen
  in small unipolar magnetic regions with no obvious changes observed
  in any nearby opposite polarity features.

Title: Flux Changes in Small Magnetic Regions on the Sun
Authors: Topka, Ken P.; Tarbell, Ted
Bibcode: 1984BAAS...16Q.408T
Altcode:
  No abstract at ADS

Title: The Solar Optical Universal Polarimeter
Authors: Finch, Mike L.; Tarbell, Ted D.; Title, Alan M.
Bibcode: 1984BAAS...16..404F
Altcode:
  No abstract at ADS

Title: The Coordinated Instrument Package for the Solar Optical
    Telescope
Authors: Wolfson, C. J.; Tarbell, T. D.; Topka, K. P.; Title, A. M.
Bibcode: 1983BAAS...15R.718W
Altcode:
  No abstract at ADS

Title: A Real-Time Seeing Correction System for Solar Observations
Authors: Smithson, R. C.; Marshall, N. K.; Pope, T. P.; Sharbaugh,
   R. J.; Tarbell, T. D.
Bibcode: 1983BAAS...15R.717S
Altcode:
  No abstract at ADS

Title: Scientific Observing Plans for the SOT Coordinated Filtergraph
    Spectrograph
Authors: Tarbell, T. D.; Wolfson, C. J.; Topka, K. P.
Bibcode: 1983BAAS...15R.709T
Altcode:
  No abstract at ADS

Title: The rotation of horizontal-branch stars. I. Members of
    the field.
Authors: Peterson, R. C.; Tarbell, T. D.; Carney, B. W.
Bibcode: 1983ApJ...265..972P
Altcode:
  Multiple echelle spectra of eight field horizontal-branch stars at
  a resolution of 2.4 x 10 to the 4th are obtained. At least two stars
  exhibit intrinsically broadened lines. The line profiles of the broadest
  lined star are well resolved, and rotation is found unambiguously to
  be the cause of the broadening. It is pointed out that the inference
  that rotation is a rather common phenomenon in horizontal-branch
  stars has several ramifications for the normal stellar evolution of
  metal-poor stars. The rotation rates of the main-sequence stars implied
  if the angular momentum is primordial are discussed, together with the
  possibility that rotation was acquired during the giant-branch phase
  by angular momentum transfer from a companion.

Title: Fine Structure in the Solar Magnetic Field
Authors: Tarbell, T. D.; Title, A. M.
Bibcode: 1982BAAS...14..924T
Altcode:
  No abstract at ADS

Title: Low noise imaging photon counter for astronomy
Authors: Mertz, Lawrence N.; Tarbell, Theodore D.; Title, Alan M.
Bibcode: 1982ApOpt..21..628M
Altcode:
  No abstract at ADS

Title: The initialisation of a mesoscale weather prediction model
    using satellite and precipitation data
Authors: Tarbell, T. C.; Warner, T. T.; Wolcott, S. W.
Bibcode: 1981ESASP.165..259T
Altcode: 1981nmos.conf..259T
  No abstract at ADS

Title: Sensor Technology for Adaptive Mirror Systems Applied to
    Solar Astronomy
Authors: Smithson, R.; Tarbell, T.
Bibcode: 1981siwn.conf..480S
Altcode:
  No abstract at ADS

Title: The Rotation of Horizontal Branch Stars
Authors: Tarbell, T. D.; Peterson, R. C.
Bibcode: 1981BAAS...13..516T
Altcode:
  No abstract at ADS

Title: a Simple Image Motion Compensation System for Solar
    Observations
Authors: Tarbell, T.; Smithson, R.
Bibcode: 1981siwn.conf..491T
Altcode:
  No abstract at ADS

Title: Image Photon Counting System
Authors: Mertz, L.; Title, A.; Tarbell, T. D.
Bibcode: 1981BAAS...13..840M
Altcode:
  No abstract at ADS

Title: Image motion compensation on the Spacelab 2 Solar Optical
    Universal Polarimeter /SL2 SOUP/
Authors: Tarbell, T. D.; Duncan, D. W.; Finch, M. L.; Spence, G.
Bibcode: 1981SPIE..265...39T
Altcode:
  The SOUP experiment on Spacelab 2 includes a 30 cm visible light
  telescope and focal plane package mounted on the Instrument Pointing
  System (IPS). Scientific goals of the experiment dictate pointing
  stability requirements of less than 0.05 arcsecond jitter over periods
  of 5-20 seconds. Quantitative derivations of these requirements from
  two different aspects are presented: (1) avoidance of motion blurring
  of diffraction-limited images; (2) precise coalignment of consecutive
  frames to allow measurement of small image differences. To achieve this
  stability, a fine guider system capable of removing residual jitter of
  the IPS and image motions generated on the IPS cruciform instrument
  support structure has been constructed. This system uses solar limb
  detectors in the prime focal plane to derive an error signal. Image
  motion due to pointing errors is compensated by the agile secondary
  mirror mounted on piezoelectric transducers, controlled by a closed-loop
  servo system.

Title: Video image processor on the Spacelab 2 Solar Optical Universal
    Polarimeter /SL2 SOUP/
Authors: Lindgren, R. W.; Tarbell, T. D.
Bibcode: 1981SPIE..265...47L
Altcode:
  The SOUP instrument is designed to obtain diffraction-limited digital
  images of the sun with high photometric accuracy. The Video Processor
  originated from the requirement to provide onboard real-time image
  processing, both to reduce the telemetry rate and to provide meaningful
  video displays of scientific data to the payload crew. This original
  concept has evolved into a versatile digital processing system with
  a multitude of other uses in the SOUP program. The central element in
  the Video Processor design is a 16-bit central processing unit based on
  2900 family bipolar bit-slice devices. All arithmetic, logical and I/O
  operations are under control of microprograms, stored in programmable
  read-only memory and initiated by commands from the LSI-11. Several
  functions of the Video Processor are described, including interface
  to the High Rate Multiplexer downlink, cosmetic and scientific data
  processing, scan conversion for crew displays, focus and exposure
  testing, and use as ground support equipment.

Title: A Simple Image Motion Compensation System for Solar
    Observations
Authors: Smithson, R. C.; Tarbell, T. D.; Title, A. M.
Bibcode: 1980BAAS...12..915S
Altcode:
  No abstract at ADS

Title: Status of the Spacelab 2 Solar Optical Universal Polarimeter
    (SOUP)
Authors: Tarbell, T. D.; Finch, M. L.; Ramsey, H. E.; Schoolman,
   S. A.; Title, A. M.
Bibcode: 1980BAAS...12..915T
Altcode:
  No abstract at ADS

Title: Correlation Tracking Techniques as a Tool for Measuring Solar
    Transverse Velocities
Authors: Smithson, R. C.; Tarbell, T. D.
Bibcode: 1980BAAS...12..437S
Altcode:
  No abstract at ADS

Title: Using Tunable Filters for Two-Dimensional Solar Spectroscopy
Authors: Ramsey, H. B.; Schoolman, S. A.; Smithson, R. C.; Tarbell,
   T. D.; Title, A. M.
Bibcode: 1979BAAS...11..640R
Altcode:
  No abstract at ADS

Title: Problems in the Detection of Weak Magnetic Fields on the Sun
Authors: Tarbell, T. D.
Bibcode: 1979BAAS...11..631T
Altcode:
  No abstract at ADS

Title: In search of the perfect magnetogram.
Authors: Ramsey, H. E.; Schoolman, S. A.; Smithson, R. C.; Tarbell,
   T. D.; Title, A. M.
Bibcode: 1979BAAS...11..611R
Altcode:
  No abstract at ADS

Title: Weak and strong magnetic fields in the solar photosphere.
Authors: Tarbell, T. D.; Title, A. M.; Schoolman, S. A.
Bibcode: 1979ApJ...229..387T
Altcode:
  Very high-resolution (0.5 arcsec) magnetograms of the quiet sun
  and a plage are discussed which were obtained by using a tunable
  birefringent filter in Fe I 6302A. A search for a turbulent bipolar
  field with the use of co-added and spatially filtered frames is
  unsuccessful. Statistical analysis sets an upper limit of 50 gauss on
  the rms vertical component of such a field and probably rules out the
  possibility of field strengths exceeding 100 gauss in the inner network
  field observed at Kitt Peak. The area, total flux, and energy content
  of the strong (kilogauss) network fields are measured and compared with
  the upper limits for these properties of a hypothetical widespread
  weak field. In the quiet photosphere, a weak background field may
  contain interesting amounts of flux and energy, but the strong fields
  are dominant at higher levels and in the plage. The total magnetic
  energy in the quiet photospheric is roughly equal to the kinetic
  energy of granular and oscillatory velocities at the same level. By
  flux conservation, field strengths in the transition region are greater
  than 25 gauss in the quiet network and 100 gauss in the plage.

Title: Pseudo-Resolution of Solar Magnetic Flux Tubes in Faculae
Authors: Tarbell, T. D.
Bibcode: 1978BAAS...10..657T
Altcode:
  No abstract at ADS

Title: Correlation tracking study for meter-class solar telescope
    on space shuttle
Authors: Smithson, R. C.; Tarbell, T. D.
Bibcode: 1977lock.reptR....S
Altcode:
  The theory and expected performance level of correlation trackers used
  to control the pointing of a solar telescope in space using white
  light granulation as a target were studied. Three specific trackers
  were modeled and their performance levels predicted for telescopes of
  various apertures. The performance of the computer model trackers on
  computer enhanced granulation photographs was evaluated. Parametric
  equations for predicting tracker performance are presented.

Title: Measurements of magnetic fluxes and field strengths in the
    photospheric network.
Authors: Tarbell, T. D.; Title, A. M.
Bibcode: 1977SoPh...52...13T
Altcode:
  We present digital pictures of an active region network cell in five
  quantities, measured simultaneously: continuum intensity, line-center
  intensity, equivalent width, magnetogram signal, and magnetic field
  strength. These maps are derived from computer analysis of circularly
  polarized line profiles of FeI λ 5250.2; spectral and spatial
  resolution are 1/40 Å and 1.5″, respectively. Measured Zeeman
  splittings show the existence of strong magnetic fields (1000-1800 G)
  at nearly all points with a magnetogram signal exceeding 125 G. The
  mean and rms deviation of the field strengths change by less than
  20% over a factor-of-four range of fluxes. From the significant
  disparity between measured fluxes and field strengths, we conclude
  that large flux patches (up to 4″ across) consist of closely-packed
  unresolved filaments. The smallest filaments must be less than 0.7″
  in diameter. We also observe the dark component of the photospheric
  network, which appears to contain sizable transverse fields.

Title: Magnetic Field Strengths in Photospheric Filaments.
Authors: Tarbell, T. D.; Title, A. M.
Bibcode: 1976BAAS....8..501T
Altcode:
  No abstract at ADS

Title: Measurements of solar magnetic fields by Fourier transform
    techniques. II. Saturated and blended lines.
Authors: Tarbell, T. D.; Title, A. M.
Bibcode: 1976SoPh...47..563T
Altcode:
  The Fourier techniques of Paper I have been exhaustively calibrated
  using Unno's results for the absorption profile of a simple Zeeman
  triplet. If a simple transformation is applied to the normalized line
  depths, then magnetic field strengths and inclination angles can be
  measured very accurately from noisy, saturated line profiles. Systematic
  errors caused by saturation effects can be estimated and reduced by
  varying one parameter. When a significant fraction of the line profile
  is unsplit and unpolarized, large errors may be made in measurements
  of low fields, unless the line is sufficiently weak. For a weak line,
  a vertical field of 1600 gauss can be measured to 10% accuracy even
  when 70% of the line profile is stray light. These stray light
  errors are troublesome in measuring fields of gaps and pores but
  not sunspots. Numerical results of our error analysis are presented
  graphically.

Title: Erratum: the Triple-Alpha Rate, Screening Factors, and the
    Helium Flash
Authors: Tarbell, T. D.; Rood, R. T.
Bibcode: 1976ApJ...203..770T
Altcode:
  No abstract at ADS

Title: Semiconvection in halo stars and the primordial helium
    abundance
Authors: Tarbell, Theodore Dean
Bibcode: 1976PhDT.......116T
Altcode:
  No abstract at ADS

Title: Semiconvection in Halo Stars and the Primordial Helium
    Abundance.
Authors: Tarbell, T. D.
Bibcode: 1976PhDT.........3T
Altcode: 1976PhDT.......113T
  Convective overshooting and semiconvection in core-helium burning stars
  are studied. A necessary condition for the onset of semiconvection
  is derived, and the Schwarzschild neutrality criterion for the
  semiconvective zone is justified. Evolutionary sequences for horizontal
  branch stars in the globular cluster M3 are computed. They illustrate
  the effects of different treatments of overshooting and semiconvection,
  helium-burning nuclear reaction rates, and the primordial helium
  abundance. Evolutionary models for subdwarf B stars are computed
  which show excellent agreement with observed gravities and effective
  temperatures. These models are burning helium at their centers with
  thin, inert hydrogen envelopes. The hypothesis of mass loss at the
  helium flash can explain the small envelope masses and the observed
  gaps in the color distribution of blue halo stars. An upper limit
  to the initial helium abundance of sdB stars is derived from their
  light-to-mass ratios.

Title: The Triple-Alpha Rate, Screening Factors, and the Helium Flash
Authors: Tarbell, T. D.; Rood, K. T.
Bibcode: 1975ApJ...199..443T
Altcode:
  A simple but accurate stability analysis is presented for a degenerate
  stellar core containing a temperature-sensitive nuclear fuel. It is
  used to study the dependence of the helium core mass at the helium
  flash Mcf on the triple-a rate and its screening factor. Updated values
  of Mof are computed, and a sizable discrepancy between the results of
  different workers is removed. Subject headings: interiors, stellar -
  late-type stars - nuclear reactions - stellar evolution

Title: High Resolution Observations of Photospheric Network Magnetic
    Fields.
Authors: Tarbell, T. D.; Title, A. M.
Bibcode: 1975BAAS....7..459T
Altcode:
  No abstract at ADS

Title: Measurement of Solar Magnetic Fields by Fourier Transform
Techniques. I: Unsaturated Lines
Authors: Title, A. M.; Tarbell, T. D.
Bibcode: 1975SoPh...41..255T
Altcode:
  If the basic profile shapes of the normal Zeeman triplet do not have
  zeros in their Fourier transform, the magnetic field splitting can
  be determined independent of the profile shape. When the ratio of
  the splitting of the components is greater than the intrinsic FWHM
  of the component profiles the magnetic splitting can be determined
  with significantly greater accuracy than the measurement accuracy of
  the original profile. For Gaussian shaped components and a ratio of
  magnetic splitting to FWHM of 1.5 the noise reduction factor is 25.

Title: On the Accuracy of Measuring Magnetic Fields Using Fourier
    Transform Techniques
Authors: Tarbell, T. D.
Bibcode: 1975BAAS....7Q.351T
Altcode:
  No abstract at ADS

