Author name code: straus
ADS astronomy entries on 2022-09-14
author:"Straus, Thomas"
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Title: Linking Small-scale Solar Wind Properties with Large-scale
    Coronal Source Regions through Joint Parker Solar Probe-Metis/Solar
    Orbiter Observations
Authors: Telloni, Daniele; Zank, Gary P.; Sorriso-Valvo, Luca;
   D'Amicis, Raffaella; Panasenco, Olga; Susino, Roberto; Bruno, Roberto;
   Perrone, Denise; Adhikari, Laxman; Liang, Haoming; Nakanotani, Masaru;
   Zhao, Lingling; Hadid, Lina Z.; Sánchez-Cano, Beatriz; Verscharen,
   Daniel; Velli, Marco; Grimani, Catia; Marino, Raffaele; Carbone,
   Francesco; Mancuso, Salvatore; Biondo, Ruggero; Pagano, Paolo; Reale,
   Fabio; Bale, Stuart D.; Kasper, Justin C.; Case, Anthony W.; de Wit,
   Thierry Dudok; Goetz, Keith; Harvey, Peter R.; Korreck, Kelly E.;
   Larson, Davin; Livi, Roberto; MacDowall, Robert J.; Malaspina, David
   M.; Pulupa, Marc; Stevens, Michael L.; Whittlesey, Phyllis; Romoli,
   Marco; Andretta, Vincenzo; Deppo, Vania Da; Fineschi, Silvano; Heinzel,
   Petr; Moses, John D.; Naletto, Giampiero; Nicolini, Gianalfredo;
   Spadaro, Daniele; Stangalini, Marco; Teriaca, Luca; Capobianco,
   Gerardo; Capuano, Giuseppe E.; Casini, Chiara; Casti, Marta; Chioetto,
   Paolo; Corso, Alain J.; Leo, Yara De; Fabi, Michele; Frassati,
   Federica; Frassetto, Fabio; Giordano, Silvio; Guglielmino, Salvo L.;
   Jerse, Giovanna; Landini, Federico; Liberatore, Alessandro; Magli,
   Enrico; Massone, Giuseppe; Messerotti, Mauro; Pancrazzi, Maurizio;
   Pelizzo, Maria G.; Romano, Paolo; Sasso, Clementina; Schühle, Udo;
   Slemer, Alessandra; Straus, Thomas; Uslenghi, Michela; Volpicelli,
   Cosimo A.; Zangrilli, Luca; Zuppella, Paola; Abbo, Lucia; Auchère,
   Frédéric; Cuadrado, Regina Aznar; Berlicki, Arkadiusz; Ciaravella,
   Angela; Lamy, Philippe; Lanzafame, Alessandro; Malvezzi, Marco;
   Nicolosi, Piergiorgio; Nisticò, Giuseppe; Peter, Hardi; Solanki,
   Sami K.; Strachan, Leonard; Tsinganos, Kanaris; Ventura, Rita; Vial,
   Jean-Claude; Woch, Joachim; Zimbardo, Gaetano
Bibcode: 2022ApJ...935..112T
Altcode:
  The solar wind measured in situ by Parker Solar Probe in the very
  inner heliosphere is studied in combination with the remote-sensing
  observation of the coronal source region provided by the METIS
  coronagraph aboard Solar Orbiter. The coronal outflows observed near
  the ecliptic by Metis on 2021 January 17 at 16:30 UT, between 3.5 and
  6.3 R <SUB>⊙</SUB> above the eastern solar limb, can be associated
  with the streams sampled by PSP at 0.11 and 0.26 au from the Sun,
  in two time intervals almost 5 days apart. The two plasma flows
  come from two distinct source regions, characterized by different
  magnetic field polarity and intensity at the coronal base. It follows
  that both the global and local properties of the two streams are
  different. Specifically, the solar wind emanating from the stronger
  magnetic field region has a lower bulk flux density, as expected,
  and is in a state of well-developed Alfvénic turbulence, with low
  intermittency. This is interpreted in terms of slab turbulence in the
  context of nearly incompressible magnetohydrodynamics. Conversely,
  the highly intermittent and poorly developed turbulent behavior of the
  solar wind from the weaker magnetic field region is presumably due to
  large magnetic deflections most likely attributed to the presence of
  switchbacks of interchange reconnection origin.

Title: Cosmic-ray flux predictions and observations for and with
    Metis on board Solar Orbiter
Authors: Grimani, C.; Andretta, V.; Chioetto, P.; Da Deppo, V.; Fabi,
   M.; Gissot, S.; Naletto, G.; Persici, A.; Plainaki, C.; Romoli, M.;
   Sabbatini, F.; Spadaro, D.; Stangalini, M.; Telloni, D.; Uslenghi, M.;
   Antonucci, E.; Bemporad, A.; Capobianco, G.; Capuano, G.; Casti, M.;
   De Leo, Y.; Fineschi, S.; Frassati, F.; Frassetto, F.; Heinzel, P.;
   Jerse, G.; Landini, F.; Liberatore, A.; Magli, E.; Messerotti, M.;
   Moses, D.; Nicolini, G.; Pancrazzi, M.; Pelizzo, M. G.; Romano, P.;
   Sasso, C.; Schühle, U.; Slemer, A.; Straus, T.; Susino, R.; Teriaca,
   L.; Volpicelli, C. A.; Freiherr von Forstner, J. L.; Zuppella, P.
Bibcode: 2021A&A...656A..15G
Altcode: 2021arXiv210413700G
  Context. The Metis coronagraph is one of the remote sensing instruments
  hosted on board the ESA/NASA Solar Orbiter mission. Metis is devoted
  to carry out the first simultaneous imaging of the solar corona in
  both visible light (VL) and ultraviolet (UV). High-energy particles
  can penetrate spacecraft materials and may limit the performance of
  the on-board instruments. A study of the galactic cosmic-ray (GCR)
  tracks observed in the first VL images gathered by Metis during the
  commissioning phase is presented here. A similar analysis is planned
  for the UV channel. <BR /> Aims: We aim to formulate a prediction of
  the GCR flux up to hundreds of GeV for the first part of the Solar
  Orbiter mission to study the performance of the Metis coronagraph. <BR
  /> Methods: The GCR model predictions are compared to observations
  gathered on board Solar Orbiter by the High-Energy Telescope in the
  range between 10 MeV and 100 MeV in the summer of 2020 as well as with
  the previous measurements. Estimated cosmic-ray fluxes above 70 MeV
  n<SUP>−1</SUP> have been also parameterized and used for Monte Carlo
  simulations aimed at reproducing the cosmic-ray track observations in
  the Metis coronagraph VL images. The same parameterizations can also
  be used to study the performance of other detectors. <BR /> Results:
  By comparing observations of cosmic-ray tracks in the Metis VL images
  with FLUKA Monte Carlo simulations of cosmic-ray interactions in
  the VL detector, we find that cosmic rays fire only a fraction, on
  the order of 10<SUP>−4</SUP>, of the whole image pixel sample. We
  also find that the overall efficiency for cosmic-ray identification
  in the Metis VL images is approximately equal to the contribution
  of Z ≥ 2 GCR particles. A similar study will be carried out during
  the whole of the Solar Orbiter's mission duration for the purposes of
  instrument diagnostics and to verify whether the Metis data and Monte
  Carlo simulations would allow for a long-term monitoring of the GCR
  proton flux.

Title: First light observations of the solar wind in the outer corona
    with the Metis coronagraph
Authors: Romoli, M.; Antonucci, E.; Andretta, V.; Capuano, G. E.; Da
   Deppo, V.; De Leo, Y.; Downs, C.; Fineschi, S.; Heinzel, P.; Landini,
   F.; Liberatore, A.; Naletto, G.; Nicolini, G.; Pancrazzi, M.; Sasso,
   C.; Spadaro, D.; Susino, R.; Telloni, D.; Teriaca, L.; Uslenghi,
   M.; Wang, Y. -M.; Bemporad, A.; Capobianco, G.; Casti, M.; Fabi, M.;
   Frassati, F.; Frassetto, F.; Giordano, S.; Grimani, C.; Jerse, G.;
   Magli, E.; Massone, G.; Messerotti, M.; Moses, D.; Pelizzo, M. -G.;
   Romano, P.; Schühle, U.; Slemer, A.; Stangalini, M.; Straus, T.;
   Volpicelli, C. A.; Zangrilli, L.; Zuppella, P.; Abbo, L.; Auchère,
   F.; Aznar Cuadrado, R.; Berlicki, A.; Bruno, R.; Ciaravella, A.;
   D'Amicis, R.; Lamy, P.; Lanzafame, A.; Malvezzi, A. M.; Nicolosi,
   P.; Nisticò, G.; Peter, H.; Plainaki, C.; Poletto, L.; Reale, F.;
   Solanki, S. K.; Strachan, L.; Tondello, G.; Tsinganos, K.; Velli,
   M.; Ventura, R.; Vial, J. -C.; Woch, J.; Zimbardo, G.
Bibcode: 2021A&A...656A..32R
Altcode: 2021arXiv210613344R
  In this work, we present an investigation of the wind in the solar
  corona that has been initiated by observations of the resonantly
  scattered ultraviolet emission of the coronal plasma obtained with
  UVCS-SOHO, designed to measure the wind outflow speed by applying
  Doppler dimming diagnostics. Metis on Solar Orbiter complements the
  UVCS spectroscopic observations that were performed during solar
  activity cycle 23 by simultaneously imaging the polarized visible
  light and the H I Lyman-α corona in order to obtain high spatial and
  temporal resolution maps of the outward velocity of the continuously
  expanding solar atmosphere. The Metis observations, taken on May 15,
  2020, provide the first H I Lyman-α images of the extended corona
  and the first instantaneous map of the speed of the coronal plasma
  outflows during the minimum of solar activity and allow us to identify
  the layer where the slow wind flow is observed. The polarized visible
  light (580-640 nm) and the ultraviolet H I Lyα (121.6 nm) coronal
  emissions, obtained with the two Metis channels, were combined in
  order to measure the dimming of the UV emission relative to a static
  corona. This effect is caused by the outward motion of the coronal
  plasma along the direction of incidence of the chromospheric photons
  on the coronal neutral hydrogen. The plasma outflow velocity was then
  derived as a function of the measured Doppler dimming. The static
  corona UV emission was simulated on the basis of the plasma electron
  density inferred from the polarized visible light. This study leads
  to the identification, in the velocity maps of the solar corona, of
  the high-density layer about ±10° wide, centered on the extension
  of a quiet equatorial streamer present at the east limb - the coronal
  origin of the heliospheric current sheet - where the slowest wind
  flows at about 160 ± 18 km s<SUP>−1</SUP> from 4 R<SUB>⊙</SUB>
  to 6 R<SUB>⊙</SUB>. Beyond the boundaries of the high-density layer,
  the wind velocity rapidly increases, marking the transition between
  slow and fast wind in the corona.

Title: Exploring the Solar Wind from Its Source on the Corona into
    the Inner Heliosphere during the First Solar Orbiter-Parker Solar
    Probe Quadrature
Authors: Telloni, Daniele; Andretta, Vincenzo; Antonucci, Ester;
   Bemporad, Alessandro; Capuano, Giuseppe E.; Fineschi, Silvano;
   Giordano, Silvio; Habbal, Shadia; Perrone, Denise; Pinto, Rui F.;
   Sorriso-Valvo, Luca; Spadaro, Daniele; Susino, Roberto; Woodham, Lloyd
   D.; Zank, Gary P.; Romoli, Marco; Bale, Stuart D.; Kasper, Justin C.;
   Auchère, Frédéric; Bruno, Roberto; Capobianco, Gerardo; Case,
   Anthony W.; Casini, Chiara; Casti, Marta; Chioetto, Paolo; Corso,
   Alain J.; Da Deppo, Vania; De Leo, Yara; Dudok de Wit, Thierry;
   Frassati, Federica; Frassetto, Fabio; Goetz, Keith; Guglielmino,
   Salvo L.; Harvey, Peter R.; Heinzel, Petr; Jerse, Giovanna; Korreck,
   Kelly E.; Landini, Federico; Larson, Davin; Liberatore, Alessandro;
   Livi, Roberto; MacDowall, Robert J.; Magli, Enrico; Malaspina, David
   M.; Massone, Giuseppe; Messerotti, Mauro; Moses, John D.; Naletto,
   Giampiero; Nicolini, Gianalfredo; Nisticò, Giuseppe; Panasenco,
   Olga; Pancrazzi, Maurizio; Pelizzo, Maria G.; Pulupa, Marc; Reale,
   Fabio; Romano, Paolo; Sasso, Clementina; Schühle, Udo; Stangalini,
   Marco; Stevens, Michael L.; Strachan, Leonard; Straus, Thomas; Teriaca,
   Luca; Uslenghi, Michela; Velli, Marco; Verscharen, Daniel; Volpicelli,
   Cosimo A.; Whittlesey, Phyllis; Zangrilli, Luca; Zimbardo, Gaetano;
   Zuppella, Paola
Bibcode: 2021ApJ...920L..14T
Altcode: 2021arXiv211011031T
  This Letter addresses the first Solar Orbiter (SO)-Parker Solar
  Probe (PSP) quadrature, occurring on 2021 January 18 to investigate
  the evolution of solar wind from the extended corona to the inner
  heliosphere. Assuming ballistic propagation, the same plasma volume
  observed remotely in the corona at altitudes between 3.5 and 6.3
  solar radii above the solar limb with the Metis coronagraph on SO
  can be tracked to PSP, orbiting at 0.1 au, thus allowing the local
  properties of the solar wind to be linked to the coronal source region
  from where it originated. Thanks to the close approach of PSP to the
  Sun and the simultaneous Metis observation of the solar corona, the
  flow-aligned magnetic field and the bulk kinetic energy flux density
  can be empirically inferred along the coronal current sheet with an
  unprecedented accuracy, allowing in particular estimation of the Alfvén
  radius at 8.7 solar radii during the time of this event. This is thus
  the very first study of the same solar wind plasma as it expands from
  the sub-Alfvénic solar corona to just above the Alfvén surface.

Title: In-flight optical performance assessment for the Metis solar
    coronagraph
Authors: Da Deppo, Vania; Chioetto, Paolo; Andretta, Vincenzo; Casini,
   Chiara; Frassetto, Fabio; Slemer, Alessandra; Zuppella, Paola; Romoli,
   Marco; Fineschi, Silvano; Heinzel, Petr; Naletto, Giampiero; Nicolini,
   Gianalfredo; Spadaro, Daniele; Stangalini, Marco; Teriaca, Luca;
   Bemporad, Alessandro; Casti, Marta; Fabi, Michele; Grimani, Catia;
   Heerlein, Klaus; Jerse, Giovanna; Landini, Federico; Liberatore,
   Alessandro; Magli, Enrico; Melich, Radek; Pancrazzi, Maurizio; Pelizzo,
   Maria-G.; Romano, Paolo; Sasso, Clementina; Straus, Thomas; Susino,
   Roberto; Uslenghi, Michela; Volpicelli, Cosimo Antonio
Bibcode: 2021SPIE11852E..10D
Altcode:
  Metis is a multi-wavelength coronagraph onboard the European Space
  Agency (ESA) Solar Orbiter mission. The instrument features an
  innovative instrument design conceived for simultaneously imaging the
  Sun's corona in the visible and ultraviolet range. The Metis visible
  channel employs broad-band, polarized imaging of the visible K-corona,
  while the UV one uses narrow-band imaging at the HI Ly 􀄮, i.e. 121.6
  nm. During the commissioning different acquisitions and activities,
  performed with both the Metis channels, have been carried out with the
  aim to check the functioning and the performance of the instrument. In
  particular, specific observations of stars have been devised to assess
  the optical alignment of the telescope and to derive the instrument
  optical parameters such as focal length, PSF and possibly check the
  optical distortion and the vignetting function. In this paper, the
  preliminary results obtained for the PSF of both channels and the
  determination of the scale for the visible channel will be described
  and discussed. The in-flight obtained data will be compared to those
  obtained on-ground during the calibration campaign.

Title: On-ground flat-field calibration of the Metis coronagraph
    onboard the Solar Orbiter ESA mission
Authors: Casini, C.; Da Deppo, V.; Zuppella, P.; Chioetto, P.; Slemer,
   A.; Frassetto, F.; Romoli, M.; Landini, F.; Pancrazzi, M.; Andretta,
   V.; De Leo, Y.; Bemporad, A.; Fabi, M.; Fineschi, S.; Frassati, F.;
   Grimani, C.; Jerse, G.; Heerlein, K.; Liberatore, A.; Magli, E.;
   Naletto, G.; Nicolini, G.; Pelizzo, M. G.; Romano, P.; Sasso, C.;
   Spadaro, D.; Stangalini, M.; Straus, T.; Susino, R.; Teriaca, L.;
   Uslenghi, M.; Casti, M.; Heinzel, P.; Volpicelli, A.
Bibcode: 2021SPIE11852E..5BC
Altcode:
  Solar Orbiter, launched on February 9<SUP>th</SUP> 2020, is an
  ESA/NASA mission conceived to study the Sun. This work presents
  the embedded Metis coronagraph and its on-ground calibration in the
  580-640 nm wavelength range using a flat field panel. It provides
  a uniform illumination to evaluate the response of each pixel of
  the detector; and to characterize the Field of View (FoV) of the
  coronagraph. Different images with different exposure times were
  acquired during the on-ground calibration campaign. They were analyzed
  to verify the linearity response of the instrument and the requirements
  for the FoV: the maximum area of the sky that Metis can acquire.

Title: Challenges during Metis-Solar Orbiter commissioning phase
Authors: Romoli, Marco; Andretta, Vincenzo; Bemporad, Alessandro;
   Casti, Marta; Da Deppo, Vania; De Leo, Yara; Fabi, Michele; Fineschi,
   Silvano; Frassetto, Fabio; Grimani, Catia; Heerlein, Klaus; Heinzel,
   Petr; Jerse, Giovanna; Landini, Federico; Liberatore, Alessandro;
   Magli, Enrico; Naletto, Giampiero; Nicolini, Gianalfredo; Pancrazzi,
   Maurizio; Pelizzo, Maria Guglielmina; Romano, Paolo; Sasso, Clementina;
   Schühle, Udo; Slemer, Alessandra; Spadaro, Daniele; Straus, Thomas;
   Susino, Roberto; Teriaca, Luca; Uslenghi, Michela; Volpicelli, Cosimo
   Antonio; Zupella, Paola
Bibcode: 2021SPIE11852E..5AR
Altcode:
  Metis is the visible light and UV light imaging coronagraph on board
  the ESA-NASA mission Solar Orbiter that has been launched February 10th,
  2020, from Cape Canaveral. Scope of the mission is to study the Sun up
  close, taking high-resolution images of the Sun's poles for the first
  time, and understanding the Sun-Earth connection. Metis coronagraph
  will image the solar corona in the linearly polarized broadband visible
  radiation and in the UV HI Ly-α line from 1.6 to 3 solar radii when at
  Solar Orbiter perihelion, providing a diagnostics, with unprecedented
  temporal coverage and spatial resolution, of the structures and dynamics
  of the full corona. Solar Orbiter commissioning phase big challenge was
  Covid-19 social distancing phase that affected the way commissioning
  of a spacecraft and its payload is typically done. Metis coronagraph
  on-board Solar Orbiter had its additional challenges: to wake up and
  check the performance of the optical, electrical and thermal subsystems,
  most of them unchecked since Metis delivery to spacecraft prime, Airbus,
  in May 2017. The roadmap to the fully commissioned coronagraph is here
  described throughout the steps from the software functional test,
  the switch on of the detectors of the two channels, UV and visible,
  to the optimization of the occulting system and the characterization
  of the instrumental stray light, one of the most challenging features
  in a coronagraph.

Title: In-flight calibration of Metis coronagraph on board of
    Solar Orbiter
Authors: Liberatore, A.; Fineschi, S.; Casti, M.; Capobianco, G.;
   Romoli, M.; Andretta, V.; Bemporad, A.; Da Deppo, V.; De Leo, Y.; Fabi,
   M.; Frassetto, F.; Grimani, C.; Heerlein, K.; Heinzel, P.; Jerse,
   G.; Landini, F.; Magli, E.; Naletto, G.; Nicolini, G.; Pancrazzi,
   M.; Pelizzo, M. G.; Romano, P.; Sasso, C.; Slemer, A.; Spadaro, D.;
   Straus, T.; Susino, R.; Teriaca, L.; Uslenghi, M.; Volpicelli, C. A.;
   Zuppella, P.
Bibcode: 2021SPIE11852E..48L
Altcode:
  Metis coronagraph is one of the remote-sensing instruments of the Solar
  Orbiter mission launched at the begin of 2020. The mission profile will
  allow for the first time the remote-sensing observation of the Sun
  from a very close distance and increasing the latitude with respect
  to the ecliptic plane. In particular, Metis is aimed at the overall
  characterization and study of the solar corona and solar wind. Metis
  instrument acquires images of the solar corona in two different
  wavelengths simultaneously; ultraviolet (UV) and visible-light (VL). The
  VL channel includes a polarimeter with an electro-optically modulating
  Liquid Crystal Variable Retarder (LCVR) to measure the linearly
  polarized brighness pB) of the K-corona. This paper presents part of
  the in-flight calibration results for both wavelength channels together
  with a comparison with on-ground calibrations. The orientation of the
  K-corona linear polarization was used for the in-flight calibration
  of the Metis polarimeter. This paper describes the correction of the
  on-ground VL vignetting function after the in-flight adjustment of
  the internal occulter. The same vignetting function was adaptated to
  the UV channel.

Title: The signature of granulation in a solar power spectrum as
    seen with CO<SUP>5</SUP>BOLD
Authors: Lundkvist, Mia S.; Ludwig, Hans-Günter; Collet, Remo;
   Straus, Thomas
Bibcode: 2021MNRAS.501.2512L
Altcode: 2020arXiv201110045L; 2020MNRAS.tmp.3425L
  The granulation background seen in the power spectrum of a solar-like
  oscillator poses a serious challenge for extracting precise and detailed
  information about the stellar oscillations. Using a 3D hydrodynamical
  simulation of the Sun computed with CO<SUP>5</SUP>BOLD, we investigate
  various background models to infer, using a Bayesian methodology,
  which one provides the best fit to the background in the simulated
  power spectrum. We find that the best fit is provided by an expression
  including the overall power level and two characteristic frequencies,
  one with an exponent of two and one with a free exponent taking on a
  value around six. We assess the impact of the 3D hydro-code on this
  result by repeating the analysis with a simulation from S TAGGER and
  find that the main conclusion is unchanged. However, the details of
  the resulting best fits differ slightly between the two codes, but we
  explain this difference by studying the effect of the spatial resolution
  and the duration of the simulation on the fit. Additionally, we look
  into the impact of adding white noise to the simulated time series as
  a simple way to mimic a real star. We find that, as long as the noise
  level is not too low, the results are consistent with the no-noise case.

Title: The MDOR/PDOR on-line module for MISO, the planning software
    of Solar Orbiter instruments
Authors: Volpicelli, Cosimo; Landini, Federico; Pancrazzi, Maurizio;
   Straus, Thomas; Susino, Roberto; Nicolini, Gianalfredo; Sasso,
   Clementina; Fabi, Michele; De Leo, Yara; Casini, Chiara; Naletto,
   Giampiero; Nicolosi, Piergiorgio; Spadaro, Daniele; Andretta, Vincenzo;
   Antonucci, Ester; Fineschi, Silvano; Da Deppo, Vania; Zuppella, Paola;
   Frassetto, Fabio; Slemer, Alessandra; Mercier, Claude; Kouliche,
   Dimitri; Caminade, Stephane; Picard, David; Buchlin, Eric; Auchère,
   Frédéric; Romoli, Marco
Bibcode: 2020SPIE11452E..0SV
Altcode:
  Solar Orbiter is a solar mission that will approach the Sun down to a
  minimum perihelion of 0.28 AU and will increase its orbit inclination
  with respect to the ecliptic up to a maximum angle of 34 deg. For
  imagers aboard Solar Orbiter there will be three 10-days remote sensing
  windows per orbit. Observations shall be carefully planned at least 6
  months in advance. The Multi Instrument Sequence Organizer (MISO) is
  a web based platform developed by the SPICE group and made available
  to support Solar Orbiter instruments teams in planning observations
  by assembling Mission Database sequences. Metis is the UV and visible
  light coronagraph aboard Solar Orbiter. Metis is a complex instrument
  characterized by a rich variety of observing modes, which required a
  careful commissioning activity and will need support for potential
  maintenance operations throughout the mission. In order to support
  commissioning and maintenance activities, the Metis team developed
  a PDOR (Payload Direct Operation Request) and MDOR (Memory Direct
  Operation Request) module integrated in MISO and made available to all
  Solar Orbiter instruments. An effort was made in order to interpret
  the coding philosophy of the main project and to make the additional
  module as homogeneous as possible both to the web interface and to the
  algorithm logic, while integrating characteristics which are peculiar
  to PDORs and MDORs. An user friendly web based interface allows the
  operator to build the operation request and to successively modify or
  integrate it with further or alternative information. In the present
  work we describe the PDOR/MDOR module for MISO by addressing its logic
  and main characteristics.

Title: Coordination within the remote sensing payload on the Solar
    Orbiter mission
Authors: Auchère, F.; Andretta, V.; Antonucci, E.; Bach, N.;
   Battaglia, M.; Bemporad, A.; Berghmans, D.; Buchlin, E.; Caminade,
   S.; Carlsson, M.; Carlyle, J.; Cerullo, J. J.; Chamberlin, P. C.;
   Colaninno, R. C.; Davila, J. M.; De Groof, A.; Etesi, L.; Fahmy,
   S.; Fineschi, S.; Fludra, A.; Gilbert, H. R.; Giunta, A.; Grundy,
   T.; Haberreiter, M.; Harra, L. K.; Hassler, D. M.; Hirzberger, J.;
   Howard, R. A.; Hurford, G.; Kleint, L.; Kolleck, M.; Krucker, S.;
   Lagg, A.; Landini, F.; Long, D. M.; Lefort, J.; Lodiot, S.; Mampaey,
   B.; Maloney, S.; Marliani, F.; Martinez-Pillet, V.; McMullin, D. R.;
   Müller, D.; Nicolini, G.; Orozco Suarez, D.; Pacros, A.; Pancrazzi,
   M.; Parenti, S.; Peter, H.; Philippon, A.; Plunkett, S.; Rich, N.;
   Rochus, P.; Rouillard, A.; Romoli, M.; Sanchez, L.; Schühle, U.;
   Sidher, S.; Solanki, S. K.; Spadaro, D.; St Cyr, O. C.; Straus, T.;
   Tanco, I.; Teriaca, L.; Thompson, W. T.; del Toro Iniesta, J. C.;
   Verbeeck, C.; Vourlidas, A.; Watson, C.; Wiegelmann, T.; Williams,
   D.; Woch, J.; Zhukov, A. N.; Zouganelis, I.
Bibcode: 2020A&A...642A...6A
Altcode:
  Context. To meet the scientific objectives of the mission, the Solar
  Orbiter spacecraft carries a suite of in-situ (IS) and remote sensing
  (RS) instruments designed for joint operations with inter-instrument
  communication capabilities. Indeed, previous missions have shown that
  the Sun (imaged by the RS instruments) and the heliosphere (mainly
  sampled by the IS instruments) should be considered as an integrated
  system rather than separate entities. Many of the advances expected
  from Solar Orbiter rely on this synergistic approach between IS and
  RS measurements. <BR /> Aims: Many aspects of hardware development,
  integration, testing, and operations are common to two or more
  RS instruments. In this paper, we describe the coordination effort
  initiated from the early mission phases by the Remote Sensing Working
  Group. We review the scientific goals and challenges, and give an
  overview of the technical solutions devised to successfully operate
  these instruments together. <BR /> Methods: A major constraint for the
  RS instruments is the limited telemetry (TM) bandwidth of the Solar
  Orbiter deep-space mission compared to missions in Earth orbit. Hence,
  many of the strategies developed to maximise the scientific return from
  these instruments revolve around the optimisation of TM usage, relying
  for example on onboard autonomy for data processing, compression,
  and selection for downlink. The planning process itself has been
  optimised to alleviate the dynamic nature of the targets, and an
  inter-instrument communication scheme has been implemented which can
  be used to autonomously alter the observing modes. We also outline the
  plans for in-flight cross-calibration, which will be essential to the
  joint data reduction and analysis. <BR /> Results: The RS instrument
  package on Solar Orbiter will carry out comprehensive measurements
  from the solar interior to the inner heliosphere. Thanks to the close
  coordination between the instrument teams and the European Space
  Agency, several challenges specific to the RS suite were identified
  and addressed in a timely manner.

Title: Models and data analysis tools for the Solar Orbiter mission
Authors: Rouillard, A. P.; Pinto, R. F.; Vourlidas, A.; De Groof, A.;
   Thompson, W. T.; Bemporad, A.; Dolei, S.; Indurain, M.; Buchlin, E.;
   Sasso, C.; Spadaro, D.; Dalmasse, K.; Hirzberger, J.; Zouganelis, I.;
   Strugarek, A.; Brun, A. S.; Alexandre, M.; Berghmans, D.; Raouafi,
   N. E.; Wiegelmann, T.; Pagano, P.; Arge, C. N.; Nieves-Chinchilla,
   T.; Lavarra, M.; Poirier, N.; Amari, T.; Aran, A.; Andretta, V.;
   Antonucci, E.; Anastasiadis, A.; Auchère, F.; Bellot Rubio, L.;
   Nicula, B.; Bonnin, X.; Bouchemit, M.; Budnik, E.; Caminade, S.;
   Cecconi, B.; Carlyle, J.; Cernuda, I.; Davila, J. M.; Etesi, L.;
   Espinosa Lara, F.; Fedorov, A.; Fineschi, S.; Fludra, A.; Génot,
   V.; Georgoulis, M. K.; Gilbert, H. R.; Giunta, A.; Gomez-Herrero, R.;
   Guest, S.; Haberreiter, M.; Hassler, D.; Henney, C. J.; Howard, R. A.;
   Horbury, T. S.; Janvier, M.; Jones, S. I.; Kozarev, K.; Kraaikamp,
   E.; Kouloumvakos, A.; Krucker, S.; Lagg, A.; Linker, J.; Lavraud,
   B.; Louarn, P.; Maksimovic, M.; Maloney, S.; Mann, G.; Masson, A.;
   Müller, D.; Önel, H.; Osuna, P.; Orozco Suarez, D.; Owen, C. J.;
   Papaioannou, A.; Pérez-Suárez, D.; Rodriguez-Pacheco, J.; Parenti,
   S.; Pariat, E.; Peter, H.; Plunkett, S.; Pomoell, J.; Raines, J. M.;
   Riethmüller, T. L.; Rich, N.; Rodriguez, L.; Romoli, M.; Sanchez,
   L.; Solanki, S. K.; St Cyr, O. C.; Straus, T.; Susino, R.; Teriaca,
   L.; del Toro Iniesta, J. C.; Ventura, R.; Verbeeck, C.; Vilmer, N.;
   Warmuth, A.; Walsh, A. P.; Watson, C.; Williams, D.; Wu, Y.; Zhukov,
   A. N.
Bibcode: 2020A&A...642A...2R
Altcode:
  Context. The Solar Orbiter spacecraft will be equipped with a wide
  range of remote-sensing (RS) and in situ (IS) instruments to record
  novel and unprecedented measurements of the solar atmosphere and
  the inner heliosphere. To take full advantage of these new datasets,
  tools and techniques must be developed to ease multi-instrument and
  multi-spacecraft studies. In particular the currently inaccessible
  low solar corona below two solar radii can only be observed
  remotely. Furthermore techniques must be used to retrieve coronal
  plasma properties in time and in three dimensional (3D) space. Solar
  Orbiter will run complex observation campaigns that provide interesting
  opportunities to maximise the likelihood of linking IS data to their
  source region near the Sun. Several RS instruments can be directed
  to specific targets situated on the solar disk just days before
  data acquisition. To compare IS and RS, data we must improve our
  understanding of how heliospheric probes magnetically connect to the
  solar disk. <BR /> Aims: The aim of the present paper is to briefly
  review how the current modelling of the Sun and its atmosphere
  can support Solar Orbiter science. We describe the results of a
  community-led effort by European Space Agency's Modelling and Data
  Analysis Working Group (MADAWG) to develop different models, tools,
  and techniques deemed necessary to test different theories for the
  physical processes that may occur in the solar plasma. The focus here
  is on the large scales and little is described with regards to kinetic
  processes. To exploit future IS and RS data fully, many techniques have
  been adapted to model the evolving 3D solar magneto-plasma from the
  solar interior to the solar wind. A particular focus in the paper is
  placed on techniques that can estimate how Solar Orbiter will connect
  magnetically through the complex coronal magnetic fields to various
  photospheric and coronal features in support of spacecraft operations
  and future scientific studies. <BR /> Methods: Recent missions such as
  STEREO, provided great opportunities for RS, IS, and multi-spacecraft
  studies. We summarise the achievements and highlight the challenges
  faced during these investigations, many of which motivated the Solar
  Orbiter mission. We present the new tools and techniques developed
  by the MADAWG to support the science operations and the analysis of
  the data from the many instruments on Solar Orbiter. <BR /> Results:
  This article reviews current modelling and tool developments that ease
  the comparison of model results with RS and IS data made available
  by current and upcoming missions. It also describes the modelling
  strategy to support the science operations and subsequent exploitation
  of Solar Orbiter data in order to maximise the scientific output
  of the mission. <BR /> Conclusions: The on-going community effort
  presented in this paper has provided new models and tools necessary
  to support mission operations as well as the science exploitation of
  the Solar Orbiter data. The tools and techniques will no doubt evolve
  significantly as we refine our procedure and methodology during the
  first year of operations of this highly promising mission.

Title: Metis: the Solar Orbiter visible light and ultraviolet
    coronal imager
Authors: Antonucci, Ester; Romoli, Marco; Andretta, Vincenzo; Fineschi,
   Silvano; Heinzel, Petr; Moses, J. Daniel; Naletto, Giampiero; Nicolini,
   Gianalfredo; Spadaro, Daniele; Teriaca, Luca; Berlicki, Arkadiusz;
   Capobianco, Gerardo; Crescenzio, Giuseppe; Da Deppo, Vania; Focardi,
   Mauro; Frassetto, Fabio; Heerlein, Klaus; Landini, Federico; Magli,
   Enrico; Marco Malvezzi, Andrea; Massone, Giuseppe; Melich, Radek;
   Nicolosi, Piergiorgio; Noci, Giancarlo; Pancrazzi, Maurizio; Pelizzo,
   Maria G.; Poletto, Luca; Sasso, Clementina; Schühle, Udo; Solanki,
   Sami K.; Strachan, Leonard; Susino, Roberto; Tondello, Giuseppe;
   Uslenghi, Michela; Woch, Joachim; Abbo, Lucia; Bemporad, Alessandro;
   Casti, Marta; Dolei, Sergio; Grimani, Catia; Messerotti, Mauro;
   Ricci, Marco; Straus, Thomas; Telloni, Daniele; Zuppella, Paola;
   Auchère, Frederic; Bruno, Roberto; Ciaravella, Angela; Corso,
   Alain J.; Alvarez Copano, Miguel; Aznar Cuadrado, Regina; D'Amicis,
   Raffaella; Enge, Reiner; Gravina, Alessio; Jejčič, Sonja; Lamy,
   Philippe; Lanzafame, Alessandro; Meierdierks, Thimo; Papagiannaki,
   Ioanna; Peter, Hardi; Fernandez Rico, German; Giday Sertsu, Mewael;
   Staub, Jan; Tsinganos, Kanaris; Velli, Marco; Ventura, Rita; Verroi,
   Enrico; Vial, Jean-Claude; Vives, Sebastien; Volpicelli, Antonio;
   Werner, Stephan; Zerr, Andreas; Negri, Barbara; Castronuovo, Marco;
   Gabrielli, Alessandro; Bertacin, Roberto; Carpentiero, Rita; Natalucci,
   Silvia; Marliani, Filippo; Cesa, Marco; Laget, Philippe; Morea, Danilo;
   Pieraccini, Stefano; Radaelli, Paolo; Sandri, Paolo; Sarra, Paolo;
   Cesare, Stefano; Del Forno, Felice; Massa, Ernesto; Montabone, Mauro;
   Mottini, Sergio; Quattropani, Daniele; Schillaci, Tiziano; Boccardo,
   Roberto; Brando, Rosario; Pandi, Arianna; Baietto, Cristian; Bertone,
   Riccardo; Alvarez-Herrero, Alberto; García Parejo, Pilar; Cebollero,
   María; Amoruso, Mauro; Centonze, Vito
Bibcode: 2020A&A...642A..10A
Altcode: 2019arXiv191108462A
  <BR /> Aims: Metis is the first solar coronagraph designed for a
  space mission and is capable of performing simultaneous imaging of the
  off-limb solar corona in both visible and UV light. The observations
  obtained with Metis aboard the Solar Orbiter ESA-NASA observatory
  will enable us to diagnose, with unprecedented temporal coverage and
  spatial resolution, the structures and dynamics of the full corona
  in a square field of view (FoV) of ±2.9° in width, with an inner
  circular FoV at 1.6°, thus spanning the solar atmosphere from 1.7
  R<SUB>⊙</SUB> to about 9 R<SUB>⊙</SUB>, owing to the eccentricity
  of the spacecraft orbit. Due to the uniqueness of the Solar Orbiter
  mission profile, Metis will be able to observe the solar corona
  from a close (0.28 AU, at the closest perihelion) vantage point,
  achieving increasing out-of-ecliptic views with the increase of the
  orbit inclination over time. Moreover, observations near perihelion,
  during the phase of lower rotational velocity of the solar surface
  relative to the spacecraft, allow longer-term studies of the off-limb
  coronal features, thus finally disentangling their intrinsic evolution
  from effects due to solar rotation. <BR /> Methods: Thanks to a novel
  occultation design and a combination of a UV interference coating of
  the mirrors and a spectral bandpass filter, Metis images the solar
  corona simultaneously in the visible light band, between 580 and 640
  nm, and in the UV H I Lyman-α line at 121.6 nm. The visible light
  channel also includes a broadband polarimeter able to observe the
  linearly polarised component of the K corona. The coronal images in
  both the UV H I Lyman-α and polarised visible light are obtained at
  high spatial resolution with a spatial scale down to about 2000 km
  and 15 000 km at perihelion, in the cases of the visible and UV light,
  respectively. A temporal resolution down to 1 s can be achieved when
  observing coronal fluctuations in visible light. <BR /> Results: The
  Metis measurements, obtained from different latitudes, will allow for
  complete characterisation of the main physical parameters and dynamics
  of the electron and neutral hydrogen/proton plasma components of the
  corona in the region where the solar wind undergoes the acceleration
  process and where the onset and initial propagation of coronal mass
  ejections (CMEs) take place. The near-Sun multi-wavelength coronal
  imaging performed with Metis, combined with the unique opportunities
  offered by the Solar Orbiter mission, can effectively address crucial
  issues of solar physics such as: the origin and heating/acceleration
  of the fast and slow solar wind streams; the origin, acceleration,
  and transport of the solar energetic particles; and the transient
  ejection of coronal mass and its evolution in the inner heliosphere,
  thus significantly improving our understanding of the region connecting
  the Sun to the heliosphere and of the processes generating and driving
  the solar wind and coronal mass ejections. <BR /> Conclusions: This
  paper presents the scientific objectives and requirements, the overall
  optical design of the Metis instrument, the thermo-mechanical design,
  and the processing and power unit; reports on the results of the
  campaigns dedicated to integration, alignment, and tests, and to
  the characterisation of the instrument performance; describes the
  operation concept, data handling, and software tools; and, finally,
  the diagnostic techniques to be applied to the data, as well as a brief
  description of the expected scientific products. The performance of the
  instrument measured during calibrations ensures that the scientific
  objectives of Metis can be pursued with success. <P />Metis website:
  <A href="http://metis.oato.inaf.it">http://metis.oato.inaf.it</A>

Title: Preface
Authors: Bemporad, A.; Criscuoli, S.; Del Moro, D.; Guglielmino,
   S. L.; Landi, S.; Laurenza, M.; Reale, F.; Straus, T.; Vecchio, A.
Bibcode: 2019NCimC..42....1B
Altcode:
  No abstract at ADS

Title: The third CO5BOLD workshop
Authors: Straus, T.; Marconi, M.; Alcalà, J. M.
Bibcode: 2017MmSAI..88....5S
Altcode:
  No abstract at ADS

Title: A virtual appliance as proxy pipeline for the Solar
    Orbiter/Metis coronagraph
Authors: Pancrazzi, M.; Straus, T.; Andretta, V.; Spadaro, D.; Haugan,
   S. V.; de Groof, A.; Carr, R.; Focardi, M.; Nicolini, G.; Landini,
   F.; Baccani, C.; Romoli, M.; Antonucci, E.
Bibcode: 2016SPIE.9913E..4LP
Altcode:
  Metis is the coronagraph on board Solar Orbiter, the ESA mission devoted
  to the study of the Sun that will be launched in October 2018. Metis is
  designed to perform imaging of the solar corona in the UV at 121.6 nm
  and in the visible range where it will accomplish polarimetry studies
  thanks to a variable retarder plate. Due to mission constraints, the
  telemetry downlink on the spacecraft will be limited and data will be
  downloaded with delays that could reach, in the worst case, several
  months. In order to have a quick overview on the ongoing operations
  and to check the safety of the 10 instruments on board, a high-priority
  downlink channel has been foreseen to download a restricted amount of
  data. These so-called Low Latency Data will be downloaded daily and,
  since they could trigger possible actions, they have to be quickly
  processed on ground as soon as they are delivered. To do so, a proper
  processing pipeline has to be developed by each instrument. This
  tool will then be integrated in a single system at the ESA Science
  Operation Center that will receive the downloaded data by the Mission
  Operation Center. This paper will provide a brief overview of the on
  board processing and data produced by Metis and it will describe the
  proxy-pipeline currently under development to deal with the Metis
  low-latency data.

Title: Testing Wave Propagation Properties in the Solar Chromosphere
    with ALMA and IRIS
Authors: Fleck, Bernard; Straus, Thomas; Wedemeyer, Sven
Bibcode: 2016SPD....47.0102F
Altcode:
  Waves and oscillations are interesting not only from the point of view
  that they can propagate energy into the chromosphere and dissipate that
  energy to produce non-radiative heating, they also carry information
  about the structure of the atmosphere in which they propagate. Since
  the late 80s there is substantial evidence that the chromospheric
  wave field is dominated by a non-propagating component, presumably
  resulting from wave reflection at the transition region. Observations
  of Doppler oscillations measured in the Ca II infrared tripet lines,
  Ca II K, and He 10830 all show vanishing phase lags (i.e. vanishing
  travel time differences) between the various lines, in particular also
  for frequencies above the cut-off frequency. Why is the apparent phase
  speed of high frequency acoustic waves in the chromosphere so high? Are
  these results misleading because of complex radiation transfer effects
  in these optically thick lines? ALMA, which acts as a linear thermometer
  of the solar chromosphere, will provide measurements of the local
  plasma conditions that should be, at least in principle, much easier
  to interpret. Multi-wavelength time series of ALMA observations of the
  temperature fluctuations of inter-network oscillations should allow
  travel time measurements between different heights as these disturbances
  propagate through the chromosphere and thus should finally settle the
  long-standing question about the propagation characteristics of high
  frequency acoustic waves in the chromosphere. We plan to combine ALMA
  mm-observations with high resolution IRIS observations in the Mg II
  h and k lines, and until ALMA observations are available, will study
  the expected signals using time series of mm-maps from 3D radiation
  hydrodynamics simulations that are being prepared within the framework
  of the Solar Simulations for the Atacama Large Millimeter Observatory
  Network (SSALMON).

Title: A steady-state supersonic downflow in the transition region
    above a sunspot umbra
Authors: Straus, Thomas; Fleck, Bernhard; Andretta, Vincenzo
Bibcode: 2015A&A...582A.116S
Altcode: 2015arXiv150704279S
  We investigate a small-scale (~1.5 Mm along the slit), supersonic
  downflow of about 90 km s<SUP>-1</SUP> in the transition region
  above the lightbridged sunspot umbra in AR 11836. The observations
  were obtained with the Interface Region Spectrograph (IRIS) on
  2013 September 2 from 16:40 to 17:59 UT. The downflow shows up as
  redshifted "satellite" lines of the Si iv and O iv transition region
  lines and is remarkably steady over the observing period of nearly
  80 min. The downflow is not visible in the chromospheric lines,
  which only show an intensity enhancement at the location of the
  downflow. The density inferred from the line ratio of the redshifted
  satellites of the O iv lines (N<SUB>e</SUB> = 10<SUP>10.6 ± 0.25</SUP>
  cm<SUP>-3</SUP>) is only a factor 2 smaller than the one inferred
  from the main components (N<SUB>e</SUB> = 10<SUP>10.95 ± 0.20</SUP>
  cm<SUP>-3</SUP>). Consequently, this implies a substantial mass flux
  (~5 × 10<SUP>-7</SUP> g cm<SUP>-2</SUP> s<SUP>-1</SUP>), which would
  evacuate the overlying corona on timescales close to 10 s. We interpret
  these findings as evidence of a stationary termination shock of a
  supersonic siphon flow in a cool loop that is rooted in the central
  umbra of the spot. <P />The movie is available in electronic form at <A
  href="http://www.aanda.org/10.1051/0004-6361/201525805/olm">http://www.aanda.org</A>

Title: Observations of a Steady-State Supersonic Downflow in the
    Transition Region above a Sunspot Umbra
Authors: Fleck, Bernhard; Straus, Thomas; Andretta, Vincenzo
Bibcode: 2015TESS....120311F
Altcode:
  Sunspots have been an area of intense research ever since Hale's
  discovery of strong magnetic fields in these structures. Here we report
  on the detection of a particular sunspot phenomenon: a small-scale (~
  1.5 Mm), supersonic downflow of about 90 km/s in the transition region
  above a light-bridged sunspot umbra. The observations were obtained with
  the Interface Imaging Region Spectrograph (IRIS) on 2 September 2013
  from 16:39 to 17:58 UT in the sunspot of AR 11836 near disk center. Slit
  length and width were 68” and 0.166”, respectively. The cadence of
  the time series was 3 s, with exposure times of 2 s. The observations
  comprise nine spectral windows: C II 1336, Fe XII 1349, Cl I 1352,
  O I 1356, Si IV 1394, Si IV 1403, NUV at 2786 and 2831, and Mg II h
  and k 2796. The spectral window containing the Si IV 1403 line also
  includes the O IV 1400, 1401, and 1405 lines, the last one blended
  with a S IV line. The downflow shows up as red-shifted, well-separated
  “satellite” lines of the Si IV and O IV transition region lines and
  is remarkably steady over the observing period of nearly 80 min. The
  satellite lines do not participate in the 3-min shock wave Doppler
  maneuvres of the main component. The downflow is not visible in the
  chromospheric lines, which only show an intensity enhancement at the
  location of the downflow. The density inferred from the line ratio of
  the redshifted satellites of the O IV lines (N<SUB>e</SUB>=10<SUP>10.5
  ±0.3 </SUP>cm<SUP>-3</SUP>) is only a factor 2.5 smaller than the
  one inferred from the main components (N<SUB>e</SUB>=10<SUP>10.9 ±0.2
  </SUP>cm<SUP>-3</SUP>). Consequently, this implies a substantial mass
  flux (~ 4×10<SUP>-7</SUP> g cm<SUP>-2</SUP> s<SUP>-1</SUP>), which
  would evacuate the overlying corona on time scales of the order of 10
  s. We interpret these findings as evidence of a stationary termination
  shock of a supersonic siphon flow in a cool loop rooted in the central
  umbra of the spot. Such stationary shocks have been predicted for
  siphon flows in hot coronal loops by Noci (1981).

Title: Wave Propagation in the Internetwork Chromosphere: Comparing
    IRIS Observations of Mg II h and k with Simulations
Authors: Fleck, B.; De Pontieu, B.; Leenaarts, J.; Pereira, T. M. D.;
   Straus, T.
Bibcode: 2014AGUFMSH51C4174F
Altcode:
  The objective of this study is to explore the dynamics of the
  upper internetwork chromosphere using high-resolution spectroscopic
  "sit-and-stare" time series obtained with the Interface Region Imaging
  Spectrogragh (IRIS) in the Mg II h and k lines. The Mg II h and k lines
  reveal a particularly complex spatio-temporal behavior, which strongly
  depends on the magnetic field topology. We focus on six parameters in
  both the h and k line: the Doppler shift and intensity of the central
  reversal (h3 and k3) and the blue and red emission peaks (h2v, h2r,
  k2v, k2r). In an effort to better understand what physical parameters
  can be extracted from these lines and to put our interpretation of
  the observations on more solid grounds, we extend our analysis to
  synthetic spectra obtained from numerical simulations and compare the
  results to the observations.

Title: On-board CME detection algorithm for the Solar Orbiter-METIS
    coronagraph
Authors: Bemporad, A.; Andretta, V.; Pancrazzi, M.; Focardi, M.;
   Straus, T.; Sasso, C.; Spadaro, D.; Uslenghi, M.; Antonucci, E.;
   Fineschi, S.; Abbo, L.; Nicolini, G.; Landini, F.; Romoli, M.; Naletto,
   G.; Nicolosi, P.
Bibcode: 2014SPIE.9152E..0KB
Altcode:
  The METIS coronagraph is one of the instruments part of the payload of
  the ESA - Solar Orbiter mission to be launched in 2017. The spacecraft
  will operate much like a planetary encounter mission, with the main
  scientific activity taking place with the remote-sensing instruments
  during three 10-days intervals per orbit: optimization of the different
  instrument observing modes will be crucial. One of the key scientific
  targets of METIS will be the study of transient ejections of mass
  through the solar corona (Coronal Mass Ejections - CMEs) and their
  heliospheric evolution. METIS will provide for the first time imaging of
  CMEs in two different wavelengths: VL (visible light 580- 640 nm) and UV
  (Lyman-α line of HI at 121.6 nm). The detection of transient phenomena
  shall be managed directly by the METIS Processing and Power Unit (MPPU)
  by means of both external triggers ("flags") coming from other Solar
  Orbiter instruments, and internal "flags" produced directly by the METIS
  on-board software. METIS on-board algorithm for the automatic detection
  of CMEs will be based on running differences between consecutive images
  re-binned to very low resolution and thresholded for significant changes
  over a minimum value. Given the small relative variation of white light
  intensity during CMEs, the algorithm will take advantage of VL images
  acquired with different polarization angles to maximize the detection
  capability: possible false detections should be automatically managed
  by the algorithm. The algorithm will be able to provide the CME first
  detection time, latitudinal direction of propagation on the plane
  of the sky (within 45 degrees), a binary flag indicating whether a
  "halo CME" has been detected.

Title: On-board detection and removal of cosmic ray and solar
    energetic particle signatures for the Solar Orbiter-METIS coronagraph
Authors: Andretta, V.; Bemporad, A.; Focardi, M.; Grimani, C.;
   Landini, F.; Pancrazzi, M.; Sasso, C.; Spadaro, D.; Straus, T.;
   Uslenghi, M. C.; Antonucci, E.; Fineschi, S.; Naletto, G.; Nicolini,
   G.; Nicolosi, P.; Romoli, M.
Bibcode: 2014SPIE.9152E..2QA
Altcode:
  METIS is part of the science payload of Solar Orbiter. It is a
  coronagraph designed to obtain images of the outer solar corona both in
  the visible 580-640 nm band and in the UV, in a narrow band centered
  around the hydrogen Lyman-α line. We describe the main features of
  the procedures to remove signatures due to cosmic rays (CRs) and to
  solar energetic particles (SEPs) comparing them with alternatives in
  other contexts and in other solar coronagraphic missions. Our analysis
  starts from a realistic assessment of the radiation environment where
  the instrument is expected to operate, which is characteristic of the
  interplanetary space of the inner solar system, but quite unusual for
  most solar missions.

Title: On the Signatures of Waves and Oscillations in IRIS
    Observations
Authors: Fleck, Bernard; Straus, Thomas; De Pontieu, Bart; Leenaarts,
   Jorrit; Pereira, Tiago M. D.
Bibcode: 2014AAS...22432305F
Altcode:
  The objective of this study is to explore the signatures of acoustic
  waves and oscillations in a variety of magnetic field configurations
  in the Sun’s atmosphere using high-resolution spectroscopic
  “sit-an-stare” time series obtained with the Interface Region
  Imaging Spectrogragh (IRIS) in lines formed in the chromosphere and
  lower transition region (C II 1335 &amp; 1336, C I 1352, O I 1356,
  Si IV 1394 &amp; 1403 and Mg h and k). The occurrence of oscillations
  in the transition region is found to strongly depend on the magnetic
  field topology. The Mg h and k lines reveal a particularly complex
  spatio-temporal behavior. In an effort to better understand what
  physical parameters can be extracted from these lines, we extend our
  analysis to synthetic spectra obtained from numerical simulations and
  compare the results to observations.

Title: The Intensity-Velocity Phase Spectra of Evanescent Oscillations
    and Acoustic Sources
Authors: Severino, G.; Straus, T.; Oliviero, M.; Steffen, M.; Fleck, B.
Bibcode: 2013SoPh..284..297S
Altcode: 2012SoPh..tmp..295S
  There are three major issues in modeling solar evanescent oscillations:
  the variation of the intensity [I]-velocity [V] phase difference of
  p-modes close to the base of photosphere; the existence of a plateau
  of negative I-V phase differences below and between the ridges of the
  low-frequency p-modes; the explanation of the I-V cross-spectra of
  the evanescent oscillations. We present new interpretations for the
  first two issues, based on modeling intensity fluctuations taking steep
  temperature gradients, opacity, and non-adiabatic cooling into account.

Title: On the Effects of the SDO Orbital Motion on the HMI Vector
    Magnetic Field Measurements
Authors: Fleck, B.; Centeno, R.; Cheung, M.; Couvidat, S.; Hayashi,
   K.; Rezaei, R.; Steiner, O.; Straus, T.
Bibcode: 2013enss.confE.145F
Altcode:
  In a previous study we have investigated the magnetic field diagnostics
  potential of SDO/HMI. We have used the output of high-resolution
  3D, time-dependent, radiative magneto-hydrodynamics simulations to
  calculate Stokes profiles for the Fe I 6173 Å line. From these we
  constructed Stokes filtergrams using a representative set of HMI filter
  response functions. The magnetic field vector (x,y) and line-of-sight
  Doppler velocities V(x,y) were determined from these filtergrams using
  a simplified version of the HMI magnetic field processing pipeline,
  and the reconstructed magnetic field (x,y) and line-of-sight velocity
  V(x,y) were compared to the actual magnetic field (x,y,z) and vertical
  velocity V0(x,y,z) in the simulations. The present investigation expands
  this analysis to include the effects of the significant orbital motions
  of SDO, which, given the limited wavelength range of the HMI filter
  profiles, affects the outer wing measurements and therefore might impact
  the magnetic field measurements. We find that the effects of the orbital
  movement of SDO are noticeable, in particular for the strongest fields
  (B &gt; 3 kG) and the maximum wavelength shift of 5.5 km/s (3.5 km/s
  orbital movement + 2 km/s solar rotation). Saturation effects for strong
  fields (B &gt; 3 kG) are already visible for wavelength shifts of 3.2
  km/s (orbital movement, disk center). The measurements of inclination
  and vertical velocity are more robust. Compared to other factors of
  uncertainty in the inversion of HMI Stokes measurements the orbital
  movement is not a major concern or source of error.

Title: Acoustic-Gravity Waves in the Solar Atmosphere: Comparing
    Hinode/SP Observations with Numerical Simulations
Authors: Fleck, Bernard; Straus, T.; Severino, G.
Bibcode: 2012AAS...22020121F
Altcode:
  We investigate the signatures of acoustic-gravity waves in Hinode/SP
  observations and compare them to those found in line spectra synthesized
  from high-resolution 3D radiation-hydrodynamics simulations. The
  Hinode/SP time series extends over 4 hours, with a cadence of 16 s and a
  spatial resolution of 0.16 arcsec/pixel. The observations are compared
  to two numerical simulations of the Sun’s surface layers, both
  computed with the radiation hydrodynamics code CO<SUP>5</SUP>BOLD. The
  higher resolution simulation has a fixed 3D Cartesian grid with 400
  x 400 x 300 cells, each of size 14 km x 14 km x 7.5 km, the lower
  resolution simulation 200 x 200 x 250 cells, each of size 56 km x 56
  km x 21 km. The higher resolution simulation thus covers a cube of 5.6
  x 5.6 x 2.3 Mm<SUP>3</SUP>, the lower resolution simulation a cube of
  size 11.2 x 11.2 x 5.2 Mm<SUP>3</SUP>. A line-synthesis code, based
  on the assumption of local thermodynamic equilibrium (LTE), was fed
  with the physical parameters of the simulations to produce synthetic,
  two-dimensional spectra of the photospheric lines of Fe 6301/6302 Å
  (Hinode/SP), Fe 6173 Å (SDO/ HMI), and Ni 6768 Å (SOHO/MDI). The
  resulting Doppler velocity time series are analyzed using Fourier
  techniques and compared to the observed Hinode/SP spectra. The
  height-dependent energy flux in the simulations is determined in the
  acoustic, evanescent and internal gravity wave regime and compared to
  energy flux estimates from the Hinode observations and the synthesized
  Doppler velocities of the simulations.

Title: On The Magnetic-Field Diagnostics Potential of SDO/HMI
Authors: Fleck, Bernard; Hayashi, K.; Rezaei, R.; Vitas, N.; Centeno,
   R.; Cheung, M.; Couvidat, S.; Fischer, C.; Steiner, O.; Straus, T.;
   Viticchie, B.
Bibcode: 2012AAS...22020701F
Altcode:
  The Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics
  Observatory (SDO) is designed to study oscillations and the magnetic
  field in the solar photosphere. It observes the full solar disk
  in the Fe I absorption line at 6173 Å. We use the output of three
  high-resolution 3D, time-dependent, radiative magneto-hydrodynamics
  simulations (two based on the MURaM code, one on the CO<SUP>5</SUP>BOLD
  code) to calculate Stokes profiles for the Fe I 6173 Å line
  for snapshots of a sunspot, a plage area and an enhanced network
  region. Stokes filtergrams are constructed for the 6 nominal HMI
  wavelengths by multiplying the Stokes profiles with a representative
  set of HMI filter response functions. The magnetic field vector B(x,y)
  and line-of-sight Doppler velocities V(x,y) are determined from these
  filtergrams using a simplified version of the HMI magnetic field
  processing pipeline. Finally, the reconstructed magnetic field B(x,y)
  and line-of-sight velocity V(x,y) are compared to the actual magnetic
  field B<SUB>0</SUB>(x,y,z) and vertical velocity V<SUB>0</SUB>(x,y,z)
  in the simulations.

Title: On the Magnetic-Field Diagnostics Potential of SDO/HMI
Authors: Fleck, B.; Hayashi, K.; Rezaei, R.; Vitas, N.; Centeno,
   R.; Cheung, M.; Couvidat, S.; Fischer, C.; Steiner, O.; Straus, T.;
   Viticchie, B.
Bibcode: 2012decs.confE.104F
Altcode:
  The Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics
  Observatory (SDO) is designed to study oscillations and the magnetic
  field in the solar photosphere. It observes the full solar disk
  in the Fe I absorption line at 6173 Å. We use the output of three
  high-resolution 3D, time-dependent, radiative magneto-hydrodynamics
  simulations (two based on the MURaM code, one on the CO5BOLD code)
  to calculate Stokes profiles Fi(λ,x,y; i=I, V, Q, U) for the Fe I
  6173 Å line for snapshots of a sunspot, a plage area and an enhanced
  network region. Stokes filtergrams are constructed for the 6 nominal
  HMI wavelengths by multiplying the Stokes profiles with a representative
  set of HMI filter response functions. The magnetic field vector B(x,y)
  and line-of-sight Doppler velocities V(x,y) are determined from these
  filtergrams using a simplified version of the HMI magnetic field
  processing pipeline. Finally, the reconstructed magnetic field B(x,y)
  and line-of-sight velocity V(x,y) are compared to the actual magnetic
  field B0(x,y,z) and vertical velocity V0(x,y,z) in the simulations.

Title: On the Magnetic-Field Diagnostics Potential of SDO/HMI
Authors: Fleck, B.; Hayashi, K.; Rezaei, R.; Vitas, N.; Centeno, R.;
   Couvidat, S.; Fischer, C.; Steiner, O.; Straus, T.; Viticchie, B.
Bibcode: 2011sdmi.confE..74F
Altcode:
  The Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics
  Observatory (SDO) is designed to study oscillations and the magnetic
  field in the solar photosphere. It observes the full solar disk in the
  Fe I 6173 absorption line. We use the output of two high-resolution 3D,
  time-dependent, radiative magneto-hydrodynamics simulations (one based
  on the MURAM code, the other one on the COBOLD code) to calculate
  Stokes profiles for the Fe I 6173 line for a snapshot of a plage
  region and a snapshot of an enhanced network region. After spatially
  degrading the Stokes profiles to HMI resolution, they are multiplied
  by a representative set of HMI filter response functions and Stokes
  filtergrams are constructed for the 6 nominal HMI wavelengths. The
  magnetic field vector and line-of-sight Doppler velocities are
  determined from these filtergrams using a simplified version of the HMI
  magnetic field processing pipeline. Finally, the reconstructed magnetic
  field is compared to the actual magnetic field in the simulation.

Title: On the Formation Height of the SDO/HMI Fe 6173 Å Doppler
    Signal
Authors: Fleck, B.; Couvidat, S.; Straus, T.
Bibcode: 2011SoPh..271...27F
Altcode: 2011SoPh..tmp..242F; 2011arXiv1104.5166F; 2011SoPh..tmp..117F;
   2011SoPh..tmp..173F
  The Helioseismic and Magnetic Imager (HMI) onboard the Solar
  Dynamics Observatory (SDO) is designed to study oscillations and the
  magnetic field in the solar photosphere. It observes the full solar
  disk in the Fe I absorption line at 6173 Å. We use the output of a
  high-resolution, 3D, time-dependent, radiation-hydrodynamic simulation
  based on the CO<SUP>5</SUP>BOLD code to calculate profiles F(λ,x,y,t)
  for the Fe I 6173 Å line. The emerging profiles F(λ,x,y,t) are
  multiplied by a representative set of HMI filter-transmission profiles
  R<SUB>i</SUB>(λ, 1≤i≤6) and filtergrams I<SUB>i</SUB>(x,y,t;
  1≤i≤6) are constructed for six wavelengths. Doppler velocities
  V<SUB>HMI</SUB>(x,y,t) are determined from these filtergrams using
  a simplified version of the HMI pipeline. The Doppler velocities are
  correlated with the original velocities in the simulated atmosphere. The
  cross-correlation peaks near 100 km, suggesting that the HMI Doppler
  velocity signal is formed rather low in the solar atmosphere. The same
  analysis is performed for the SOHO/MDI Ni I line at 6768 Å. The MDI
  Doppler signal is formed slightly higher at around 125 km. Taking
  into account the limited spatial resolution of the instruments,
  the apparent formation height of both the HMI and MDI Doppler signal
  increases by 40 to 50 km. We also study how uncertainties in the HMI
  filter-transmission profiles affect the calculated velocities.

Title: High-frequency Waves in Numerical Simulations of the Solar
    Atmosphere
Authors: Fleck, Bernard; Straus, T.; Severino, G.
Bibcode: 2011SPD....42.1720F
Altcode: 2011BAAS..43S.1720F
  We investigate the excitation processes, propagation characteristics,
  and energy transport of high-frequency waves in the solar atmosphere
  with the help of high-resolution 3D radiation-hydrodynamics
  simulations. Time series of synthetic spectra of four photospheric
  Fraunhofer lines (Fe 6302, Fe 6301, Fe 6173, Ni 6768) from these
  simulations are analyzed in order to evaluate the diagnostic power of
  spectroscopic observations.

Title: Estimating the Energy Flux of Acoustic-Gravity Waves in the
    Solar Atmosphere from SDO/HMI Data
Authors: Fleck, B.; Straus, T.; Jefferies, S.; Scherrer, P.
Bibcode: 2010AGUFMSH11A1602F
Altcode:
  Straus et al. (2008, 2009) demonstrated the existence of internal
  gravity waves in the solar atmosphere and showed that they are a
  key mediator of mechanical energy in the middle/upper photosphere,
  transporting even more energy than high-frequency acoustic waves. Here
  we repeat this analysis with data from SDO/HMI, which offers several
  distinct advantages, which are particularly relevant for the study
  of internal gravity waves (which have long periods and small spatial
  scales): excellent image stability over long time intervals, high
  spatial resolution, large field-of-view, and good temporal cadence.

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: 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 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: 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: 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: Spatio-Temporal Analysis of Photospheric Turbulent Velocity
    Fields Using the Proper Orthogonal Decomposition
Authors: Vecchio, A.; Carbone, V.; Lepreti, F.; Primavera, L.;
   Sorriso-Valvo, L.; Straus, T.; Veltri, P.
Bibcode: 2008SoPh..251..163V
Altcode: 2008SoPh..tmp...40V
  The spatio-temporal dynamics of the solar photosphere are studied by
  performing a proper orthogonal decomposition (POD) of line-of-sight
  velocity fields computed from high-resolution data coming from the
  SOHO/MDI instrument. Using this technique, we are able to identify and
  characterize the different dynamical regimes acting in the system. All
  of the POD modes are characterized by two well-separated peaks in the
  frequency spectra. In particular, low-frequency oscillations, with
  frequencies in the range 20 - 130 μHz, dominate the most energetic
  POD modes (excluding solar rotation) and are characterized by spatial
  patterns with typical scales of about 3 Mm. Patterns with larger
  typical scales, of about 10 Mm, are dominated by p-mode oscillations
  at frequencies of about 3000 μHz. The p-mode properties found by
  POD are in agreement with those obtained with the classical Fourier
  analysis. The spatial properties of high-energy POD modes suggest
  the presence of a strong coupling between low-frequency modes and
  turbulent convection.

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: Velocity and Intensity Power and Cross Spectra in Numerical
    Simulations of Solar Convection
Authors: Severino, G.; Straus, T.; Steffen, M.
Bibcode: 2008SoPh..251..549S
Altcode: 2008SoPh..tmp...54S
  Fitting observed power and cross spectra of medium-degree p modes
  in velocity (V) and intensity (I) has been widely used for getting
  information about the p-mode excitation process and, in particular,
  for trying to determine the type and location of the acoustic
  sources. Numerical simulations of solar convection allow one to
  "observe" velocity and temperature (T, used as proxy for I) fluctuations
  in different reference frames. Sampling the oscillations on planes of
  constant optical depth (τ-frame) closely corresponds to the observer's
  point of view, whereas sampling the oscillations at constant geometrical
  height (z-frame) is more appropriate for comparison with predictions
  from theoretical models based on Eulerian hydrodynamics. The results of
  the analysis in the two frames show significant differences. Considering
  the effects introduced on oscillations by the steep temperature gradient
  of the photosphere and by the temperature- and pressure-dependent
  continuum opacity, we develop a new model for fitting the simulated V
  and T power and cross spectra both in the τ- and z-frames and discuss
  its merits and limitations.

Title: The Energy Flux of Internal Gravity Waves in the Lower Solar
    Atmosphere
Authors: Straus, Thomas; Fleck, Bernhard; Jefferies, Stuart M.;
   Cauzzi, Gianna; McIntosh, Scott W.; Reardon, Kevin; Severino, Giuseppe;
   Steffen, Matthias
Bibcode: 2008ApJ...681L.125S
Altcode:
  Stably stratified fluids, such as stellar and planetary atmospheres,
  can support and propagate gravity waves. On Earth these waves,
  which can transport energy and momentum over large distances and can
  trigger convection, contribute to the formation of our weather and
  global climate. Gravity waves also play a pivotal role in planetary
  sciences and modern stellar physics. They have also been proposed
  as an agent for the heating of stellar atmospheres and coronae, the
  exact mechanism behind which is one of the outstanding puzzles in solar
  and stellar physics. Using a combination of high-quality observations
  and 3D numerical simulations we have the first unambiguous detection
  of propagating gravity waves in the Sun's (and hence a stellar)
  atmosphere. Moreover, we are able to determine the height dependence of
  their energy flux and find that at the base of the Sun's chromosphere it
  is around 5 kW m<SUP>-2</SUP>. This amount of energy is comparable to
  the radiative losses of the entire chromosphere and points to internal
  gravity waves as a key mediator of energy into the solar atmosphere.

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: Internal Gravity Waves and their Role in the Energetics of
    the Solar Atmosphere
Authors: Fleck, Bernard; Straus, T.; Jefferies, S.; McIntosh, S. W.;
   Severino, G.; Steffen, M.
Bibcode: 2007AAS...210.2410F
Altcode: 2007BAAS...39..130F
  Internal gravity waves are believed to be excited by convective
  overshoot in the solar atmosphere. We compare the results from numerical
  simulations of the overshoot region of compressible convection into a
  stable photosphere, with observations of the velocity field at several
  heights in the solar atmosphere. We find a consistent picture for the
  quiet middle/upper photosphere in which internal gravity waves are the
  dominant phenomenon at low frequencies (&lt; 2.5 mHz). We estimate the
  contribution of these waves to the energy balance in the photosphere
  and low chromosphere.

Title: Resonant Oscillation Modes and Background in Realistic
    Hydrodynamical Simulations of Solar Surface Convection
Authors: Straus, T.; Severino, G.; Steffen, M.
Bibcode: 2006ESASP.617E...4S
Altcode: 2006soho...17E...4S
  No abstract at ADS

Title: SOLARNET-Italian Solar Archive Federation. The First Italian
    Virtual Observatory Application
Authors: Volpicelli, C. A.; Antonucci, E.; Cora, A.; Giordano, S.;
   Messerotti, M.; Santin, A.; Zlobec, P.; Severino, G.; Oliviero, M.;
   DeMarino, I.; Alvino, R.; Straus, T.; Ermolli, I.; Centrone, C.;
   Perna, C.; Zuccarello, F.; Romano, P.; Spadaro, D.; Contarino, L.
Bibcode: 2006MSAIS...9..129V
Altcode:
  We describe the implementation of the national project SOLARNET (SOLar
  ARchive NETwork) aimed at federating the heterogeneous Italian solar
  data archives into a VO (Virtual Observatory) framework as a single
  integrated database, and providing users with tools to search and
  retrieve specific data sets. It interoperates using the SOAP/XML
  Web Services exposed by each single node and managed via a unified
  Portal.This project is the first real Italian Virtual Observatory
  application using the standard defined by the IVOA (International
  Virtual Observatory Alliance) working groups.

Title: A model of intensity and velocity power and I-V phase
    difference across p-mode line profile based on a forced damped
    harmonic oscillator and on the observed coherence spectrum
Authors: Magri, Maria; Oliviero, Maurizio; Severino, Giuseppe;
   Straus, Thomas
Bibcode: 2001MmSAI..72..511M
Altcode:
  We develop a simple model, based on a damped harmonic oscillator excited
  by a random forcing, with the aim to reproduce the observed trends in
  the intensity I and velocity V power and in the I-V phase difference and
  coherence spectra. The model accounts for an oscillation mode embedded
  in a solar background which is partly correlated to the mode. The
  complex vectors I and V and the corresponding power spectra and I-V
  phase difference are computed. The observed power spectra and the I-V
  phase difference in the frequencies range 2.245 - 2.275 mHz for l = 17
  (GONG data) are used as a comparison. We can also reproduce the trend
  of the observed coherence. The obtained results are quite stimulating to
  understand how the correlated convective background affects the data and
  what fraction of the convective background is correlated to the mode.

Title: Recent results on the solar photospheric dynamics
Authors: Severino, Giuseppe; Magri, Maria; Oliviero, Maurizio;
   Straus, Thomas
Bibcode: 2001MmSAI..72..677S
Altcode:
  The solar photosphere is a relatively small atmospheric layer, that
  is a boundary between the convective interior and the optically thin
  and magnetic outer atmosphere, where convection overshoots into and
  different types of waves are excited and damped. Such a system cannot
  be described by a simple dynamical model. Recent progress in the study
  of the solar photospheric dynamics has been obtained thanks to the
  space-time analysis of the velocity (V) and intensity (I) fluctuations
  measured by the GONG, MDI/SOHO and VAMOS experiments. In particular,
  it is claimed that the I-V phase differences and coherence can allow
  to identify the seismic events which are thought to excite the solar
  global oscillations.

Title: The photosphere - region of reflection and excitation of
    solar oscillations
Authors: Straus, Thomas; Severino, Giuseppe
Bibcode: 2001MmSAI..72..533S
Altcode:
  Two observational facts have enforced the interest in the solar p-mode
  background spectrum in the recent past: the opposite asymmetry of the
  p-mode profiles in intensity and velocity, and the particular behavior
  of the I-V phase difference in the transition from the background to
  the p-mode across the line profiles. We give a short review on the
  current status of the investigation of the solar background.

Title: I-V phase difference and gain analysis of GONG full-disk data
Authors: Oliviero, M.; Severino, G.; Straus, T.; Jefferies, S. M.;
   Appourchaux, T.
Bibcode: 2000MmSAI..71..999O
Altcode:
  No abstract at ADS

Title: Calibration of VAMOS Magnetic Data
Authors: Vogt, E.; Oliviero, M.; Severino, G.; Straus, T.
Bibcode: 1999ESASP.448..405V
Altcode: 1999ESPM....9..405V; 1999mfsp.conf..405V
  No abstract at ADS

Title: Wavelet Analysis of Spatial Coherent Structures in the
    Photosphere
Authors: Pietropaolo, E.; Berrilli, F.; Consolini, G.; Smaldone,
   L. A.; Straus, T.; Cauzzi, G.; Bruno, R.; Bavassano, B.
Bibcode: 1999ESASP.448..343P
Altcode: 1999ESPM....9..343P; 1999mfsp.conf..343P
  No abstract at ADS

Title: Properties of solar granulation cells in quiet regions as
    derived from a time series of white light images
Authors: Cauzzi, G.; Consolini, G.; Berrilli, F.; Smaldone, L. A.;
   Straus, T.; Bavassano, B.; Bruno, R.; Caccin, B.; Carbone, V.; Egidi,
   A.; Ermolli, I.; Florio, A.; Pietropaolo, E.
Bibcode: 1998MmSAI..69..647C
Altcode:
  No abstract at ADS

Title: The Magneto-Optical Filter in Napoli: Perspectives and Test
    Observations
Authors: Moretti, P. F.; Severino, G.; Cauzzi, G.; Reardon, K.;
   Straus, T.; Cacciani, A.; Marmolino, C.; Oliviero, M.; Smaldone, L. A.
Bibcode: 1997ASSL..225..293M
Altcode: 1997scor.proc..293M
  An observing station based on the Magneto-Optical-Filter (MOF)
  technology is being installed at Osservatorio Astronomico di
  Capodimonte, in Napoli. In this paper, the main characteristics and
  goals of this new instrument are discussed, and several velocity and
  magnetic observations from a test campaign are shown.

Title: Dynamics of the solar photosphere. I. Two-dimensional
    spectroscopy of mesoscale phenomena.
Authors: Straus, T.; Bonaccini, D.
Bibcode: 1997A&A...324..704S
Altcode:
  We address the "mesogranulation" phenomenon by analyzing a spectral
  time series, taken at disk center with a two-dimensional spectroscopy
  device and covering a period of 4 hours. This tunable device was
  composed by a Fabry-Perot interferometer mounted in tandem with an
  Universal Birefringent Filter (UBF). We calculate spatial power spectra,
  spatio-temporal k-ω power, phase difference and coherence spectra at
  different low photospheric levels, in order to investigate the nature
  of the mesoscale phenomena. At the lowest levels, mesostructures
  appear as a part of an extended distribution of granular sizes
  without further distinction from granulation. Here, the plasma
  flows are driven by convection. On the other hand, a different
  mesoscale phenomenon emerges at levels as high as approximately
  200-300km above τ_5000_=1, at medium spatial (k=~0.5...2Mm^-1^)
  and medium temporal (ν=~0.5...1mHz) frequencies. This phenomenon is
  distinct from convection by its non-convective phase difference values
  ({PHI}_v-I_=~-30°, {PHI}_v-v_&lt;0°) and by its different propagation
  character (almost horizontal propagation). By these properties, the
  mesoscale phenomena in the higher photosphere can be identified as
  internal gravity waves in the solar atmosphere.

Title: ARTHEMIS: The Archive Project for the IPM and THEMIS
Authors: Reardon, K.; Severino, G.; Cauzzi, G.; Gomez, M. T.; Straus,
   T.; Russo, G.; Smaldone, G.; Marmolino, C.
Bibcode: 1997ASPC..118..398R
Altcode: 1997fasp.conf..398R
  We describe the plan for ARTHEMIS, the italian archive for THEMIS, from
  the point of view of the prospective users of the archive. This archive
  is designed to store the data from the Italian Panoramic Monochromator
  (IPM) instrument installed on THEMIS as well as the full-disk images
  obtained by the telescope. We break the expected users down into
  seven categories: a) prospective IPM users; b) campaign planners; c)
  data analysts, d) external collaborators; e) instrument monitors, f)
  archival observers; and g) the general public.

Title: ARTHEMIS: The archive project for the Italian Panoramic
    Monochromator
Authors: Reardon, K.; Severino, G.; Cauzzi, G.; Gomez, M. T.; Straus,
   T.; Russo, G.; Smaldone, L. A.; Marmolino, C.
Bibcode: 1997MmSAI..68..499R
Altcode:
  No abstract at ADS

Title: k-ω diagrams of the solar atmosphere revisited.
Authors: Deubner, F. -L.; Fleck, B.; Schmitz, F.; Straus, T.
Bibcode: 1990AGAb....5...35D
Altcode:
  No abstract at ADS

Title: Dynamics of mesogranulation.
Authors: Straus, T.; Deubner, F. -L.
Bibcode: 1990AGAb....5...34S
Altcode:
  No abstract at ADS

