Author name code: rybak
ADS astronomy entries on 2022-09-14
author:"Rybak, J." 
------------------------------------------------------------------------  

Title: The SLED project and the dynamics of coronal flux ropes
Authors: Malherbe, Jean-Marie; Mein, Pierre; Sayède, Frédéric;
   Rudawy, Pawel; Phillips, Kenneth; Keenan, Francis; Rybák, Jan
Bibcode: 2022AdSpR..70.1562M
Altcode:
  Investigations of the dynamics of the hot coronal plasma are crucial
  for understanding various space weather phenomena and making in-depth
  analyzes of the global heating of the solar corona. We present here
  numerical simulations of observations of siphon flows along loops
  (simple semi-circular flux ropes) to demonstrate the capabilities of
  the Solar Line Emission Dopplerometer (SLED), a new instrument under
  construction for imaging spectroscopy. It is based on the Multi-channel
  Subtractive Double Pass (MSDP) technique, which combines the advantages
  of filters and slit spectrographs. SLED will observe coronal structures
  in the forbidden lines of FeX 6374 Å and FeXIV 5303 Å, and will
  measure Doppler shifts up to 150 km s<SUP>-1</SUP> at high precision
  (50 m s<SUP>-1</SUP>) and cadence (1 Hz). It is optimized for studies
  of the dynamics of fast evolving events such as flares or Coronal
  Mass Ejections (CMEs), as well as for the detection of high-frequency
  waves. Observations will be performed with the coronagraph at Lomnický
  Štít Observatory (LSO), and will also occur during total solar
  eclipses as SLED is a portable instrument.

Title: Narrowband Spikes Observed During the 13 June 2012 Flare in
    the 800 - 2000 MHz Range
Authors: Karlický, Marian; Rybák, Ján; Benáček, Jan; Kašparová,
   Jana
Bibcode: 2022SoPh..297...54K
Altcode: 2022arXiv220409327K
  Narrowband (∼5 MHz) and short-lived (∼0.01 s) spikes with three
  different distributions in the 800 - 2000 MHz radio spectrum of the
  13 June 2012 flare are detected and analyzed. We designate them as SB
  (spikes distributed in a broad band or bands), SZ (spikes distributed
  in zebra-like bands) and SBN (spikes distributed in broad and narrow
  bands). On analyzing AIA/SDO images of the active region NOAA 11504,
  a rough correspondence between groups of the spikes observed at 1000
  MHz and peaks in the time profiles of AIA channels taken from the
  flare subarea close to the leading sunspot is found. Among the types
  of spikes the SZ type is the most interesting because it resembles
  zebras. Therefore, using autocorrelation and crosscorrelation methods
  we compare SZ and SBN spikes with the typical zebra observed in the
  same frequency range. While the ratio of SZ band frequencies with their
  frequency separation (220 MHz) is about 4, 5, and 6, in the zebra the
  frequency stripe separation is about 24 MHz and the ratio is around
  50. Moreover, the bandwidth of SZ bands, which consists of clouds of
  narrowband spikes, is much broader than that of zebra stripes. This
  comparison indicates that SZ spikes are generated in a different way
  from the zebra, but in a similar way to SBN spikes. We successfully fit
  the SZ band frequencies by the Bernstein modes. Based on this fitting
  we interpret SZ and SBN spikes as those generated in the model of
  Bernstein modes. Thus, the magnetic field and plasma density in the SZ
  spike source are estimated to be about 79 G and 8.4 × 10<SUP>9</SUP>
  cm<SUP>−3</SUP>, respectively.

Title: The Solar Line Emission Dopplerometer project
Authors: Malherbe, Jean-Marie; Mein, Pierre; Sayède, Frédéric;
   Rudawy, Pawel; Phillips, Kenneth; Keenan, Francis; Rybák, Jan
Bibcode: 2022ExA....53...83M
Altcode: 2021ExA...tmp..125M; 2021arXiv211001645M
  Observations of the dynamics of solar coronal structures are necessary
  to investigate space weather phenomena and global heating of the
  corona. The profiles of high temperature lines emitted by the hot plasma
  are usually integrated by narrow band filters or recorded by classical
  spectroscopy. We present in this paper details of a new transportable
  instrument (under construction) for imaging spectroscopy: the Solar Line
  Emission Dopplerometer (SLED). It uses the Multi-channel Subtractive
  Double Pass (MSDP) technique, which combines the advantages of both
  filters and narrow slit spectrographs, i.e. high temporal, spatial and
  spectral resolutions. The SLED will measure at high cadence (1 Hz)
  the line-of-sight velocities (Doppler shifts) of hot coronal loops,
  in the forbidden lines of FeX 6374 Å and FeXIV 5303 Å. It will
  follow the dynamics of fast evolving events of solar activity such
  as flares or Coronal Mass Ejections (CMEs), and also study coronal
  heating by short period waves. Observations will be performed with
  the coronagraph at the Lomnický Štít Observatory (LSO, in Slovakia)
  or during total eclipses. The SLED will also observe the dynamics of
  solar prominences in Hα 6563 Å or He D3 5876 Å lines when mounted
  on the Białków coronagraph (near Wrocław, Poland). It is fully
  compatible with polarimetric measurements by various techniques.

Title: Narrowband Spikes Observed during the 2013 November 7 Flare
Authors: Karlický, Marian; Benáček, Jan; Rybák, Ján
Bibcode: 2021ApJ...910..108K
Altcode: 2021arXiv210401345K
  Narrowband spikes have been observed in solar flares for several
  decades. However, their exact origin is still discussed. To contribute
  to understanding of these spikes, we analyze the narrowband spikes
  observed in the 800-2000 MHz range during the impulsive phase of the
  2013 November 7 flare. In the radio spectrum, the spikes started with
  typical broadband clouds of spikes, and then their distribution in
  frequencies changed into unique, very narrow bands having noninteger
  frequency ratios. We successfully fitted frequencies of these narrow
  spike bands by those, calculating dispersion branches and growth rates
  of the Bernstein modes. For comparison, we also analyzed the model
  where the narrow bands of spikes are generated at the upper-hybrid
  frequencies. Using both models, we estimated the plasma density and
  magnetic field in spike sources. Then, the models are discussed,
  and arguments in favor of the model with the Bernstein modes are
  presented. Analyzing frequency profiles of this spike event by the
  Fourier method, we found the power-law spectra with the power-law
  indices varying in the -0.8 to -2.75 interval. Because at some times
  this power-law index was close to the Kolmogorov spectral index (-5/3),
  we propose that the spikes are generated through the Bernstein modes
  in turbulent plasma reconnection outflows or directly in the turbulent
  magnetic reconnection of solar flares.

Title: Electron Densities in the Solar Corona Measured Simultaneously
    in the Extreme Ultraviolet and Infrared
Authors: Dudík, Jaroslav; Del Zanna, Giulio; Rybák, Ján;
   Lörinčík, Juraj; Dzifčáková, Elena; Mason, Helen E.; Tomczyk,
   Steven; Galloy, Michael
Bibcode: 2021ApJ...906..118D
Altcode: 2020arXiv201109175D
  Accurate measurements of electron density are critical for
  determination of the plasma properties in the solar corona. We compare
  the electron densities diagnosed from Fe XIII lines observed by the
  Extreme-Ultraviolet Imaging Spectrometer (EIS) onboard the Hinode
  mission with the near-infrared (NIR) measurements provided by the
  ground-based Coronal Multichannel Polarimeter (CoMP). To do that, the
  emissivity-ratio method based on all available observed lines of Fe
  XIII is used for both EIS and CoMP. The EIS diagnostics is further
  supplemented by the results from Fe XII lines. We find excellent
  agreement, within 10%, between the electron densities measured from both
  extreme-ultraviolet and NIR lines. In the five regions selected for
  detailed analysis, we obtain electron densities of log(N<SUB>e</SUB>
  [cm<SUP>-3</SUP>]) = 8.2-8.6. Where available, the background
  subtraction has a significant impact on the diagnostics, especially on
  the NIR lines, where the loop contributes less than a quarter of the
  intensity measured along the line of sight. For the NIR lines, we find
  that the line center intensities are not affected by stray light within
  the instrument, and recommend using these for density diagnostics. The
  measurements of the Fe XIII NIR lines represent a viable method for
  density diagnostics using ground-based instrumentation.

Title: The 2017 September 6 Flare: Radio Bursts and Pulsations in
    the 22-5000 MHz Range and Associated Phenomena
Authors: Karlický, Marian; Rybák, Ján
Bibcode: 2020ApJS..250...31K
Altcode: 2020arXiv200905756K
  For the 2017 September 6 flare (SOL2017-Sep-06T11:53) we present not
  only unusual radio bursts but also their interesting time association
  with the other flare phenomena observed in extreme ultraviolet (EUV),
  white-light, X-ray, and γ-ray emissions. Using our new method based on
  wavelets we found quasi-periodic pulsations (QPPs) in several locations
  of the whole time-frequency domain of the analyzed radio spectrum
  (11:55-12:07 UT and 22-5000 MHz). Among them the drifting QPPs are
  new and the most interesting, especially a bidirectional QPP at the
  time of the hard X-ray and γ-ray peaks and a sunquake start. In the
  pre-impulsive phase we show an unusual drifting pulsation structure
  (DPS) in association with the EUV brightenings caused by the interaction
  of magnetic ropes. In the flare impulsive phase we found an exceptional
  radio burst drifting from 5000 to 800 MHz. In connection with this
  drifting burst, we show a U burst at about the onset time of an EUV
  writhed structure and a drifting radio burst as a signature of a shock
  wave at high frequencies (1050-1350 MHz). In the peak flare phase we
  found an indication of an additional energy-release process located
  at higher altitudes in the solar atmosphere. These phenomena are
  interpreted considering a rising magnetic rope, magnetosonic waves,
  and particle beams. Using a density model we estimated the density,
  wave velocities, and source heights for the bidirectionally drifting
  QPPs, the density for the pre-impulsive DPS and U burst, and the
  density and magnetic field strength for the drifting radio burst.

Title: Drifting Pulsation Structure at the Very Beginning of the
    2017 September 10 Limb Flare
Authors: Karlický, Marian; Chen, Bin; Gary, Dale E.; Kašparová,
   Jana; Rybák, Jan
Bibcode: 2020ApJ...889...72K
Altcode: 2019arXiv191212518K
  Drifting pulsation structures (DPSs) are important radio fine structures
  usually observed at the beginning of eruptive solar flares. It has been
  suggested that DPSs carry important information on the energy release
  processes in solar flares. We study DPS observed in an X8.2-class flare
  on 2017 September 10 in the context of spatial and spectral diagnostics
  provided by microwave, EUV, and X-ray observations. We describe DPS
  and its substructures that were observed for the first time. We use a
  new wavelet technique to reveal characteristic periods in DPS and their
  frequency bands. Comparing the periods of pulsations found in this DPS
  with those in previous DPSs, we found new very short periods in the
  0.09-0.15 s range. We present Expanded Owens Valley Solar Array images
  and spectra of microwave sources observed during the DPS. This DPS at
  its very beginning has pulsations in two frequency bands (1000-1300 MHz
  and 1600-1800 MHz), which are interconnected by fast drifting bursts. We
  show that these double-band pulsations started just at the moment when
  the ejected filament splits apart in a tearing motion at the location
  where a signature of the flare current sheet later appeared. Using the
  standard flare model and previous observations of DPSs, we interpret
  these double-band pulsations as a radio signature of superthermal
  electrons trapped in the rising magnetic rope and flare arcade at the
  moment when the flare magnetic reconnection starts. The results are
  discussed in a scenario with the plasmoid in the rising magnetic rope.

Title: Coordinated observations between China and Europe to follow
    active region 12709
Authors: González Manrique, S. J.; Kuckein, C.; Gömöry, P.; Yuan,
   S.; Xu, Z.; Rybák, J.; Balthasar, H.; Schwartz, P.
Bibcode: 2020IAUS..354...58G
Altcode: 2020IAUS..354...58M; 2019arXiv191208611G
  We present the first images of a coordinated campaign to follow active
  region NOAA 12709 on 2018 May 13 as part of a joint effort between
  three observatories (China-Europe). The active region was close to
  disk center and enclosed a small pore, a tight polarity inversion line
  and a filament in the chromosphere. The active region was observed
  with the 1.5-meter GREGOR solar telescope on Tenerife (Spain) with
  spectropolarimetry using GRIS in the He i 10830 Å spectral range
  and with HiFI using two broad-band filter channels. In addition,
  the Lomnicky Stit Observatory (LSO, Slovakia) recorded the same
  active region with the new Solar Chromospheric Detector (SCD) in
  spectroscopic mode at Hα 6562 Å. The third ground-based telescope
  was located at the Fuxian Solar Observatory (China), where the active
  region was observed with the 1-meter New Vacuum Solar Telescope
  (NVST), using the Multi-Channel High Resolution Imaging System at
  Hα 6562 Å. Overlapping images of the active region from all three
  telescopes will be shown as well as preliminary Doppler line-of-sight
  (LOS) velocities. The potential of such observations are discussed.

Title: Automatic detection and tracking of coronal bright points in
    SDO/AIA images
Authors: Dorotovic, I.; Coelho, A.; Rybak, J.; Mora, A.; Ribeiro,
   R.; Kusa, W.; Pires, R.
Bibcode: 2018SunGe..13..129D
Altcode:
  The AIA instrument, on-board the SDO satellite, provides high-resolution
  and high-cadence solar images since 2010. To extract scientific
  knowledge about coronal bright points (CBPs) from those high-resolution
  images there is a need for efficient automatic algorithms to detect
  and/or track the CBPs. In the last decade other research teams
  have developed algorithms to obtain more precise estimations of
  the solar rotation profile. However, it is a difficult task because
  CBPs may change shape and size over time, yielding great difficulty
  to track them. In this work we discuss the usage of two automatic
  segmentation algorithms to detect CBPs in SDO/AIA images: (1) using
  SunPy and OpenCV in Python and (2) using a Gradient Path Labeling
  (GPL) algorithm. Our preliminary tests and results, with a three-day
  dataset, show that these algorithms are promising tools to help refine
  the solar rotational profile

Title: Fourier Power Spectra of Solar Noise Storms
Authors: Karlický, Marian; Rybák, Ján; Monstein, Christian
Bibcode: 2018SoPh..293..143K
Altcode:
  We analyzed three noise storms recorded on 200 - 400 MHz Trieste
  Callisto radio spectra on 2 July 2012, 8 July 2012, and 16 July 2012
  by the Fourier method. We divided intervals of the noise storms into
  five-minute intervals, and in these intervals we computed the mean
  Fourier spectra as a function of the wave numbers in the frequency
  and height-scale spaces. We found that these Fourier spectra, where
  the spectrum from the quiet-activity interval was subtracted, are
  power-law spectra. The mean power-law index of these spectra in the
  range ln(k<SUB>z</SUB>)=[1.8 ,2.9 ] (where k<SUB>z</SUB> is the wave
  number in the height-scale space) is −1.7 ±0.14 , −1.6 ±0.14 ,
  and −1.5 ±0.12 for the 2 July 2012, the 8 July 2012, and the 16
  July 2012 noise storms, respectively. It appears that as the number of
  Type-I bursts in the studied interval increases, the power-law index
  becomes closer to −5 /3 ; this is known as the Kolmogorov spectral
  index. The power-law index of the noise storms is very similar to that
  of the narrowband dm-spikes found in our previous studies. Furthermore,
  we found a break in the power spectra at ln(k<SUB>z</SUB>)≈2.9 , and
  the mean power-law index values above this break are −2.9 ±0.46 ,
  −3.1 ±0.65 , and −3.4 ±0.98 , respectively.

Title: Gradient Path Labelling method and tracking method for
    calculation of solar differential rotation using coronal bright points
Authors: Dorotovič, I.; Coelho, A.; Rybák, J.; Mora, A.; Ribeiro, R.
Bibcode: 2018A&C....25..168D
Altcode:
  With new space missions, such as Solar Dynamics Observatory (SDO),
  solar images are being produced in unprecedented volumes. To derive,
  as much as possible, information on evolution of solar activity from
  those huge datasets, the scientific community needs a new generation
  of software tools for automatic and efficient data processing. In the
  last decade, several research teams have been developing tools for
  obtaining more precise estimations of the solar rotation profile,
  but more are needed to improve knowledge about solar activity. We
  applied here a segmentation algorithm called Gradient Path Labelling
  (GPL), used originally to identify drusens in medical retinal images,
  to detect and track the coronal bright points (CBPs) using images
  from the AIA instrument onboard the SDO satellite. The CBPs have a
  tendency to change shape and size along time, to disappear and reappear
  at a corresponding heliographic position, therefore, decision trees
  were also included in the tracking solution. Since our CBP detection
  algorithm uses an active region mask to filter out the CBPs, whose
  centroid is inside the active regions, the number of identifications
  clearly depends on the level of solar activity. Our approach uses the
  commonly applied fitting relation to the latitudinal dependence of the
  rotational velocity, which resulted in calculation of the optimum fit
  parameters as well as the Gegenbauer orthogonal polynomials. Comparison
  of these parameters with the results presented in recent papers on this
  topic shows that our rotational velocity profile indicates slightly
  lower rotational velocities than the profiles obtained with other
  approaches. We also calculate the meridional motion of the CBPs, but
  comparison with other authors results, clearly show that a 3-day time
  interval is too short to estimate the latitudinal dependence of the
  CBP meridional motion. Distributions of the rotational velocity and
  meridional motion velocity uncertainties show that 85% of uncertainty
  values are lower than 1 degree/day. The evaluation of our test results
  shows that the applied algorithm is a promising tool that can help to
  refine the solar rotational profile.

Title: Oscillations and Waves in Radio Source of Drifting Pulsation
    Structures
Authors: Karlický, Marian; Rybák, Ján; Bárta, Miroslav
Bibcode: 2018SoPh..293...62K
Altcode: 2018arXiv180306148K
  Drifting pulsation structures (DPSs) are considered to be radio
  signatures of the plasmoids formed during magnetic reconnection
  in the impulsive phase of solar flares. In the present paper
  we analyze oscillations and waves in seven examples of drifting
  pulsation structures, observed by the 800 - 2000 MHz Ondřejov
  Radiospectrograph. For their analysis we use a new type of oscillation
  maps, which give us much more information as regards processes
  in DPSs than that in previous analyses. Based on these oscillation
  maps, made from radio spectra by the wavelet technique, we recognized
  quasi-periodic oscillations with periods ranging from about 1 to 108
  s in all studied DPSs. This strongly supports the idea that DPSs are
  generated during a fragmented magnetic reconnection. Phases of most
  the oscillations in DPSs, especially for the period around 1 s, are
  synchronized ("infinite" frequency drift) in the whole frequency range
  of DPSs. For longer periods in some DPSs we found that the phases of the
  oscillations drift with the frequency drift in the interval from −17
  to +287 MHzs−<SUP>1</SUP>. We propose that these drifting phases can
  be caused (a) by the fast or slow magnetosonic waves generated during
  the magnetic reconnection and propagating through the plasmoid, (b) by
  a quasi-periodic structure in the plasma inflowing to the reconnection
  forming a plasmoid, and (c) by a quasi-periodically varying reconnection
  rate in the X-point of the reconnection close to the plasmoid.

Title: Spectroscopic Inversions of the Ca II 8542 Å Line in a
    C-class Solar Flare
Authors: Kuridze, D.; Henriques, V.; Mathioudakis, M.; Koza, J.;
   Zaqarashvili, T. V.; Rybák, J.; Hanslmeier, A.; Keenan, F. P.
Bibcode: 2017ApJ...846....9K
Altcode: 2017arXiv170800472K
  We study the C8.4-class solar flare SOL2016-05-14T11:34 UT using
  high-resolution spectral imaging in the Ca II 8542 Å line obtained
  with the CRISP imaging spectropolarimeter on the Swedish 1 m Solar
  Telescope. Spectroscopic inversions of the Ca II 8542 Å line using
  the non-LTE code NICOLE are used to investigate the evolution of
  the temperature and velocity structure in the flaring chromosphere. A
  comparison of the temperature stratification in flaring and non-flaring
  areas reveals strong footpoint heating during the flare peak in the
  lower atmosphere. The temperature of the flaring footpoints between
  {log} {τ }<SUB>500</SUB> ≈ -2.5 {and} -3.5, where τ <SUB>500</SUB>
  is the continuum optical depth at 500 nm, is ∼ 5{--}6.5 {kK} close
  to the flare peak, reducing gradually to ∼ 5 {kK}. The temperature in
  the middle and upper chromosphere, between {log} {τ }<SUB>500</SUB>≈
  -3.5 and -5.5, is estimated to be ∼6.5-20 kK, decreasing to preflare
  temperatures, ∼5-10 kK, after approximately 15 minutes. However, the
  temperature stratification of the non-flaring areas is unchanged. The
  inverted velocity fields show that the flaring chromosphere is dominated
  by weak downflowing condensations at the formation height of Ca II
  8542 Å.

Title: Spectral Characteristics of the He I D<SUB>3</SUB> Line in
    a Quiescent Prominence Observed by THEMIS
Authors: Koza, Július; Rybák, Ján; Gömöry, Peter; Kozák, Matúš;
   López Ariste, Arturo
Bibcode: 2017SoPh..292...98K
Altcode: 2017arXiv171209255K
  We analyze the observations of a quiescent prominence acquired by
  the Téléscope Heliographique pour l'Étude du Magnetisme et des
  Instabilités Solaires (THEMIS) in the He I 5876 Å (He I D<SUB>3</SUB>)
  multiplet aiming to measure the spectral characteristics of the He
  I D<SUB>3</SUB> profiles and to find for them an adequate fitting
  model. The component characteristics of the He I D<SUB>3</SUB> Stokes I
  profiles are measured by the fitting system by approximating them with
  a double Gaussian. This model yields an He I D<SUB>3</SUB> component
  peak intensity ratio of 5.5 ±0.4 , which differs from the value of
  8 expected in the optically thin limit. Most of the measured Doppler
  velocities lie in the interval ± 5 km s<SUP>−1</SUP>, with a standard
  deviation of ± 1.7 km s<SUP>−1</SUP> around the peak value of 0.4
  km s<SUP>−1</SUP>. The wide distribution of the full-width at half
  maximum has two maxima at 0.25 Å and 0.30 Å for the He I D<SUB>3</SUB>
  blue component and two maxima at 0.22 Å and 0.31 Å for the red
  component. The width ratio of the components is 1.04 ±0.18 . We show
  that the double-Gaussian model systematically underestimates the blue
  wing intensities. To solve this problem, we invoke a two-temperature
  multi-Gaussian model, consisting of two double-Gaussians, which
  provides a better representation of He I D<SUB>3</SUB> that is free
  of the wing intensity deficit. This model suggests temperatures of
  11.5 kK and 91 kK, respectively, for the cool and the hot component
  of the target prominence. The cool and hot components of a typical He
  I D<SUB>3</SUB> profile have component peak intensity ratios of 6.6
  and 8, implying a prominence geometrical width of 17 Mm and an optical
  thickness of 0.3 for the cool component, while the optical thickness of
  the hot component is negligible. These prominence parameters seem to
  be realistic, suggesting the physical adequacy of the multi-Gaussian
  model with important implications for interpreting He I D<SUB>3</SUB>
  spectropolarimetry by current inversion codes.

Title: Oscillations in the 45 - 5000 MHz Radio Spectrum of the 18
    April 2014 Flare
Authors: Karlický, Marian; Rybák, Ján; Monstein, Christian
Bibcode: 2017SoPh..292...94K
Altcode: 2017arXiv170602836K
  Using a new type of oscillation map, made from the radio spectra
  by the wavelet technique, we study the 18 April 2014 M7.3 flare
  (SOL2014-04-18T13:03:00L245C017). We find a quasi-periodic character
  of this flare with periods in the range 65 - 115 seconds. At the
  very beginning of this flare, in connection with the drifting
  pulsation structure (plasmoid ejection), we find that the 65 - 115
  s oscillation phase slowly drifts towards lower frequencies, which
  indicates an upward propagating wave initiated at the start of the
  magnetic reconnection. Many periods (1 - 200 seconds) are found in
  the drifting pulsation structure, which documents multi-scale and
  multi-periodic processes. On this drifting structure, fiber bursts
  with a characteristic period of about one second are superimposed,
  whose frequency drift is similar to that of the drifting 65 - 115 s
  oscillation phase. We also checked periods found in this flare by the
  EUV Imaging Spectrometer (EIS)/Hinode and Interface Region Imaging
  Spectrograph (IRIS) observations. We recognize the type III bursts
  (electron beams) as proposed, but their time coincidence with the
  EIS and IRIS peaks is not very good. The reason probably is that the
  radio spectrum is a whole-disk record consisting of all bursts from any
  location, while the EIS and IRIS peaks are emitted only from locations
  of slits in the EIS and IRIS observations.

Title: Oscillation Maps in the Broadband Radio Spectrum of the 1
    August 2010 Event
Authors: Karlický, M.; Rybák, J.
Bibcode: 2017SoPh..292....1K
Altcode: 2016arXiv161102074K
  We search for indications of waves in the 25 - 2000 MHz radio spectrum
  of the 1 August 2010 event (SOL2010-08-01T08:57:00L075C013), where fast
  propagating waves in the solar corona with periods of 181, 69, and 40
  seconds were detected in UV observations. Using the wavelet technique,
  we construct a new type of oscillation map for selected periods in the
  whole domain of the radio spectrum. While an oscillation with a period
  of 181 seconds was recognized in the whole 25 - 2000 MHz radio spectrum,
  oscillations with periods of 69 and 40 seconds were only confirmed
  in the 250 - 870 MHz frequency range. In the 800 - 2000 MHz range we
  found periods of 50 and 80 seconds. Moreover, in the 250 - 870 MHz
  frequency range, an oscillation with a period of about 420 seconds was
  detected. We also made maps of phases of the 181-second oscillations in
  order to analyze their frequency drift. At the beginning of the radio
  event, the phase of the 181-second oscillation in the 2000 - 500 MHz
  frequency range drifts toward lower frequencies. On the other hand,
  we found that the phase is nearly synchronous at frequencies 25 - 500
  MHz. While the phase drift at higher frequencies can be interpreted
  as being caused by the UV wave, the synchronization of the phase
  on lower frequencies is explained by the fast electron beams, whose
  acceleration is modulated by the UV wave. Owing to this modulation,
  the electron beams are accelerated with the period of the UV wave
  (181 seconds). These beams propagate upward through the solar corona
  and generate the 25 - 500 MHz radio emission with the 181-second
  period. The 25 - 500 MHz radio emission, which corresponds to a large
  interval of heights in the solar corona, is nearly synchronous because
  of the high beam velocity (≈c /3 , where c is the light speed).

Title: Probing the lower solar atmosphere with CRSIP-SST Data
Authors: Hanslmeier, Arnold; Zaqarashvili, Teimuraz; Koza, Julius;
   Rybak, Jan
Bibcode: 2017psio.confE.113H
Altcode:
  No abstract at ADS

Title: NLTE modeling of a small active region filament observed with
    the VTT
Authors: Schwartz, P.; Balthasar, H.; Kuckein, C.; Koza, J.; Gömöry,
   P.; Rybák, J.; Heinzel, P.; Kučera, A.
Bibcode: 2016AN....337.1045S
Altcode:
  An active region mini-discretionary-filament was observed with the
  Vacuum Tower Telescope (VTT) in Tenerife simultaneously in the He
  I infrared triplet using the Tenerife Infrared Polarimeter 1 (TIP
  1), in Hα with the TESOS Fabry-Pérot interferometer, and in Ca II
  8542 Å with the VTT spectrograph. The spectropolarimetric data were
  inverted using the HAZEL code and Hα profiles were modelled by solving
  a NLTE radiative transfer in a simple isobaric and isothermal 2D slab
  irradiated both from its bottom and sides from the solar surface. It was
  found that the mini-discretionary-filament is composed of horizontal
  fluxtubes, along which the cool plasma of T∼10 000 K can flow with
  very large, even supersonic, velocities.

Title: Broadband microwave sub-second pulsations in an expanding
    coronal loop of the 2011 August 10 flare
Authors: Mészárosová, H.; Rybák, J.; Kashapova, L.; Gömöry,
   P.; Tokhchukova, S.; Myshyakov, I.
Bibcode: 2016A&A...593A..80M
Altcode: 2016arXiv160904217M
  <BR /> Aims: We studied the characteristic physical properties and
  behavior of broadband microwave sub-second pulsations observed in
  an expanding coronal loop during the GOES C2.4 solar flare on 2011
  August 10. <BR /> Methods: The complex microwave dynamic spectrum and
  the expanding loop images were analyzed with the help of SDO/AIA/HMI,
  RHESSI, and the STEREO/SECCHI-EUVI data processing software, wavelet
  analysis methods, the GX Simulator tool, and the NAFE method. <BR />
  Results: We found sub-second pulsations and other different burst
  groups in the complex radio spectrum. The broadband (bandwidth about
  1 GHz) sub-second pulsations (temporal period range 0.07-1.49 s,
  no characteristic dominant period) lasted 70 s in the frequency
  range 4-7 GHz. These pulsations were not correlated at their
  individual frequencies, had no measurable frequency drift, and zero
  polarization. In these pulsations, we found the signatures of fast
  sausage magnetoacoustic waves with the characteristic periods of 0.7
  and 2 s. The other radio bursts showed their characteristic frequency
  drifts in the range of -262-520 MHz s<SUP>-1</SUP>. They helped us to
  derive average values of 20-80 G for the coronal magnetic field strength
  in the place of radio emission. It was revealed that the microwave
  event belongs to an expanding coronal loop with twisted sub-structures
  observed in the 131, 94, and 193 Å SDO/AIA channels. Their slit-time
  diagrams were compared with the location of the radio source at 5.7 GHz
  to realize that the EUV intensity of the expanding loop increased just
  before the radio source triggering. We reveal two EUV bidirectional
  flows that are linked with the start time of the loop expansion. Their
  positions were close to the radio source and propagated with velocities
  within a range of 30-117 km s<SUP>-1</SUP>. <BR /> Conclusions: We
  demonstrate that periodic regime of the electron acceleration in a model
  of the quasi-periodic magnetic reconnection might be able to explain
  physical properties and behavior of the sub-second pulsations. The
  depolarization process of the microwave emission might be caused by
  a plasma turbulence in the radio source. Finally, the observed EUV
  flows might be linked with reconnection outflows.

Title: Is it Possible to Use the Green Coronal Line Instead of X rays
    to Cancel an Effect of the Coronal Emissivity Deficit in Estimation of
    the Prominence Total Mass from Decrease of the EUV-corona Intensities?
Authors: Schwartz, P.; Heinzel, P.; Jejčič, S.; Rybák, J.; Kotrč,
   P.; Fárník, F.; Kupryakov, Yu. A.; Deluca, E. E.; Golub, L.; Jibben,
   P. R.; Anzer, U.; Tlatov, A. G. .; Guseva, S. A.
Bibcode: 2016ASPC..504...89S
Altcode:
  Total masses of six quiescent prominences observed from April through
  June 2011 were estimated using multi-spectral observations (in EUV,
  X-rays, Hα, and Ca &lt;small&gt;II&lt;/small&gt; H). The method for
  the total mass estimation is based on the fact that the intensity
  of the EUV solar corona at wavelengths below 912 Å is reduced at a
  prominence by the absorption in resonance continua (photoionisation)
  of hydrogen and possibly by helium and subsequently an amount of
  absorbed radiation is proportional to the column density of hydrogen
  and helium plasma. Moreover, the deficit of the coronal emissivity in
  volume occupied by the cool prominence plasma also contributes to the
  intensity decrease. The observations in X-rays which are not absorbed
  by the prominence plasma, allow us to separate these two mechanisms
  from each other. The X-ray observations of XRT onboard the Hinode
  satellite made with the Al-mesh focal filter were used because the
  X-ray coronal radiation formed in plasma of temperatures of the order
  of 10<SUP>6</SUP> K was registered and EUV spectral lines occurring in
  the 193, 211 and 335 Å channels of the Atmospheric Imaging Assembly
  of the Solar Dynamics Observatory satellite are also formed at such
  temperatures. Unfortunately, the Al-mesh filter has a secondary peak
  of the transmittance at around 171 Å which causes a contribution
  from the EUV corona to the measured data of up to 11 % in the quiet
  corona. Thus, absorption in prominence plasma influences XRT X-ray
  data when using the Al-mesh filter. On the other hand, other X-ray XRT
  filters are more sensitive to plasma of much higher temperatures (log
  T of the order of 7), thus observations using these filters cannot
  be used together with the AIA observations in the method for mass
  estimations. This problem could be solved using observations in the
  green coronal line instead of X-rays. Absorption of the green coronal
  line by a prominence plasma is negligible and this line is formed at
  temperatures of the order of 10<SUP>6</SUP> K. We compare values of
  the total mass of the prominence observed on 20 October 2012 on the
  SE limb estimated when using XRT X-ray observations and observations
  in the green coronal line obtained at Kislovodsk Mountain Astronomical
  Station of the Pulkovo observatory (Russia).

Title: The Effect of Area Averaging on the Approximated Profile of
    the H α Spectral Line
Authors: Bodnárová, M.; Utz, D.; Rybák, J.
Bibcode: 2016ASPC..504...23B
Altcode:
  The Hα line is massively used as a diagnostics of the
  chromosphere. Often one needs to average the line profile over some
  area to increase the signal to noise ratio. Thus it is important to
  understand how derived parameters vary with changing approximations. In
  this study we investigate the effect of spatial averaging of a selected
  area on the temporal variations of the width, the intensity and the
  Dopplershift of the Hα spectral line profile. The approximated profile
  was deduced from co-temporal observations in five points throughout
  the Hα line profile obtained by the tunable Lyot filter installed
  on the Dutch Open Telescope. We found variations of the intensity and
  the Doppler velocities, which were independent of the size of the area
  used for the computation of the area averaged Hα spectral line profile.

Title: Non-LTE Inversion of Spectropolarimetric and Spectroscopic
    Observations of a Small Active-region Filament Observed at the VTT
Authors: Schwartz, P.; Balthasar, H.; Kuckein, C.; Koza, J.; Gömöry,
   P.; Rybák, J.; Kučera, A.; Heinzel, P.
Bibcode: 2016ASPC..504..205S
Altcode:
  An active region mini-filament was observed by VTT simultaneously
  in the He&lt;small&gt;I&lt;/small&gt; 10 830 Å triplet by the TIP 1
  spectropolarimeter, in Hα by the TESOS Fabry-Pérot interferometer, and
  in Ca &lt;small&gt;II&lt;/small&gt; 8542 Å by the VTT spectrograph. The
  spectropolarimetric data were inverted using the HAZEL code and Hα
  profiles were modelled solving a NLTE radiative transfer in a simple
  isobaric and isothermal 2D slab irradiated both from bottom and
  sides. It was found that the mini-filament is composed of horizontal
  fluxtubes, along which the cool plasma of T∼10 000 K can flow by
  very large - even supersonic - velocities.

Title: The CoMP-S Instrument at the Lomnický Peak Observatory:
    Status Report
Authors: Kučera, A.; Ambróz, J.; Gömöry, P.; Habaj, P.; Kavka,
   J.; Kozák, M.; Schwartz, P.; Rybák, J.; Tomczyk, S.; Sewell, S.;
   Aumiller, P.; Summers, R.; Watt, A.
Bibcode: 2016ASPC..504..321K
Altcode:
  The Coronal Multi-channel Polarimeter for Slovakia (CoMP-S) has
  been installed at the high-altitude Lomnicky Peak Observatory of the
  Astronomical Institute of SAS (2633 m a.s.l.) in 2011. The instrument
  was designed and manufactured by HAO/NCAR (Boulder, USA) with a
  tunable Lyot filter and polarimeter for visible and near IR spectral
  regions. This instrument is proposed for coronagraphic observations of
  magnetic and velocity fields in the solar corona and in prominences. A
  fundamental upgrade of this instrument has been prepared with pair
  of cameras sensitive in the near IR spectral region in a new camera
  module. This upgrade is being incorporated to the instrument in course
  of the year 2014. In this contribution the technical parameters of the
  final configuration of the CoMP-S instrument containing four cameras,
  covering both visible and near IR spectral regions, are described. We
  also present a potential of the CoMP-S instrument for coronagraphic
  spectro-polarimetric observations of the solar corona and prominences
  with a capability for sequential measurements of the spectral profiles
  of all prominent emission lines in spectral region from 500 to 1100 nm.

Title: Waves and Magnetism in the Solar Atmosphere (WAMIS)
Authors: Ko, Yuan-Kuen; Moses, John; Laming, John; Strachan, Leonard;
   Tun Beltran, Samuel; Tomczyk, Steven; Gibson, Sarah; Auchere, Frederic;
   Casini, Roberto; Fineschi, Silvano; Knoelker, Michael; Korendyke,
   Clarence; McIntosh, Scott; Romoli, Marco; Rybak, Jan; Socker, Dennis;
   Vourlidas, Angelos; Wu, Qian
Bibcode: 2016FrASS...3....1K
Altcode:
  Comprehensive measurements of magnetic fields in the solar corona have
  a long history as an important scientific goal. Besides being crucial
  to understanding coronal structures and the Sun’s generation of space
  weather, direct measurements of their strength and direction are also
  crucial steps in understanding observed wave motions. In this regard,
  the remote sensing instrumentation used to make coronal magnetic field
  measurements is well suited to measuring the Doppler signature of waves
  in the solar structures. In this paper, we describe the design and
  scientific values of the Waves and Magnetism in the Solar Atmosphere
  (WAMIS) investigation. WAMIS, taking advantage of greatly improved
  infrared filters and detectors, forward models, advanced diagnostic
  tools and inversion codes, is a long-duration high-altitude balloon
  payload designed to obtain a breakthrough in the measurement of
  coronal magnetic fields and in advancing the understanding of the
  interaction of these fields with space plasmas. It consists of a 20 cm
  aperture coronagraph with a visible-IR spectro-polarimeter focal plane
  assembly. The balloon altitude would provide minimum sky background and
  atmospheric scattering at the wavelengths in which these observations
  are made. It would also enable continuous measurements of the strength
  and direction of coronal magnetic fields without interruptions from
  the day-night cycle and weather. These measurements will be made
  over a large field-of-view allowing one to distinguish the magnetic
  signatures of different coronal structures, and at the spatial and
  temporal resolutions required to address outstanding problems in
  coronal physics. Additionally, WAMIS could obtain near simultaneous
  observations of the electron scattered K-corona for context and to
  obtain the electron density. These comprehensive observations are not
  provided by any current single ground-based or space observatory. The
  fundamental advancements achieved by the near-space observations of
  WAMIS on coronal field would point the way for future ground based
  and orbital instrumentation.

Title: Waves and Magnetism in the Solar Atmosphere (WAMIS)
Authors: Strachan, L.; Ko, Y. -K.; Moses, J. D.; Laming, J. M.;
   Auchere, F.; Casini, R.; Fineschi, S.; Gibson, S.; Knoelker, M.;
   Korendyke, C.; Mcintosh, S.; Romoli, M.; Rybak, J.; Socker, D.;
   Tomczyk, S.; Vourlidas, A.; Wu, Q.
Bibcode: 2015IAUS..305..121S
Altcode:
  Magnetic fields in the solar atmosphere provide the energy for most
  varieties of solar activity, including high-energy electromagnetic
  radiation, solar energetic particles, flares, and coronal mass
  ejections, as well as powering the solar wind. Despite the fundamental
  role of magnetic fields in solar and heliospheric physics, there
  exist only very limited measurements of the field above the base of
  the corona. What is needed are direct measurements of not only the
  strength and orientation of the magnetic field but also the signatures
  of wave motions in order to better understand coronal structure, solar
  activity, and the role of MHD waves in heating and accelerating the
  solar wind. Fortunately, the remote sensing instrumentation used to make
  magnetic field measurements is also well suited to measure the Doppler
  signature of waves in the solar structures. We present here a mission
  concept for the Waves And Magnetism In the Solar Atmosphere (WAMIS)
  experiment which is proposed for a NASA long-duration balloon flight.

Title: Dual instrument for Flare and CME onset observations -
    Double solar Coronagraph with Solar Chromospheric Detector and
    Coronal Multi-channel Polarimeter at Lomnicky stit Observatory
Authors: Kucera, Ales; Tomczyk, Steven; Rybak, Jan; Sewell, Scott;
   Gomory, Peter; Schwartz, Pavol; Ambroz, Jaroslav; Kozak, Matus
Bibcode: 2015IAUGA..2246687K
Altcode:
  We report on unique dual instrument developed for simultaneous
  measurements of velocity and magnetic fields in the solar chromosphere
  and corona. We describe the technical parameters and capability of
  the Coronal Multi-channel Polarimeter (CoMP-S) and Solar Chromospheric
  detector (SCD) mounted at the Double solar coronagraph at Lomnicky Stit
  Observatory and working simultaneously with strictly parallel pointing
  of both coronagraphs. The CoMP-S is 2D spectropolarimeter designed
  for observations of VIS and near-IR emission lines of prominences
  and corona with operating spectral range: 500 - 1100 nm, sequential
  measurement of several VIS and near-IR lines. Its field of view is
  14 arcmin x 11 arcmin. It consists of 4-stage calcite Lyot filter
  followed by the ferro-liquid crystal polarizer and four cameras (2
  visible, 2 infrared). The capability is to deliver 2D full Stokes I,
  Q, U, V, using registration with 2 IR cameras (line + background) and
  2 VIS cameras (line + background) SCD is a single beam instrument to
  observe bright chromosphere. It is a combination of tunable filter and
  polarimeter. Spectral resolution of the SCD ranges from 0.046 nm for
  observations of the HeI 1083 nm line up to to 25 pm is for observation
  of the HeI 587.6 nm line. The birefringent filter of the SCD has high
  spectral resolution, as well as spatial resolution (1.7 arcseconds)
  and temporal resolution (10 seconds) First results are also reported
  and discussed.

Title: Waves and Magnetism in the Solar Atmosphere (WAMIS)
Authors: Ko, Y. K.; Auchere, F.; Casini, R.; Fineschi, S.; Gibson,
   S. E.; Knoelker, M.; Korendyke, C.; Laming, J. M.; Mcintosh, S. W.;
   Moses, J. D.; Romoli, M.; Rybak, J.; Socker, D. G.; Strachan, L.;
   Tomczyk, S.; Vourlidas, A.; Wu, Q.
Bibcode: 2014AGUFMSH53B4221K
Altcode:
  Magnetic fields in the solar atmosphere provide the energy for most
  varieties of solar activity, including high-energy electromagnetic
  radiation, solar energetic particles, flares, and coronal mass
  ejections, as well as powering the solar wind. Despite the fundamental
  role of magnetic fields in solar and heliospheric physics, there
  exists only very limited measurements of the field above the base of
  the corona. What is needed are direct measurements of not only the
  strength and orientation of the magnetic field but also the signatures
  of wave motions in order to better understand coronal structure,
  solar activity and the role of MHD waves in heating and accelerating
  the solar wind. Fortunately, the remote sensing instrumentation used
  to make magnetic field measurements is also well suited for measuring
  the Doppler signature of waves in the solar structures. With this
  in mind, we are proposing the WAMIS (Waves and Magnetism in the
  Solar Atmosphere) investigation. WAMIS will take advantage of greatly
  improved infrared (IR) detectors, forward models, advanced diagnostic
  tools and inversion codes to obtain a breakthrough in the measurement
  of coronal magnetic fields and in the understanding of the interaction
  of these fields with space plasmas. This will be achieved with a high
  altitude balloon borne payload consisting of a coronagraph with an IR
  spectro-polarimeter focal plane assembly. The balloon platform provides
  minimum atmospheric absorption and scattering at the IR wavelengths in
  which these observations are made. Additionally, a NASA long duration
  balloon flight mission from the Antarctic can achieve continuous
  observations over most of a solar rotation, covering all of the key
  time scales for the evolution of coronal magnetic fields. With these
  improvements in key technologies along with experience gained from
  current ground-based instrumentation, WAMIS will provide a low-cost
  mission with a high technology readiness leve.

Title: Magnetoacoustic Waves Propagating along a Dense Slab and
    Harris Current Sheet and their Wavelet Spectra
Authors: Mészárosová, Hana; Karlický, Marian; Jelínek, Petr;
   Rybák, Ján
Bibcode: 2014ApJ...788...44M
Altcode:
  Currently, there is a common endeavor to detect magnetoacoustic
  waves in solar flares. This paper contributes to this topic using an
  approach of numerical simulations. We studied a spatial and temporal
  evolution of impulsively generated fast and slow magnetoacoustic
  waves propagating along the dense slab and Harris current sheet using
  two-dimensional magnetohydrodynamic numerical models. Wave signals
  computed in numerical models were used for computations of the temporal
  and spatial wavelet spectra for their possible comparison with those
  obtained from observations. It is shown that these wavelet spectra allow
  us to estimate basic parameters of waveguides and perturbations. It was
  found that the wavelet spectra of waves in the dense slab and current
  sheet differ in additional wavelet components that appear in association
  with the main tadpole structure. These additional components are new
  details in the wavelet spectrum of the signal. While in the dense slab
  this additional component is always delayed after the tadpole head, in
  the current sheet this component always precedes the tadpole head. It
  could help distinguish a type of the waveguide in observed data. We
  present a technique based on wavelets that separates wave structures
  according to their spatial scales. This technique shows not only
  how to separate the magnetoacoustic waves and waveguide structure in
  observed data, where the waveguide structure is not known, but also
  how propagating magnetoacoustic waves would appear in observations
  with limited spatial resolutions. The possibilities detecting these
  waves in observed data are mentioned.

Title: On Dynamics of G-Band Bright Points
Authors: Bodnárová, M.; Utz, D.; Rybák, J.
Bibcode: 2014SoPh..289.1543B
Altcode: 2013arXiv1312.5464B
  Various parameters describing the dynamics of G-band bright points
  (GBPs) were derived from G-band images, acquired by the Dutch Open
  Telescope (DOT), of a quiet region close to the disk center. Our
  study is based on four commonly used diagnostics (effective velocity,
  change in the effective velocity, change in the direction angle, and
  centrifugal acceleration) and two new ones (rate of motion and time lag
  between recurrence of GBPs). The results concerning the commonly used
  parameters are in agreement with previous studies for a comparable
  spatial and temporal resolution of the used data. The most probable
  value of the effective velocity is ∼ 0.9 km s<SUP>−1</SUP>,
  whereas we found a deviation of the effective velocity distribution
  from the expected Rayleigh function for velocities in the range from
  2 to 4 km s<SUP>−1</SUP>. The change in the effective velocity
  distribution is consistent with a Gaussian one with FWHM=0.079 km
  s<SUP>−2</SUP>. The distribution of the centrifugal acceleration
  exhibits a highly exponential nature (a symmetric Gaussian centered
  at the zero value). To broaden our understanding of the dynamics of
  GBPs, two new parameters were defined: the real displacement between
  their appearance and disappearance (rate of motion) and the frequency
  of their recurrence at the same locations (time lag). For ∼ 45 % of
  the tracked GBPs, their displacement was found to be small compared to
  their size (the rate of motion smaller than one). The locations of the
  tracked GBPs mainly cover the boundaries of supergranules representing
  the network, and there is no significant difference in the locations
  of GBPs with small (m&lt;1) and large (m&gt;2) values of the rate of
  motion. We observed a difference in the overall trend of the obtained
  distribution for the values of the time lag smaller (slope of the trend
  line being −0.14) and greater (−0.03) than ∼ 7 min. The time
  lags mostly lie within the interval of ∼ 2 - 3 min, with those up to
  ∼ 4 min being more abundant than longer ones. Results for both new
  parameters indicate that the locations of different dynamical types
  of GBPs (stable/farther traveling or with short/long lifetimes) are
  bound to the locations of more stable and long-living magnetic field
  concentrations. Thus, the disappearance/reappearance of the tracked
  GBPs cannot be perceived as the disappearance/reappearance of their
  corresponding magnetic field concentrations.

Title: Inferring spectral characteristics of the Hα spectral line
    observed by the DOT Lyot filter
Authors: Koza, J.; Rybák, J.; Gömöry, P.; Kučera, A.
Bibcode: 2014CoSka..44...43K
Altcode:
  A tunable Lyot filter can serve as a spectroscopic device rendering
  wide-field 2-D pseudospectroscopy of solar structures and follow-up
  crude reconstruction of a spectral line profile at each pixel within the
  field of view. We developed a method of inferring of the Doppler shift,
  the core intensity, the core width, and the core asymmetry of the Hα
  spectral line observed by the Lyot filter installed on the Dutch Open
  Telescope (DOT). The spectral characteristics are inferred through the
  fitting of five intensity samples, separated from each other by 0.35 Å,
  by a 4<SUP>th</SUP>-order polynomial, a Gaussian, and a parabola. We
  use the atlas Hα profile as a reference in estimating deviations
  of the derived spectral characteristics. The Gaussian is the most
  preferable means for measurements of the Doppler shift with deviations
  smaller than 1 km s<SUP>-1</SUP>. When using the 4<SUP>th</SUP>-order
  polynomial, deviations are within the interval ±2.5 km s<SUP>-1</SUP>,
  but it renders comparable deviations of the core intensity and the
  width as the Gaussian. The deviations are largely insensitive to the
  shape of the filter transmission, but depend mostly non-linearly on
  the Doppler shift. Therefore, they do not cancel out if the spectral
  characteristics are represented by their relative variations. Results
  can be used as corrections of spectral characteristics extracted from
  area-averaged Hα profiles acquired by the DOT Lyot filter.

Title: Transmission profile of the Dutch Open Telescope Hα Lyot
    filter
Authors: Koza, J.; Hammerschlag, R. H.; Rybák, J.; Gömöry, P.;
   Kučera, A.; Schwartz, P.
Bibcode: 2014AN....335..409K
Altcode: 2017arXiv171209253K
  Context Accurate knowledge of the spectral transmission profile of
  a Lyot filter is important, in particular in comparing observations
  with simulated data. The paper summarizes available facts about the
  transmission profile of the Dutch Open Telescope (DOT) Hα Lyot filter
  pointing to a discrepancy between sidelobe-free Gaussian-like profile
  measured spectroscopically and signatures of possible leakage of
  parasitic continuum light in DOT Hα images. We compute wing-to-center
  intensity ratios resulting from convolutions of Gaussian and square
  of the sinc function with the Hα atlas profile and compare them with
  the ratios derived from observations of the quiet Sun chromosphere at
  disk center. We interpret discrepancies between the anticipated and
  observed ratios and the sharp limb visible in the DOT Hα image as an
  indication of possible leakage of parasitic continuum light. A method
  suggested here can be applied also to indirect testing of transmission
  profiles of other Lyot filters. We suggest two theoretical transmission
  profiles of the DOT Hα Lyot filter which should be considered as the
  best available approximations. Conclusive answer can only be given by
  spectroscopic re-measurement of the filter.

Title: Coronal Multi-channel Polarimeter at the Lomnicky Peak
    Observatory
Authors: Schwartz, P.; Ambroz, J.; Gömöry, P.; Kozák, M.; Kučera,
   A.; Rybák, J.; Tomczyk, S.; Sewell, S.; Aumiller, P.; Summers, R.;
   Sutherland, L.; Watt, A.
Bibcode: 2014IAUS..300..521S
Altcode:
  Coronal Multi-channel Polarimeter (CoMP-S), developed by HAO/NCAR, has
  been introduced to regular operation at the Lomnicky Peak Observatory
  (High Tatras in northern Slovakia, 2633 m a.s.l.) of the Astronomical
  Institute of Slovak Academy of Sciences. We present here the technical
  parameters of the current version of the instrument and its potential
  for observations of prominences in the visual and near-IR spectral
  regions. The first results derived from observations of prominences
  in the Hα emission line taken during a coordinated observing campaign
  of several instruments in October 2012 are shown here.

Title: Space- and Ground-based Coronal Spectro-Polarimetry
Authors: Fineschi, Silvano; Bemporad, Alessandro; Rybak, Jan;
   Capobianco, Gerardo
Bibcode: 2014cosp...40E.868F
Altcode:
  This presentation gives an overview of the near-future perspectives of
  ultraviolet and visible-light spectro-polarimetric instrumentation
  for probing coronal magnetism from space-based and ground-based
  observatories. Spectro-polarimetric imaging of coronal emission-lines
  in the visible-light wavelength-band provides an important diagnostics
  tool of the coronal magnetism. The interpretation in terms of Hanle and
  Zeeman effect of the line-polarization in forbidden emission-lines
  yields information on the direction and strength of the coronal
  magnetic field. As study case, this presentation will describe the
  Torino Coronal Magnetograph (CorMag) for the spectro-polarimetric
  observation of the FeXIV, 530.3 nm, forbidden emission-line. CorMag
  - consisting of a Liquid Crystal (LC) Lyot filter and a LC linear
  polarimeter - has been recently installed on the Lomnicky Peak
  Observatory 20cm Zeiss coronagraph. The preliminary results from CorMag
  will be presented. The linear polarization by resonance scattering
  of coronal permitted line-emission in the ultraviolet (UV)can be
  modified by magnetic fields through the Hanle effect. Space-based
  UV spectro-polarimeters would provide an additional tool for the
  disgnostics of coronal magnetism. As a case study of space-borne
  UV spectro-polarimeters, this presentation will describe the future
  upgrade of the Sounding-rocket Coronagraphic Experiment (SCORE) to
  include the capability of imaging polarimetry of the HI Lyman-alpha,
  121.6 nm. SCORE is a multi-wavelength imager for the emission-lines,
  HeII 30.4 nm and HI 121.6 nm, and visible-light broad-band emission
  of the polarized K-corona. SCORE has flown successfully in 2009. This
  presentation will describe how in future re-flights SCORE could observe
  the expected Hanle effect in corona with a HI Lyman-alpha polarimeter.

Title: Search for Alfvén waves in a bright network element observed
    in Hα
Authors: Koza, J.; Sütterlin, P.; Gömöry, P.; Rybák, J.;
   Kučera, A.
Bibcode: 2013CoSka..43....5K
Altcode: 2013arXiv1304.4027K
  Alfvén waves are considered as potential transporters of energy
  heating the solar corona. We seek spectroscopic signatures of the
  Alfvén waves in the chromosphere occupied by a bright network element,
  investigating temporal variations of the spectral width, intensity,
  Dopplershift, and the asymmetry of the core of the Hα spectral
  line observed by the tunable Lyot filter installed on the Dutch Open
  Telescope. The spectral characteristics are derived through the fitting
  of five intensity samples, separated from each other by 0.35 Å, by a
  4<SUP>th</SUP>-order polynomial. The bright network element displays
  the most pronounced variations of the Dopplershift varying from 0 to 4
  km s<SUP>-1</SUP> about the average of 1.5 km s<SUP>-1</SUP>. This fact
  implies a persistent redshift of the Hα core with a redward asymmetry
  of about 0.5 km s<SUP>-1</SUP>, suggesting an inverse-C bisector. The
  variations of the core intensity up to ±10 % and the core width up to
  ±5 % about the respective averages are much less pronounced, but still
  detectable. The core intensity variations lag behind the Dopplershift
  variations about 2.1 min. The Hα core width tends to correlate with
  the Dopplershift and anticorrelate with the asymmetry, suggesting that
  more redshifted Hα profiles are wider and the broadening of the Hα
  core is accompanied with a change of the core asymmetry from redward
  to blueward. We also found a striking anticorrelation between the
  core asymmetry and the Dopplershift, suggesting a change of the core
  asymmetry from redward to blueward with an increasing redshift of the
  Hα core. The data and the applied analysis do not show meaningful
  tracks of Alfvén waves in the selected network element.

Title: A quiescent prominence observed in the Hα line by the COMP-S
    instrument at the Lomnický Peak Observatory
Authors: Schwartz, P.; Rybák, J.; Kučera, A.; Kozák, M.; Ambróz,
   J.; Gömöry, P.
Bibcode: 2012CoSka..42..135S
Altcode:
  A prominence above the NEE limb was observed by the COMP-S instrument
  attached to the ZEISS coronagraph located at the Lomnický Peak
  Observatory. Observations were carried out on Nov 2, 2011 between
  14:01:13 and 14:11:34 UT. The filter of the instrument was tuned during
  measurements sequentially in five wavelengths within the profile of
  the Hα line: 0, ±1, ±2 Å around 6563 Å. FWHM of the transmission
  function of the filter was ∼0.4Å at these wavelengths. Data were
  not absolutely calibrated, therefore they could be fitted using only a
  simple cloud model (1D geometry, a complete frequency redistribution,
  a source function independent of the optical depth) to diagnose the
  prominence plasma. As five wavelength points in the profile were not
  enough for an automatic fitting, five positions at the prominence were
  chosen for the analysis. Observed data from the five positions were
  simulated using the cloud model and groups of different models were
  found for each position. It means that the wavelength scale of a step
  as large as 1 Å when used for the Hα line is not fine enough for
  estimation of a correct and unique model. Simulating observations
  using three different finer wavelength scales it was found that
  the wavelength scale with a step of 0.3 Å and even more finer in
  the line core (step of 0.1 Å) is already suitable for more precise
  and unambiguous plasma diagnostics. We also show that for correct
  plasma diagnostics it is crucial to take into account an effect of a
  finite width of the transmission function of the filter. If observed
  data were fitted irrespectively of this important effect, an error
  in estimated model parameters could exceed even 100 %, except for
  the Doppler velocities, for which the error would be much smaller,
  e.g. for velocities up to 20 km s<SUP>-1</SUP> the error is below 1 %.

Title: Dependence of Velocity Distributions of Small-Scale Magnetic
    Fields Derived from Hinode/SOT G-band Filtergrams on the Temporal
    Resolution of the Used Data Sets
Authors: Utz, D.; Hanslmeier, A.; Muller, R.; Veronig, A.; Rybák,
   J.; Muthsam, H.
Bibcode: 2012ASPC..454...55U
Altcode:
  The dynamics of isolated small-scale fields in terms of velocities of
  magnetic bright points (MBPs) is addressed in this contribution. The
  empirically determined linear relation between the observed width
  parameter for the Rayleigh velocity distribution of MBPs versus the
  temporal cadence of the acquired data is studied by simulations and a
  simple analytical model. The results of the model and the simulation
  agree with the found relation for the observations. The conclusion we
  draw from the model is that there may be no characteristic velocity
  for MBPs at all.

Title: Magnetoacoustic Wave Trains in the 11 July 2005 Radio Event
    with Fiber Bursts
Authors: Mészárosová, H.; Karlický, M.; Rybák, J.
Bibcode: 2012esrs.book...87M
Altcode:
  A dm-radio emission with fiber bursts observed on 11 July 2005 was
  analyzed using wavelet filtration and spectral methods. In filtered
  radio spectra we found structures with different characteristic
  period P and frequency drift FD: i) fiber substructures (composed
  of dot emissions) with P <SUB>1</SUB>≈ 0.5 s, FD<SUB>1</SUB>=-
  87 MHz s<SUP>-1</SUP> on average, ii) fiber structures with
  P <SUB>2</SUB>≈1.9 s, and iii) drifting structures with P
  <SUB>3</SUB>≈81.4 s, FD<SUB>2</SUB>=- 8.7, + 98.5, and - 21.8 MHz
  s<SUP>-1</SUP>. In the wavelet spectra we recognized patterns having
  the form of tadpoles. They were detected with the same characteristic
  periods P as found for the filtered structures. The frequency
  drift of the tadpole heads is found to be equal to the frequency
  drift of some groups of fibers for the long-period wavelet tadpoles
  (P <SUB>3</SUB>) and to the frequency drift of individual fibers for
  the short-period tadpoles (P <SUB>2</SUB>). Considering these wavelet
  tadpoles as signatures of propagating magnetoacoustic wave trains,
  the results indicate the presence of several wave trains in the fibers'
  source. While the long-period wave trains trigger or modulate a whole
  group of fibers, the short-period ones look like being connected with
  individual fiber bursts. This result supports the model of fibers based
  on magnetoacoustic waves. Using a density model of the solar atmosphere
  we derived the velocities of the magnetoacoustic waves, 107 and 562 km
  s<SUP>-1</SUP>, and setting them equal to the Alfvén ones we estimated
  the magnetic field in the source of fiber bursts as 10.7 and 47.8 G.

Title: Magnetoacoustic Wave Trains in the 11 July 2005 Radio Event
    with Fiber Bursts
Authors: Mészárosová, H.; Karlický, M.; Rybák, J.
Bibcode: 2011SoPh..273..393M
Altcode: 2011SoPh..tmp..128M; 2011SoPh..tmp..183M; 2011SoPh..tmp..252M
  A dm-radio emission with fiber bursts observed on 11 July 2005 was
  analyzed using wavelet filtration and spectral methods. In filtered
  radio spectra we found structures with different characteristic
  period P and frequency drift FD: i) fiber substructures (composed
  of dot emissions) with P<SUB>1</SUB>≈ 0.5 s, FD<SUB>1</SUB>=−
  87 MHz s<SUP>−1</SUP> on average, ii) fiber structures
  with P<SUB>2</SUB>≈1.9 s, and iii) drifting structures with
  P<SUB>3</SUB>≈81.4 s, FD<SUB>2</SUB>=− 8.7, + 98.5, and − 21.8 MHz
  s<SUP>−1</SUP>. In the wavelet spectra we recognized patterns having
  the form of tadpoles. They were detected with the same characteristic
  periods P as found for the filtered structures. The frequency
  drift of the tadpole heads is found to be equal to the frequency
  drift of some groups of fibers for the long-period wavelet tadpoles
  (P<SUB>3</SUB>) and to the frequency drift of individual fibers for
  the short-period tadpoles (P<SUB>2</SUB>). Considering these wavelet
  tadpoles as signatures of propagating magnetoacoustic wave trains,
  the results indicate the presence of several wave trains in the fibers'
  source. While the long-period wave trains trigger or modulate a whole
  group of fibers, the short-period ones look like being connected with
  individual fiber bursts. This result supports the model of fibers
  based on magnetoacoustic waves. Using a density model of the solar
  atmosphere we derived the velocities of the magnetoacoustic waves,
  107 and 562 km s<SUP>−1</SUP>, and setting them equal to the Alfvén
  ones we estimated the magnetic field in the source of fiber bursts as
  10.7 and 47.8 G.

Title: The LSO/KSO Hα prominence catalogue: cross-calibration of data
Authors: Rybák, J.; Gömöry, P.; Mačura, R.; Kučera, A.; Rušin,
   V.; Pötzi, W.; Baumgartner, D.; Hanslmeier, A.; Veronig, A.;
   Temmer, M.
Bibcode: 2011CoSka..41..133R
Altcode:
  We present work on the extension of the homogeneous prominence
  catalogue created for the epoch 1967 — 2009 at the Lomnicky Peak
  Observatory (LSO) by incorporating new data acquired at the Kanzelhöhe
  Observatory for Solar and Environmental Research (KSO). We use data of
  20 Hα prominences observed almost simultaneously at both observatories
  during four days in August/September 2009 to analyze the significance
  of differences of the determined parameters used in the Hα prominence
  catalogue. A reduction of the data from KSO and adaptation of the
  resulting parameters to fit the parameters of the LSO catalogue confirm
  that no special homogenization is needed to create a common catalogue
  data set. Thus, we justified that the LSO catalogue could be extended
  onward in the future using a more comprehensive database of observations
  from KSO.

Title: Separation of solar radio bursts in a complex spectrum
Authors: Mészárosová, Hana; Rybák, Ján; Karlický, Marian;
   Jiřička, Karel
Bibcode: 2011IAUS..274..150M
Altcode:
  Radio spectra, observed during solar flares, are usually very complex
  (many bursts and fine structures). We have developed a new method to
  separate them into individual bursts and analyze them separately. The
  method is used in the analysis of the 0.8-2.0 GHz radio spectrum of the
  April 11, 2001 event, which was rich in drifting pulsating structures
  (DPSs). Using this method we showed that the complex radio spectrum
  consists of at least four DPSs separated with respect to their different
  frequency drifts (-115, -36, -23, and -11 MHz s<SUP>-1</SUP>). These
  DPSs indicate a presence of at least four plasmoids expected to be
  formed in a flaring current sheet. These plasmoids produce the radio
  emission on close frequencies giving thus a mixture of superimposed
  DPSs observed in the radio spectrum.

Title: Separation of drifting pulsating structures in a complex
    radio spectrum of the 2001 April 11 event
Authors: Mészárosová, H.; Rybák, J.; Karlický, M.
Bibcode: 2011A&A...525A..88M
Altcode:
  <BR /> Aims: We present new method of separating a complex radio
  spectrum into single radio bursts. The method is used in the analysis
  of the 0.8-2.0 GHz radio spectrum of the 2001 April 11 event, which
  was rich in drifting pulsating structures. <BR /> Methods: The method
  is based on the wavelet analysis technique, which separates different
  spatial-temporal components (radio bursts) that are difficult to
  recognize in the original radio spectrum. <BR /> Results: We show with
  this method that the complex radio spectrum observed during the 2001
  April 11 event consists of at least four drifting pulsating structures
  (DPSs). These structures were separated with respect to their different
  frequency drifts. The DPSs indicate at least four plasmoids that are
  supposed to be formed in a flaring current sheet.

Title: Heating of the quiet solar corona from measurements of the
    FET/TESIS instrument on-board the KORONAS-FOTON satellite
Authors: Rybák, J.; Gömöry, P.; Benz, A.; Bogachev, P.; Brajša, R.
Bibcode: 2010nspm.conf..107R
Altcode:
  The paper presents the first results of the observations of time
  evolution of the quiet solar corona brightenings obtained due to
  very rapid photography of the corona with full-disk EUV telescopes
  of the FET/TESIS instrument onboard the KORONA FOTON satellite. The
  measurements were performed simultaneously in the emission of the Fe
  IX / X 17.1 and Fe VIII 13.1 spectral lines with 10 second temporal
  cadence and spatial scale of 1.7 arc seconds within one hour. This
  test observation, carried out on 15 July 2009, was analyzed in order
  to determine whether this type of observation can be used to identify
  individual microevents in the solar corona heating that are above the
  tresholds of spatial and temporal resolutions of the observations
  of non-active regions in the solar atmosphere. For this purpose,
  a simple method was used involving cross-correlation of the plasma
  emission time evolution at different temperatures, each time from
  observations of identical elements. The results obtained are confronted
  with the expected observable manifestations of the corona heating
  via nanoflares. TESIS is a set of instruments for the Sun photography
  developed in the Lebedev Physics Institute of the Russian Academy of
  Sciences that was launched into orbit in January 2009.

Title: Koronálny multikanálový polarimeter pre observatórium
Lomnický štít Title: Koronálny multikanálový polarimeter
pre observatórium Lomnický štít Title: Coronal multichannel
    polarimeter for Lomnický štít Observatory.
Authors: Rybák, J.; Ambróz, J.; Gömöry, P.; Kozák, M.; Kučera,
   A.; Tomczyk, S.; Sewell, S.; Summers, R.; Sutherland, L.; Watt, A.
Bibcode: 2010nspm.conf..196R
Altcode:
  The contribution presents the process of development and preparation
  of the Coronal Multi-channel Polarimeter (COMP-S) for the Lomnický
  štít Observatory of the SAS Astronomy Institute. The design of the
  device is based on the experience gained in recent years with the CoMP
  (High Altitude Observatory / NCAR; Boulder, USA) instrument. The device
  will be a combination of two main optical components: the Lyot tunable
  filter and polarimeter, and is prepared specifically for one of the
  20 cm Zeiss coronagraph at the Lomnický štít Observatory where it
  will be installed in 2011. CoMP-S will differ from its predecessor
  in several respects. The most important difference is that CoMP-S
  will be able to observe the corona and chromospheric emission lines
  in the wavelength range from 530 to 1083 nm. This feature will be
  achieved using superachromatic wave plates and dichroic polarizers
  with wide bandwidth. Furthermore, in the CoMP-S instrument new SWIFT
  liquid crystals of Meadowlark Optics company will be used as variable
  retarders instead of nematic liquid crystal retarders (LCVR) which
  will considerably shorten the measuring process. Ferroelectric liquid
  crystals will provide measurements of the full Stokes vector with nearly
  optimal polarization throughout the whole instrument bandwidth. Recently
  developed sCMOS cameras are to provide diffraction limit resolution of
  observations, with the 860x680 arc second field and 30-frames-per-second
  cadence. The device will be used in the Astronomical Observatory of SAS
  at Lomnický štít primarily for spectrum polarimetry of prominences
  and coronal loops of the active solar regions.

Title: Observatórium Lomnický štít - meteorológia a slnečná
astrofyzika Title: Observatórium Lomnický štít - meteorológia
a slnečná astrofyzika Title: Lomnický štít Observatory -
    meteorology and solar astrophysics.
Authors: Rybák, J.; Mačura, R.; Bendík, P.; Bochníček, O.;
   Horecká, V.
Bibcode: 2010nspm.conf..191R
Altcode:
  The paper presents statistical results obtained in the analysis of
  long-term series of meteorological observations of temperature, wind
  speed and wind direction, and daylight length that were measured
  in the period 1964-2009 at the SHMI Meteorological Observatory
  located at the Lomnický štít mountain peak. In relation to these
  meteorological data, the contribution also presents statistical results
  for time scales of various types of solar prominence and solar corona
  observations at the Lomnický štít Astronomical Observatory in the
  period 1980-2009. The obtained results were used to characterize the
  observatory from meteorological perspective presenting mainly the
  range and quality of observing conditions suitable for solar activity
  observations. The results show that observing conditions allow for
  observation of prominences in approximately one third of the days in
  a year, and observation of the emission corona in approximately one
  fifth of the days in a year. The contribution also documents the use of
  the obtained results in preparation of new post-focal instruments for
  solar corona monitoring, i. e. the coronal multipolarimeter (COMP-S)
  that is at present under construction. Effects of local warming of
  the Earth's atmosphere are tested in a statistical analysis of the
  meteorological data collected in the period 1964-2009. In this period,
  a marked local warming occured at Lomnický štít with increases in
  the minimal daily temperature 0.90°C and maximal daily temperature
  1.84°C, and the mean value of these quantities raising by 1.21°C.

Title: Dynamika fotosférických jasných bodov v G-páse odvodená
použitím dvoch plne automatických algoritmov Title: Dynamika
    fotosférických jasných bodov v G-páse odvodená použitím dvoch
plne automatických algoritmov Title: Dynamics of photospheric bright
    points in G-band derived from two fully automated algorithms.
Authors: Bodnárová, M.; Rybák, J.; Hanslmeier, A.; Utz, D.
Bibcode: 2010nspm.conf...25B
Altcode:
  Concentrations of small-scale magnetic field in the solar photosphere
  can be identified in the G-band of the solar spectrum as bright
  points. Studying the dynamics of the bright points in the G-band
  (BPGBs) can also help in addressing many issues related to the
  problem of the solar corona heating. In this work, we have used
  a set of 142 specled images in the G-band taken by the Dutch Open
  Telescope (DOT) on 19 October 2005 to make a comparison of two fully
  automated algorithms identifying BPGBs: an algorithm developed by Utz
  et al. (2009, 2010), and an algorithm developed following the work
  of Berger et al. (1995, 1998). We then followed in time and space
  motion of the BPGBs identified by both algorithms and constructed the
  distributions of their lifetimes, sizes and speeds. The results show
  that both algorithms give very similar results for the BPGB lifetimes
  and speeds, but their results vary significantly for the sizes of the
  identified BPGBs. This difference is due to the fact that in the case of
  the Berger et al. identification algorithm no additional criteria were
  applied to constrain the allowed BPGB sizes. As a result in further
  studies of the BPGB dynamics we will prefer to use the Utz algorithm
  to identify and track BPGBs.

Title: North-south asymmetry of Ca II K regions determined from OAUC
spectroheliograms: 1996 - 2006
Authors: Dorotovič, I.; Rybák, J.; Garcia, A.; Journoud, P.
Bibcode: 2010nspm.conf...58D
Altcode:
  The solar activity (SA) evolution levels are not identical in the
  northern and southern Sun's hemispheres. This fact was repeatedly
  confirmed in the past by the analysis of a number of long-term
  observations of various SA indices in individual atmospheric layers
  of the Sun and in different bandwidths. The north-south asymmetry
  (NSA) is thus a significant tool in investigation of long-term SA
  variations. This paper presents a software tool to determine the
  NSA of the area of bright chromospheric plages, as measured in the
  Ca II K3 spectroheliograms registered since 1926 in the Observatário
  Astronómico da Universidade de Coimbra, Portugal, as well as evolution
  of sizes of these areas in the period 1996 - 2006. The algorithm
  of the program is limited to determining the total area of bright
  features in the Ca II K3 emission line based on the definition of the
  threshold value for relative brightness and, therefore, it does not
  resolve brightness of individual chromospheric features. A comparison
  and cross-correlation of this NSA with the NSAs found for the sunspots
  and coronal green line brightness have been added. In the near future
  we intend to 1) determine the NSA of the area of bright chromospheric
  Ca II K3 regions back to the year 1926, and 2) compare the evolution
  of the surface area of these regions in the period 1970-2006 with the
  evolution of the magnetic index obtained at Mt. Wilson Observatory,
  which would also help in setting up a proxy reconstruction of the
  magnetic index back to 1926. Since 2007 new spectroheliograms have been
  recorded using a CCD camera and, therefore, in the future we will also
  address this issue for the period 2007 - present.

Title: Slnečná aktivita a kozmické 'iarenie: magnetické pole
Slnka a úroveň kozmického žiarenia Title: Slnečná aktivita a
kozmické 'iarenie: magnetické pole Slnka a úroveň kozmického
žiarenia Title: Solar activity and cosmic radiation: Sun's magnetic
    field and cosmic radiation levels.
Authors: Bodnárová, M.; Rybák, J.; Gömöry, P.; Kudela, K.
Bibcode: 2010nspm.conf..175B
Altcode:
  In this work we have analyzed the correlation of the Sun's magnetic
  activity and cosmic radiation levels during the period 1951-2004. As a
  solar magnetic activity indicator, affecting the cosmic radiation, we
  have chosen open magnetic field configurations which we characterized
  by an open magnetic flux factor (OMFF). The OMFF was calculated from
  the intensity measurements of the green coronal line. In calculations
  leading to the relation between the OMFF and galactic cosmic radiation
  (GCR) levels the cross-correlation of these datasets was used. The goal
  of this contribution was to find mainly time-dependent changes in the
  evolution of the OMFF and GCR correlation. In order to do so,besides
  the correlation calculations based on the long time series of the
  OMFF and GCR data covering the entire period 1951-2004 we have also
  calculated the correlation of the OMFF and GCR data from shorter periods
  (180 days). We have found that the cross-correlation evolution varies
  depending on the phase of the solar cycle. During the minimum the
  evolution is characterized by conspicuous periodicity with a period
  ~ 14 days and the cross-correlation function takes statistically
  significant values. During the maximum the period of the variations
  is not clear and the cross-correlation function takes low values that
  are not statistically significant.

Title: Multiwavelength Imaging and Spectroscopy of Chromospheric
    Evaporation in an M-class Solar Flare
Authors: Veronig, A. M.; Rybák, J.; Gömöry, P.; Berkebile-Stoiser,
   S.; Temmer, M.; Otruba, W.; Vršnak, B.; Pötzi, W.; Baumgartner, D.
Bibcode: 2010ApJ...719..655V
Altcode: 2010arXiv1007.0930V
  We study spectroscopic observations of chromospheric evaporation mass
  flows in comparison with the energy input by electron beams derived
  from hard X-ray (HXR) data for the white-light M2.5 flare of 2006 July
  6. The event was captured in high-cadence spectroscopic observing mode
  by SOHO/CDS combined with high-cadence imaging at various wavelengths
  in the visible, extreme ultraviolet, and X-ray domain during the joint
  observing campaign JOP171. During the flare peak, we observe downflows
  in the He I and O V lines formed in the chromosphere and transition
  region, respectively, and simultaneous upflows in the hot coronal
  Si XII line. The energy deposition rate by electron beams derived
  from RHESSI HXR observations is suggestive of explosive chromospheric
  evaporation, consistent with the observed plasma motions. However, for
  a later distinct X-ray burst, where the site of the strongest energy
  deposition is exactly located on the Coronal Diagnostics Spectrometer
  (CDS) slit, the situation is intriguing. The O V transition region
  line spectra show the evolution of double components, indicative of
  the superposition of a stationary plasma volume and upflowing plasma
  elements with high velocities (up to 280 km s<SUP>-1</SUP>) in single
  CDS pixels on the flare ribbon. However, the energy input by electrons
  during this period is too small to drive explosive chromospheric
  evaporation. These unexpected findings indicate that the flaring
  transition region is much more dynamic, complex, and fine structured
  than is captured in single-loop hydrodynamic simulations.

Title: Radio spectra generated during coalescence processes of
    plasmoids in a flare current sheet
Authors: Karlický, M.; Bárta, M.; Rybák, J.
Bibcode: 2010A&A...514A..28K
Altcode:
  <BR /> Aims: Motivated by observations of the drifting pulsating
  structures (DPSs) in solar radio spectra, we study the electromagnetic
  (radio) emission generated during tearing and coalescence processes in a
  flare current sheet. <BR /> Methods: For numerical simulations, we used
  a 2.5-D particle-in-cell electromagnetic relativistic code. Numerical
  data were analyzed by the wavelet methods. <BR /> Results: It is found
  that the electromagnetic emission is generated during a coalescence of
  plasmoids, and it has a quasi-periodic character. Detailed analysis
  reveals that the electromagnetic emission is produced around the
  interacting plasmoids just before their coalescence into a larger
  one. The period in variations of electromagnetic emission corresponds
  to that of magnetic field at the same region. Reflections of the
  electromagnetic waves between interacting plasmoids are recognized. The
  computed and observed periodicities are discussed. The similarity of
  the DPSs with some radio bursts observed during star flares indicates
  a broader applicability for this model.

Title: The SECIS instrument on the Lomnický Peak Observatory
Authors: Ambróz, J.; Radziszewski, K.; Rudawy, P.; Rybák, J.;
   Phillips, K. J. H.
Bibcode: 2010CoSka..40....5A
Altcode: 2010arXiv1004.3454A
  Heating mechanisms of the solar corona will be investigated at the <P
  />high-altitude solar observatory Lomnicky Peak of the Astronomical
  Institute <P />of SAS (Slovakia) using its mid-size Lyot coronagraph
  and post-focal <P />instrument SECIS provided by Astronomical Institute
  of the University of <P />Wrocław (Poland). The data will be studied
  with respect to the energy <P />transport and release responsible
  for heating the solar corona to <P />temperatures of mega-Kelvins. In
  particular investigations will be focused <P />on detection of possible
  high-frequency MHD waves in the solar corona. The <P />scientific
  background of the project, technical details of the SECIS system <P
  />modified specially for the Lomnicky Peak coronagraph, and inspection
  of the <P />test data are described in the paper.

Title: Manifestations of the North - South Asymmetry in the
    Photosphere and in the Green Line Corona
Authors: Sýkora, J.; Rybák, J.
Bibcode: 2010SoPh..261..321S
Altcode:
  The north - south asymmetries (NSA) of three solar activity indices
  are derived and mutually compared over a period of more than five solar
  cycles (1945 - 2001). A catalogue of the hemispheric sunspot numbers,
  the data set of the coronal green line brightness developed by us,
  and the magnetic flux derived from the NSO/KP data (1975 - 2001)
  are treated separately within the discrete low- and mid-latitude
  zones (5° - 30°, 35° - 60°). The calculated autocorrelations,
  cross-correlations, and regressions between the long-term NSA data
  sets reveal regularities in the solar activity phenomenon. Namely, the
  appearance of a distinct quasi-biennial oscillation (QBO) is evident
  in all selected activity indices. Nevertheless, a smooth behavior of
  QBO is derived only when sufficient temporal averaging is performed
  over solar cycles. The variation in the significance and periodicity of
  QBO allows us to conclude that the QBO is not persistent over the whole
  solar cycle. A similarity in the photospheric and coronal manifestations
  of the NSA implies that their mutual relation will also show the QBO. A
  roughly two-year periodicity is actually obtained, but again only after
  significant averaging over solar cycles. The derived cross-correlations
  are in fact variable in degree of correlation as well as in changing
  periodicity. A clear and significant temporal shift of 1 - 2 months
  in the coronal manifestation of the magnetic flux asymmetry relative
  to the photospheric manifestation is revealed as a main property of
  their mutual correlation. This shift can be explained by the delayed
  large-scale coronal manifestation in responding to the emergence of
  the magnetic flux in the photosphere. The reliability of the derived
  results was confirmed by numerical tests performed by selecting
  different numerical values of the used parameters.

Title: Magnetic loop emergence within a granule
Authors: Gömöry, P.; Beck, C.; Balthasar, H.; Rybák, J.; Kučera,
   A.; Koza, J.; Wöhl, H.
Bibcode: 2010A&A...511A..14G
Altcode: 2009arXiv0910.4449G
  <BR /> Aims: We investigate the temporal evolution of magnetic
  flux emerging within a granule in the quiet-Sun internetwork at
  disk center. <BR /> Methods: We combined IR spectropolarimetry of
  high angular resolution performed in two Fe i lines at 1565 nm with
  speckle-reconstructed G-band imaging. We determined the magnetic
  field parameters by a LTE inversion of the full Stokes vector using
  the SIR code, and followed their evolution in time. To interpret
  the observations, we created a geometrical model of a rising loop in
  3D. The relevant parameters of the loop were matched to the observations
  where possible. We then synthesized spectra from the 3D model for a
  comparison to the observations. <BR /> Results: We found signatures of
  magnetic flux emergence within a growing granule. In the early phases,
  a horizontal magnetic field with a distinct linear polarization signal
  dominated the emerging flux. Later on, two patches of opposite circular
  polarization signal appeared symmetrically on either side of the linear
  polarization patch, indicating a small loop-like structure. The mean
  magnetic flux density of this loop was roughly 450 G, with a total
  magnetic flux of around 3 × 10<SUP>17</SUP> Mx. During the ~12 min
  episode of loop occurrence, the spatial extent of the loop increased
  from about 1 to 2 arcsec. The middle part of the appearing feature
  was blueshifted during its occurrence, supporting the scenario of an
  emerging loop. There is also clear evidence for the interaction of
  one loop footpoint with a preexisting magnetic structure of opposite
  polarity. The temporal evolution of the observed spectra is reproduced
  to first order by the spectra derived from the geometrical model. During
  the phase of clearest visibility of the loop in the observations,
  the observed and synthetic spectra match quantitatively. <BR />
  Conclusions: The observed event can be explained as a case of flux
  emergence in the shape of a small-scale loop. The fast disappearance
  of the loop at the end could possibly be due to magnetic reconnection.

Title: Dynamics of isolated magnetic bright points derived from
    Hinode/SOT G-band observations
Authors: Utz, D.; Hanslmeier, A.; Muller, R.; Veronig, A.; Rybák,
   J.; Muthsam, H.
Bibcode: 2010A&A...511A..39U
Altcode: 2009arXiv0912.1965U
  Context. Small-scale magnetic fields in the solar photosphere can
  be identified in high-resolution magnetograms or in the G-band as
  magnetic bright points (MBPs). Rapid motions of these fields can
  cause magneto-hydrodynamical waves and can also lead to nanoflares by
  magnetic field braiding and twisting. The MBP velocity distribution is
  a crucial parameter for estimating the amplitudes of those waves and
  the amount of energy they can contribute to coronal heating. <BR />
  Aims: The velocity and lifetime distributions of MBPs are derived from
  solar G-band images of a quiet sun region acquired by the Hinode/SOT
  instrument with different temporal and spatial sampling rates. <BR
  /> Methods: We developed an automatic segmentation, identification
  and tracking algorithm to analyse G-Band image sequences to obtain
  the lifetime and velocity distributions of MBPs. The influence of
  temporal/spatial sampling rates on these distributions is studied and
  used to correct the obtained lifetimes and velocity distributions for
  these digitalisation effects. <BR /> Results: After the correction of
  algorithm effects, we obtained a mean MBP lifetime of (2.50 ± 0.05)
  min and mean MBP velocities, depending on smoothing processes, in
  the range of (1-2) km~s<SUP>-1</SUP>. Corrected for temporal sampling
  effects, we obtained for the effective velocity distribution a Rayleigh
  function with a coefficient of (1.62 ± 0.05) km~s<SUP>-1</SUP>. The
  x- and y-components of the velocity distributions are Gaussians. The
  lifetime distribution can be fitted by an exponential function.

Title: G-band to Blue-Continuum Excess as quasi total field strength
    magnetogram
Authors: Utz, D.; Hanslmeier, A.; Veronig, A.; Rybák, J.; Muller,
   R.; Muthsam, H.
Bibcode: 2010CEAB...34...13U
Altcode:
  The dynamics of the solar plasma is driven by strong localized magnetic
  fields. It is well known that activity like flares and CMEs are related
  to the dissipation and reconnection of these magnetic fields. These
  energetic releases influence and make up the so called space weather. It
  is therefore of vital importance to get a deeper understanding of the
  magnetic fields of the Sun. To get this insights, it is crucial to
  obtain information on the magnetic fields with spatial and temporal
  resolutions as high as possible. In this paper we outline an easy to
  apply method to obtain quasi total magnetic field strength magnetograms
  out of two simple filtergrams (blue continuum and G-band). We will
  present our simple approach and the first results of this method and
  give finally an outlook what has to be done in the future.

Title: Dynamics of G-band bright points derived using two fully
    automated algorithms
Authors: Bodnárová, M.; Utz, D.; Rybák, J.; Hanslmeier, A.
Bibcode: 2010CEAB...34...25B
Altcode:
  Small-scale magnetic field concentrations (∼ 1 kG) in the solar
  photosphere can be identified in the G-band of the solar spectrum
  as bright points. Study of the G-band bright points (GBPs) dynamics
  can help us in solving several questions related also to the coronal
  heating problem. Here a set of 142 G-band speckled images obtained
  using the Dutch Open Telescope (DOT) on October 19, 2005 are used to
  compare identification of the GBPs by two different fully automated
  identification algorithms: an algorithm developed by Utz et al. (2009a,
  2009b) and an algorithm developed according to papers of Berger et
  al. (1995, 1998). Temporal and spatial tracking of the GBPs identified
  by both algorithms was performed resulting in distributions of
  lifetimes, sizes and velocities of the GBPs. The obtained results show
  that both algorithms give very similar values in the case of lifetime
  and velocity estimation of the GBPs, but they differ significantly
  in case of estimation of the GBPs sizes. This difference is caused
  by the fact that we have applied no additional exclusive criteria on
  the GBPs identified by the algorithm based on the work of Berger et
  al. (1995, 1998). Therefore we conclude that in a future study of the
  GBPs dynamics we will prefer to use the Utz's algorithm to perform
  identification and tracking of the GBPs in G-band images.

Title: Multi-wavelength fine structure and mass flows in solar
    microflares
Authors: Berkebile-Stoiser, S.; Gömöry, P.; Veronig, A. M.; Rybák,
   J.; Sütterlin, P.
Bibcode: 2009A&A...505..811B
Altcode:
  Aims: We study the multi-wavelength characteristics at high spatial
  resolution, as well as chromospheric evaporation signatures of solar
  microflares. To this end, we analyze the fine structure and mass
  flow dynamics in the chromosphere, transition region and corona of
  three homologous microflares (GOES class &lt;A9/0.7 with/without
  background), which occurred on July 4, 2006 in AR 10898. <BR
  />Methods: A multi-wavelength analysis using temporally and spatially
  highly resolved imaging data from the Dutch open telescope (Hα,
  Ca ii H), the transition region and coronal explorer (17.1 nm),
  the extreme-ultraviolet imaging telescope (19.5 nm), and the Reuven
  Ramaty high energy solar spectroscopic imager (≳3 keV) was carried
  out. EUV line spectra provided by the coronal diagnostic spectrometer
  are searched for Doppler shifts in order to study associated
  plasma flows at chromospheric (He i, T∼3.9× 10<SUP>4</SUP> K),
  transition region (e.g. O v, T∼ 2.6× 10<SUP>5</SUP> K), and
  coronal temperatures (Si xii, T∼ 2× 10<SUP>6</SUP> K). RHESSI
  X-ray spectra provide information about non-thermal electrons. <BR
  />Results: The multi-wavelength appearance of the microflares is in
  basic agreement with the characteristics of large flares. For the
  first event, a complex flare sequence is observed in TRACE 17.1 nm
  images (T≈ 1 MK), which show several brightenings, narrow loops
  of enhanced emission, and an EUV jet. EIT 19.5 nm data (T≈ 1.5 MK)
  exhibit similar features for the third event. DOT measurements show
  finely structured chromospheric flare brightenings for all three events,
  loop-shaped fibrils of increased emission between Hα brightenings, as
  well as a similar feature in Ca ii. For all three events, a RHESSI X-ray
  source (3-8 keV, T ≳ 10 MK) is located in between two chromospheric
  brightenings situated in magnetic flux of opposite polarity. We find
  the flow dynamics associated with the events to be very complex. In
  the chromosphere and transition region, CDS observed downflows for
  the first (v ≲ 40 km s<SUP>-1</SUP>), and upflows for the second
  event (v ≲ 40 km s<SUP>-1</SUP>). During the third microflare, we
  find upflows of ≲ 20 km s<SUP>-1</SUP> and also weak downflows of
  ≲20 km s<SUP>-1</SUP> in two separate brightenings. For all three
  microflares, multi-component fitting is needed for several profiles
  of He i, O v, and Ne vi lines observed at the flare peaks, which
  indicate spatially unresolved, oppositely directed flows of ≲180
  km s<SUP>-1</SUP>. We interpret these flows as twisting motions of
  the flare loops. Loop-shaped fibrils in between Hα brightenings
  showing opposite flow directions (v≈5 km s<SUP>-1</SUP>) are also
  observed in DOT Hα Dopplergrams. RHESSI X-ray spectra show evidence
  of non-thermal bremsstrahlung for two of the three microflares. The
  electron beam flux density deposited in the chromosphere for these
  events is estimated to straddle the threshold heating flux between
  gentle and explosive evaporation. <P />Appendix A and the movie are
  only available in electronic form at http://www.aanda.org

Title: ``Drifting tadpoles'' in wavelet spectra of decimetric radio
    emission of fiber bursts
Authors: Mészárosová, H.; Karlický, M.; Rybák, J.; Jiřička, K.
Bibcode: 2009A&A...502L..13M
Altcode:
  Aims: The solar decimetric radio emission of fiber bursts was
  investigated searching for the “drifting tadpole” structures
  proposed by theoretical studies. <BR />Methods: Characteristic periods
  with the tadpole pattern were searched for in the radio flux time
  series by wavelet analysis methods. <BR />Results: For the first time,
  we have found drifting tadpoles in the wavelet spectra of the decimetric
  radio emission associated with the fiber bursts observed in July 11,
  2005. These tadpoles were detected at all radio frequencies in the
  1602-1780 MHz frequency range. The characteristic period of the wavelet
  tadpole patterns was found to be 81.4 s and the frequency drift of the
  tadpole heads is -6.8 MHz s<SUP>-1</SUP>. These tadpoles are interpreted
  as a signature of the magnetoacoustic wave train moving along a dense
  flare waveguide and their frequency drift as a motion of the wave
  train modulating the radio emission produced by the plasma emission
  mechanism. Using the Aschwanden density model of the solar atmosphere,
  only low values of the Alfvén speed and the magnetic field strength
  in the loop guiding this wave train were derived which indicates a
  neutral current sheet as the guiding structure. The present analysis
  supports the model of fiber bursts based on whistler waves.

Title: Analyses of magnetic field structures for active region 10720
    using a data-driven 3D MHD model
Authors: Wu, S. T.; Wang, A. H.; Gary, G. Allen; Kucera, Ales; Rybak,
   Jan; Liu, Yang; Vrśnak, Bojan; Yurchyshyn, Vasyl
Bibcode: 2009AdSpR..44...46W
Altcode:
  In order to understand solar eruptive events (flares and CMEs) we
  need to investigate the changes at the solar surface. Thus, we use
  a data-driven, three-dimensional magnetohydrodynamic (MHD) model to
  analyze a flare and coronal mass ejection productive active region,
  AR 10720 on January 15, 2005. The measured magnetic field from Big
  Bear Solar Observatory (BBSO) digital vector magnetograph (DGVM) was
  used to model the non-potential coronal magnetic field changes and the
  evolution of electric current before and after the event occurred. The
  numerical results include the change of magnetic flux ( Φ), the net
  electric current ( I<SUB>N</SUB>), the length of magnetic shear of the
  main neutral line ( L<SUB>ss</SUB>), the flux normalized measure of
  the field twist (α={μI<SUB>N</SUB>}/{Φ}) with μ being the magnetic
  permeability. The current helicity ( H<SUB>c</SUB>) injected into the
  corona and the photospheric surface velocity are also computed. The
  characteristic parameters of the buildup process before the event and
  the decay process after the event are investigated and the amount of
  magnetic energy converted to drive the event is estimated.

Title: Tadpoles in Wavelet Spectra of a Solar Decimetric Radio Burst
Authors: Mészárosová, H.; Karlický, M.; Rybák, J.; Jiřička, K.
Bibcode: 2009ApJ...697L.108M
Altcode:
  In the solar decimetric type IV radio event observed on 2001 June 13,
  we have found wavelet tadpole patterns for the first time. They were
  detected simultaneously at all radio frequencies in the 1.1-4.5 GHz
  frequency range. The characteristic period of the wavelet tadpole
  patterns was found to be 70.9 s. The parameters of the tadpoles on
  different frequencies are very similar and the correlations between
  individual radio fluxes are high. These tadpoles are interpreted as a
  signature of the magnetoacoustic wave train moving along the flare loop
  through the radio source and modulating its gyrosynchrotron emission.

Title: Coronal fast wave trains of the decimetric type IV radio
    event observed during the decay phase of the June 6, 2000 flare
Authors: Mészárosová, H.; Sawant, H. S.; Cecatto, J. R.; Rybák, J.;
   Karlický, M.; Fernandes, F. C. R.; de Andrade, M. C.; Jiřička, K.
Bibcode: 2009AdSpR..43.1479M
Altcode:
  The 22 min long decimetric type IV radio event observed during the
  decay phase of the June 6, 2000 flare simultaneously by the Brazilian
  Solar Spectroscope (BSS) and the Ondřejov radiospectrograph in
  frequency range 1200-4500 MHz has been analyzed. We have found that
  the characteristic periods of about 60 s belong to the long-period
  spectral component of the fast wave trains with a tadpole pattern
  in their wavelet power spectra. We have detected these trains in
  the whole frequency range 1200-4500 MHz. The behavior of individual
  wave trains at lower frequencies is different from that at higher
  frequencies. These individual wave trains have some common as well as
  different properties. In this paper, we focus on two examples of wave
  trains in a loop segment and the main statistical parameters in their
  wavelet power and global spectra are studied and discussed.

Title: Observations of Chromospheric Evaporation Flows in RHESSI
    Microflares
Authors: Berkebile-Stoiser, S.; Gömöry, P.; Veronig, A.; Rybák, J.
Bibcode: 2009CEAB...33..169B
Altcode:
  We present the analysis of two homologous microflares of GOES class
  A9 with respect to mass flows in the chromosphere and transition
  region. Both events show non-thermal emission (evidence for beamed
  electrons) in RHESSI X-ray spectra. As outlined by observations of
  the Coronal Diagnostic Spectrometer, we find for the first event
  downflows in the He I, O V and Ne VI line reaching speeds up to 40
  km s^{-1} at the position of chromospheric flare brightenings. On
  the other hand, upflows with velocities ≲40 km^{-1} are observed
  for the second microflare. <P />According to hydrodynamic flare
  simulations, the non-thermal electron energy density F deposited in
  the chromosphere determines if chromospheric evaporation is `gentle' or
  `explosive'. Thus, we derive rough estimates for F in our microflares
  and compare the results to the observed CDS flow properties.

Title: Multi-wavelength Observations of Microflares Near an Active
    Region
Authors: Bein, B.; Veronig, A.; Rybak, J.; Gömöry, P.;
   Berkebile-Stoiser, S.; Sütterlin, P.
Bibcode: 2009CEAB...33..179B
Altcode:
  We study the multi-wavelength characteristics of a microflaring active
  region (AR 10898) near disc centre. The analysed data were from the
  4^{th} of July 2006, and were recorded by DOT (Hα, Ca II H), RHESSI
  (X-rays), TRACE (EUV) and SOHO/MDI (magnetograms). The identified
  microflare events were studied with respect to their magnetic field
  configuration and their multi-wavelength time evolution.

Title: Solar Convection and Oscillation Interaction
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.;
   Gömöry, P.
Bibcode: 2009CEAB...33...51H
Altcode:
  In this paper we investigate bisectors of solar photospheric lines. The
  bisectors reflect vertical velocity gradients over the height of line
  formation and therefore reveal important information about the dynamics
  in these layers. Their shape and shift is influenced by (a) convective
  motions, (b) oscillatory motions that can act differently at different
  photospheric heights. The bisectors are selected from different
  locations that show mainly a granular evolution or an intergranular
  evolution. Two selection criteria were applied: continuum intensity
  (enhanced for granular bisectors, reduced for intergranular bisectors),
  and full width at half maximum values (enhanced for intergranular
  bisectors). The results demonstrate how oscillatory motions influence
  the bisectors as a whole. In the example given a smaller amplitude of
  oscillations over intergranular areas is indicated.

Title: Observational Evidence for Shocks in the Solar Photosphere -
    New TESOS/VTT Results
Authors: Rybak, J.; Kucera, A.; Hanslmeier, A.; Woehl, H.;
   Wedemeyer-Boehm, S.; Steiner, O.
Bibcode: 2008ESPM...12.2.36R
Altcode:
  High-resolution spectroscopic observations recently acquired with the
  TESOS spectrometer at the Vacuum Tower Telescope (VTT, Observatorio
  del Teide, Tenerife) are used to test predictions regarding strongly
  dynamic events in the photosphere as obtained from three-dimensional
  numerical simulations with the CO5BOLD-code. <P />Time series of
  two-dimensional maps of the Fe I 543.4 nm spectral line profile at
  different centre-to-limb positions are investigated in a statistical
  sense by comparing the distributions of individual spectral parameters
  derived from observations with the corresponding distributions
  from synthesized spectra calculated with the LINFOR3D code from
  the simulations. Appropriate degradation of the synthesized spectra
  was applied in order to take the limited spatial resolution of the
  telescope, seeing effects, and the scattered instrumental light into
  account. <P />At the actual spatial resolution of 0.5 arc sec, the
  statistics show that signatures of the photospheric dynamics, including
  the most dynamical events like occasional supersonic flows of plasma in
  the nearly horizontal direction, are very similar in both observations
  and simulations. <P />Discrepancies are found only for those spectral
  parameters (residual line intensity, Doppler line core shifts), which
  are affected by non-LTE effects, since non-LTE effects are not taken
  into account in the synthesis of the Fe I 543.4nm spectral line.

Title: Flare Generated Coronal Fast Wave Trains of Decimetric Radio
    Pulsations
Authors: Meszarosova, H.; Sawant, H. S.; Cecatto, J. R.; Rybak, J.;
   Karlicky, M.; Fernandes, F. C. R.; Jiricka, K.; Andrade, M. C.
Bibcode: 2008ESPM...122.105M
Altcode:
  The 22 minutes lasting interval of broadband dm-radio pulsations
  observed simultaneously during a decay phase of the June 6, 2000 flare
  by the Brazilian Solar Spectroscope (BSS) and Ondrejov radiospectrograph
  in frequency range 1200-4500 MHz has been analyzed. We have realized
  that dominant periods (32-64 s) belong to fast wave trains with a
  tadpole pattern in their wavelet power spectra. The whole time interval
  contains series of about 4 wave trains. These trains propagate in
  whole frequency range 1200-4500 MHz. The propagation of individual
  trains at lower levels of the solar atmosphere (higher frequencies) is
  different from propagation of individual trains at higher ones (lower
  frequencies). The wave trains at the same frequencies but in different
  time subintervals have some common as well as different properties. The
  main statistical parameters (periodical, quasi-periodical and decay
  phase) of these wave trains in their wavelet power spectra have been
  studied and the first results will be presented and discussed.

Title: Multi-wavelength Observations of Dynamic Fibrils in the Upper
    Photosphere and Chromosphere
Authors: Kucera, A.; Beck, Ch.; Gomory, P.; Koza, J.; Woehl, H.;
   Rybak, J.
Bibcode: 2008ESPM...12.2.52K
Altcode:
  Spatial and temporal evolution of dynamic fibrils (DF) as well as
  coupling with photospheric features was investigated. <P />The
  main target were remnants in the active region 10997 on May 28,
  2008. We used about 1 hour series of multi wavelength simultaneous
  observations of the DFs and corresponding photospheric features. The
  observations were performed with the german Vacuum Tower Telescope
  equipped with several post-focus instruments. Namely: TESOS (Triple
  Etalon SOlar Spectrometer) instrument was used in polarimetric mode
  (VIP=Visual Imaging Polarimeter) to register 2D spectra of the DFs in
  H-alpha line and in magnetically sensitive Fe I 630.2 nm line. TIP
  (Tenerife Infrared Polarimeter) mounted on the Echelle spectrograph
  was used for spectropolarimetric observations of two neutral iron
  lines at 1.56 micrometers. We scanned 2D area 80" x 5", producing
  thus 2D maps of intensity, velocity and magnetic field of the low
  photosphere under the chromospheric fibril field. <P />Additionally
  G-band and H-alpha images were registered with high cadence and
  the supporting data from the TRACE satellite (17.1 nm, WL, Lyman
  alpha line and 160 nm continuum) are also available. After careful
  spatial coalignment of 2D maps we first selected numerous DFs in the
  H-alpha images. Then we investigated temporal evolution of those DFs
  concerning changes of their dimensions, positions and fluctuations
  and correlated these characteristics with temporal evolution of the
  intensities, velocities and magnetic field characteristics observed in
  the spatially corresponding photosphere. The poster demonstrates the
  complex observations, data reduction and coalignment and preliminary
  results on coupling between DFs and underlying photospheric features.

Title: Observation of Turbulence in Solar Surface Convection:
    I. Line Parameter Correlations
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 2008SoPh..249..293H
Altcode: 2008SoPh..tmp...88H
  By using slit observations of solar photospheric lines shifted by 0.4
  arcsec, a 2D field on the Sun was scanned to obtain a 16-minute time
  series of 2D line-parameter variations. The aim was to investigate in
  detail the occurrence of turbulence that can be measured by line-width
  variations extracted from the line profiles. The continuum-intensity
  variation served as a proxy for granular (bright) and intergranular
  (dark) areas. The results show that turbulence is not limited to
  the intergranular space but is also produced by horizontal motions
  that may become supersonic, leading to turbulence. These motions
  lead to brightenings, as predicted by theoretical models. Thus,
  enhanced line-width variations are found to occur in both bright and
  dark areas. A Sobel filter served to detect the areas where strong
  gradients in the line parameters occur. By applying this filter to the
  different line-parameter variations over the 2D field observed, we can
  determine whether there exists a similarity of these strong-gradient
  patterns with other parameters that characterize granular motions such
  as intensity variations or velocity fluctuations.

Title: Acceleration in Fast Halo CMEs and Synchronized Flare HXR
    Bursts
Authors: Temmer, M.; Veronig, A. M.; Vršnak, B.; Rybák, J.; Gömöry,
   P.; Stoiser, S.; Maričić, D.
Bibcode: 2008ApJ...673L..95T
Altcode:
  We study two well-observed, fast halo CMEs, covering the full CME
  kinematics including the initiation and impulsive acceleration phase,
  and their associated flares. We find a close synchronization between the
  CME acceleration profile and the flare energy release as indicated by
  the RHESSI hard X-ray flux onsets, as well as peaks occur simultaneously
  within 5 minutes. These findings indicate a close physical connection
  between both phenomena and are interpreted in terms of a feedback
  relationship between the CME dynamics and the reconnection process in
  the current sheet beneath the CME.

Title: Period variations of radio pulsations observed during decay
    phase of the June 06, 2000 flare
Authors: Sawant, Hanumant; Meszarosova, Hana; Cecatto, José;
   Karlicky, Marian; Rybak, Jan; Fernandes, Francisco; Andrade, Maria;
   Jiricka, Karel
Bibcode: 2008cosp...37.2758S
Altcode: 2008cosp.meet.2758S
  The 22 minutes lasting interval of broadband dm-radio pulsations
  observed during decay phase of the June 6, 2000 flare by Brazilian
  Solar Spectroscope (BSS) and Ondrejov radiospectrograph in frequency
  range 1200-4500 MHz have been analyzed for its complex temporal
  variability. To understand the global relationship between radio
  fluxes on lower and higher frequencies and to recognize different
  emission mechanisms, we have made the cross-correlation of the radio
  fluxes at different frequencies during time intervals under study. We
  have realized that the dominant periods are not spread during whole
  22 minutes time interval but their appearance is concentrated into 7
  shorter time subintervals that we have then studied in detail. These
  subintervals last 9-33 s, on average 21 s. The pulsations inside the
  subintervals usually have higher intensity than the other ones and
  characteristic dominant periods of these quasi-regular pulsations are
  0.5-78.8 s. We were interested in possible differences among dominant
  periods of individual time intervals as well as between the periods
  at frequencies below and above 2000 MHz. Periods &gt; 60 s are rather
  rare. The periods &lt; 40 s occur more frequently at frequencies below
  2000 MHz than at frequencies above 2000 MHz. Occurrence of the periods
  &gt; 40 s is similar at frequencies below and above 2000 MHz. Results
  are compared with TRACE and EIT/SOHO images and discussed in framework
  of multi-scaling flare loop interactions.

Title: North-South Asymmetry of Ca II K Plages
Authors: Dorotovič, I.; Journoud, P.; Rybák, J.; Sýkora, J.
Bibcode: 2007ASPC..368..527D
Altcode:
  The level and evolution of solar activity is not identical in the
  northern and southern Sun's hemispheres. This fact was repeatedly
  confirmed in the past by analysis of a number of long-term observations
  of various solar activity indices. Presently, it seems that the
  north-south (N-S) asymmetry represents quite specific, independent
  and very promising tool to advance in analysis of the long-term solar
  activity variations. This paper is focused to give a software tool for
  estimation of the N-S asymmetry in the area of bright chromospheric
  plages, as measured on the Ca II K<SUB>3</SUB> spectroheliograms
  registered since 1926 in the Observatório Astronómico da Universidade
  de Coimbra, Portugal. In fact, studies of the N-S asymmetry of just
  this phenomenon are rare, namely due to absence of technique allowing
  reliable quantitative estimations of the Ca II K<SUB>3</SUB> plages
  parameters. Our algorithm is also partially limited, it provides the
  area of bright Ca II K<SUB>3</SUB> emission structures, but it does
  not perceive differences in the brightness of individual chromospheric
  features. As for the N-S asymmetry of the chromospheric plages alone,
  we present here a sample of its estimation only. Its behavior during
  the first half of 2000 year is provided to illustrate application of
  the software developed. A comparison and cross-correlation with the N-S
  asymmetries found for the sunspots and corona green line brightness is
  added. We intend to discuss the results of more extensive analysis of
  the chromospheric plages N-S asymmetry as soon as a sufficiently long
  time series of the Ca II K<SUB>3</SUB> Coimbra spectroheliograms will
  be digitized and processed.

Title: Temporal Variations in Fibril Orientation
Authors: Koza, J.; Sütterlin, P.; Kučera, A.; Rybák, J.
Bibcode: 2007ASPC..368..115K
Altcode: 2007astro.ph..3733K
  We measure variations in orientation of fourteen dynamic fibrils as
  a function of time in a small isolated plage and nearby network using
  a 10-min time sequence of Hα filtergrams obtained by the Dutch Open
  Telescope. We found motions with average angular velocities of the
  order of 1 deg min<SUP>-1</SUP> suggesting systematic turning from
  one limit position to another, particularly apparent in the case of
  fibrils with lifetimes of a few minutes. Shorter fibrils tend to turn
  faster than longer ones, which we interpret as due to vortex flows in
  the underlying granulation that twist magnetic fields.

Title: Propagating Waves in the Chromospheric Network
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2007ASPC..368..133G
Altcode:
  Wave modulation of ultraviolet emissions originated in and above quiet
  chromospheric network is studied. In particular, cross-correlation,
  wavelet analysis and phase difference analysis of the intensities
  as well as the Doppler shifts of emission lines of He I 584.33 Å
  (chromosphere), O V 629.73 Å (transition region) and Mg IX 368.07 Å
  (corona) are employed to study waves at different heights and their
  direction of propagation. The results are interpreted as evidence of
  compressive waves that propagate downward from the transition region
  to the chromosphere in the observed chromospheric network. Different
  scenarios regarding the origin and source localization of these waves
  are discussed.

Title: The height dependence of temperature velocity correlation in
    the solar photosphere
Authors: Koza, J.; Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 2007msfa.conf..139K
Altcode: 2007arXiv0704.0603K
  We derive correlation coefficients between temperature and line-of-sight
  velocity as a function of optical depth throughout the solar photosphere
  for the non-magnetic photosphere and a small area of enhanced magnetic
  activity. The maximum anticorrelation of about -0.6 between temperature
  and line-of-sight velocity in the non-magnetic photosphere occurs at
  log [tau] 5 = -0.4. The magnetic field is another decorrelating factor
  along with 5-min oscillations and seeing.

Title: Spectral Characteristics of the Photosphere near a Flare
Authors: Kučera, A.; Wöhl, H.; Rybák, J.; Wu, S. T.; Wang, A. H.
Bibcode: 2007CEAB...31...21K
Altcode:
  We present the temporal evolution of dynamical characteristics of the
  solar photosphere in an active region near a flare. Namely, spatial
  and temporal variations of Doppler velocities at different heights in
  the photosphere mapped by eight photospheric lines are presented for
  a time span of 45 minutes. The dynamics of the photosphere before and
  during a flare which occurred nearby is discussed. <P />We found that
  downward plasma motions are well pronounced up to 300 km height in the
  photosphere but did not reach deeper layers. The downward velocities of
  the plasma motion caused by the flare are about 1.2 km/s and they are
  channelled in a thin structure - flux-tube with diameter less than 0.8
  arcseconds. The velocities are better noticeable in the active parts
  of the target than in the quiet ones. The magnetic configuration of
  the active region is compared with the dynamics behaviour.

Title: The Height Dependence of Quiet-Sun Photospheric Temperature
    Fluctuations in Observations and Simulations
Authors: Koza, J.; Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 2006ASPC..354...43K
Altcode:
  We derive rms temperature fluctuations as a function of height
  throughout the solar photosphere for the non-magnetic photosphere and
  a small area of enhanced magnetic activity, through semi-empirical
  inversion based on response functions of a 15-minute time sequence
  of 118 arcsec-long slit spectrograms taken at disk center. While the
  observed low photosphere shows small temperature fluctuations (about
  ≈ 50 K), the sub-photospheric layers and the upper photosphere
  show larger fluctuations, with similar gradients as in 3-D radiation
  discretionary-hydrodynamics simulations. However, the observed rms
  temperature fluctuations are lower than in the simulations at all
  depths, which we attribute to smearing by atmospheric seeing.

Title: Long period variations of dm-radio and X-ray fluxes in three
    X-class flares
Authors: Mészárosová, H.; Karlický, M.; Rybák, J.; Fárník,
   F.; Jiřička, K.
Bibcode: 2006A&A...460..865M
Altcode:
  Aims.Long period (≥60 s) variations of the radio (0.8-4.5 GHz) and
  X-ray fluxes observed during the July 14, 2000, April 12, 2001, and
  April 15, 2001 flares by the Ondřejov radiospectrograph and Yohkoh
  spacecraft are studied by statistical methods.<BR /> Methods: .In
  the flares under study, characteristic periods are searched for by the
  Fourier and wavelet methods. To understand the origin of the 0.8-4.5 GHz
  drifting burst with long period variations, observed at the beginning of
  the April 15, 2001 flare, cross-correlations, time shifts, coherence,
  and phase differences in its time series are computed.<BR /> Results:
  .The global statistical study of these flares revealed characteristic
  periods in the interval of 60-513 s in the radio (0.8-4.5 GHz) and
  60-330 s in the X-ray Yohkoh fluxes. Cross-correlations between the
  radio fluxes at different frequencies helped us to determine the bursts
  generated by plasma or gyro-synchrotron mechanisms. In the April 12,
  2001 flare, soft X-ray fluxes of the sources located at the loop-top
  and footpoints of a flare loop vary with the period of 60-320 s, and
  they are highly correlated. But their relation to the radio (1.1 GHz -
  plasma emission and 4.0 GHz - gyro-synchrotron emission) is complex. At
  the beginning of the April 15, 2001 flare, in the 0.8-4.5 GHz range,
  a broadband drifting radio burst with the time variation of 61-320 s
  was observed at times of flare loop ejection. Its detailed statistical
  analysis shows that this burst consists of two parts, and, that first
  part is generated by the plasma emission mechanism and the second,
  probably, by the gyro-synchrotron one. The characteristic period of
  about 300 s found in three X-class flares in their dm-radio and X-ray
  emissions is discussed.<BR />

Title: A New Method for Comparing Numerical Simulations with
    Spectroscopic Observations of the Solar Photosphere
Authors: Rybák, J.; Kučera, A.; Wöhl, H.; Wedemeyer-Böhm, S.;
   Steiner, O.
Bibcode: 2006ASPC..354...77R
Altcode:
  A method for comparing high-resolution spectroscopic observations of
  the solar photosphere with numerical simulations of convection in the
  solar photosphere is presented. <P />It is based on the comparison of
  the granular continuum contrast obtained from both the observations and
  the synthetic spectra, when the latter are calculated from numerical
  simulations using a particular type of data degradation. This method
  can be used post facto when a minimum of auxiliary information on
  characteristics of the telescope/spectrograph and on seeing conditions
  is available. <P />Here, the method is applied to results of numerical
  simulations computed with the CO5BOLD code and high-resolution
  spectroscopic observations obtained with the VTT on Tenerife.

Title: Photospheric modeling through spectral line
    inversion. Temperature and radial velocity stratifications and
    fluctuations
Authors: Koza, J.; Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 2006A&A...458..941K
Altcode:
  Aims.We aim to determine average radial stratifications of various
  physical parameters throughout the solar photosphere at high angular
  resolution for non-magnetic and magnetic areas and to compare these
  with standard semiempirical 1D modeling and with 3D hydrodynamics (HD)
  and magnetohydrodynamics (MHD) simulations.<BR /> Methods: .We analyse
  a 15-min sequence of adaptive-optics spectrograms of very high angular
  resolution taken at solar disk centre. We split the data between a
  quiet area and a magnetic one and derive mean temperature and velocity
  stratifications and fluctuations for these separately by applying
  LTE inversion based on response functions.<BR /> Results: .The mean
  temperature stratifications in the non-magnetic region agree well with
  the classical 1D models and the 3D simulations at all heights. However,
  the observed rms temperature is much lower than in the simulations,
  the observed mean velocities indicate more upflows, and the observed
  velocity fluctuations are smaller except in upper layers. Some of
  the discrepancies are likely to result from remaining smearing by
  atmospheric seeing and instrumental limitations. The magnetic area
  shows conspicuous behaviour at large height. We also find evidence of
  fast low-photosphere downflows in the magnetic area and of enhanced
  temperature above a small pore.<BR />

Title: Periodicities in Irradiance and in other Solar Activity
    Indices During Cycle 23
Authors: Ataç, T.; Özgüç, A.; Rybak, J.
Bibcode: 2006SoPh..237..433A
Altcode: 2006SoPh..tmp...21A
  Magnetic fields give rise to distinctive features in different
  solar atmospheric regimes. To study this, time variations of the
  flare index, sunspot number and sunspot area, each index arising from
  different physical conditions, were compared with the solar composite
  irradiance throughout cycle 23. Rieger-type periodicities in these
  time series were calculated using Fourier and wavelet transforms
  (WTs). The peaks of the wavelet power of these periodicities appeared
  between the years 1999 and 2002. We found that the solar irradiance
  oscillations are less significant than those in the other indices
  during this cycle. The irradiance shows non-periodic fluctuations
  during this time interval. The peaks of the flare index, sunspot number
  and sunspot total area were seen around 2000.4, 1999.9 and 2001.0,
  respectively. These periodicities appeared intermittently and were
  not simultaneous in different solar activity indices during the three
  years of the maximum phase of solar cycle 23.

Title: Response of the Coronal N-S Asymmetry to its Manifestations
    in the Photosphere
Authors: Rybak, J.; Sykora, J.
Bibcode: 2006IAUJD...8E..22R
Altcode:
  The North-South (N-S) asymmetries of three solar activity indices
  are mutually compared over the period of more than five solar cycles
  (1945 - 2001). Our own catalogue of the hemispheric sunspot numbers,
  the database of the uniform coronal green line brightness and the
  magnetic field strength, as derived from the NSO/KP data (1975-2001),
  are treated within the discrete latitudinal zones (5° - 30° and 35°
  - 60°). The calculated paired correlations and regressions reveal
  much better expressed mutual relations between the N-S asymmetries
  than those are manifested if using the indices alone. A distinctly
  different behaviour of the N-S asymmetries found at different solar
  cycle phases separately for the low- and mid-latitude zones is picked
  out. The revealed differences could be considered when any dynamo
  theories of solar activity are developed.

Title: Study of a Small-Scale Eruptive Event Observed by SOHO/SUMER
Authors: Tomasz, F.; Régnier, S.; Schwarz, P.; Rybák, J.; Kucera,
   A.; Heinzel, P.; Curdt, W.; Wöhl
Bibcode: 2006ESASP.617E..79T
Altcode: 2006soho...17E..79T
  No abstract at ADS

Title: Multi-Wavelength Observations with High Resolution of a M5.4
    Flare from Ground and Space
Authors: Kucera, A.; Wöhl, H.; Rybák, J.; Gömöry, P.; Veronig, A.
Bibcode: 2006ESASP.617E..68K
Altcode: 2006soho...17E..68K
  No abstract at ADS

Title: The Dynamics and Structure of the Solar Atmosphere As Obtained
    from Combined SUMER/SOHO and TIP2/VTT Observations
Authors: Tomasz, F.; Régnier, S.; Schwartz, P.; Rybák, J.; Kucera,
   A.; Heinzel, P.; Curdt, W.; Wöhl
Bibcode: 2006ESASP.617E..78T
Altcode: 2006soho...17E..78T
  No abstract at ADS

Title: SOHO/CDS observations of waves above the network
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2006A&A...448.1169G
Altcode:
  We analyze temporal variations in the intensities and the Doppler shifts
  of He i 584.33 Å (chromosphere), O v 629.73 Å (transition region),
  and Mg ix 368.07 Å (corona) measured in and above chromospheric
  network near disk center with the Coronal Diagnostic Spectrometer
  (CDS) onboard the Solar and Heliospheric Observatory (SOHO). There is
  significant correlation between the He i and O v modulations, with O v
  intensity leading He i intensity by 27.3 s ± 4.6 s but no significant
  time shift in the Doppler shift. Cross-correlation between the O v
  and Mg ix intensities reveals multiple maxima without correlation
  between their Doppler shifts. Wavelet power analysis gives evidence
  of intermittent chromospheric and transition-region oscillations with
  periodicities in the 250-450 s range and of coronal oscillations in
  the 110-300 s range. Wavelet phase difference analysis shows that
  the determined time shift between variations of the He i and O v
  intensities is dominated by waves with about 300 s periodicity. We
  interpret these results as giving evidence of compressive waves that
  propagate downward from the transition region to the chromosphere in
  the particular chromospheric network. We discuss different scenarios
  regarding origin and source localization of waves, and we speculate
  on their role in coronal heating above chromospheric network.

Title: Hemispheric sunspot numbers {R<SUB>n</SUB>} and {R<SUB>s</SUB>}
from 1945-2004: catalogue and N-S asymmetry analysis for solar
    cycles 18-23
Authors: Temmer, M.; Rybák, J.; Bendík, P.; Veronig, A.; Vogler,
   F.; Otruba, W.; Pötzi, W.; Hanslmeier, A.
Bibcode: 2006A&A...447..735T
Altcode:
  From sunspot drawings provided by the Kanzelhöhe Solar Observatory,
  Austria, and the Skalnaté Pleso Observatory, Slovak Republic, we
  extracted a data catalogue of hemispheric Sunspot Numbers covering
  the time span 1945-2004. The validated catalogue includes daily,
  monthly-mean, and smoothed-monthly relative sunspot numbers
  for the northern and southern hemispheres separately and is
  available for scientific use. These data we then investigated with
  respect to north-south asymmetries for almost 6 entire solar cycles
  (Nos. 18-23). For all the cycles studied, we found that the asymmetry
  based on the absolute asymmetry index is enhanced near the cycle
  maximum, which contradicts to previous results that are based on the
  normalized asymmetry index. Moreover, the weak magnetic interdependence
  between the two solar hemispheres is confirmed by their self-contained
  evolution during a cycle. For the time span 1945-2004, we found that
  the cycle maxima and also the declining and increasing phases are
  clearly shifted, whereas the minima seem to be in phase for both
  hemispheres. The asymmetric behavior reveals no obvious connection
  to either the sunspot cycle period of ~11- or the magnetic cycle of
  ~22-years. The most striking excess of activity is observed for the
  northern hemisphere in cycles 19 and 20.

Title: Hemispheric Sunspot Numbers 1945--2004: data merging from
    two observatories
Authors: Temmer, M.; Rybák, J.; Bendík, P.; Veronig, A.; Vogler,
   F.; Pötzi, W.; Otruba, W.; Hanslmeier, A.
Bibcode: 2006CEAB...30...65T
Altcode:
  For the time span 1945--2004 from daily sunspot drawings northern
  and southern relative sunspot numbers are extracted using drawings
  provided by Kanzelhöhe Solar Observatory, Austria, and Skalnaté Pleso
  Observatory, Slovak Republic. The derived data will be used to improve
  and extend an already existing catalogue of hemispheric sunspot numbers
  (Temmer et al., 2002). Since northern and southern solar hemispheres
  do not evolve in phase during the cycle, hemispheric data are very
  important for activity studies. In the present paper the compilation
  of the data for the period 1945--2004 is described. Furthermore as a
  quality check of the derived hemispheric data a regression analysis and
  the comparison to the international hemispheric sunspot numbers from
  the Sunspot Index Data Center for the time span 1992--2004 is presented.

Title: Periodical patterns in major flare occurrence and their
    relation to magnetically complex active regions
Authors: Temmer, M.; Veronig, A.; Rybák, J.; Brajša, R.; Hanslmeier,
   A.
Bibcode: 2006AdSpR..38..886T
Altcode:
  A periodical occurrence rate of major solar flares (observed in hard
  X-rays) of ∼24 days (synodic) was first reported by Bai (1987)
  [Bai, T. Distribution of flares on the sun superactive regions and
  active zones of 1980 1985. ApJ 314, 795 807, 1987] for the years 1980
  1985. Here, we report a significant relation between the appearance of
  the 24-day period in major Hα flares and magnetically complex sunspot
  groups (i.e., including a γ and/or δ configuration). From synoptic
  maps of magnetograms (NSO/KP) patterns in the magnetic flux evolution
  are traced which might be the cause of the 24-day period observed in
  flare activity.

Title: Acoustic Flux and Turbulence in the Solar Photosphere
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 2006CEAB...30...11H
Altcode:
  Using slit scans of solar photospheric spectral lines originating in
  the middle photosphere a 2-D field on the Sun was obtained and the
  occurrence of acoustic flux is investigated. As proxies for acoustic
  flux generation enhanced turbulence (measured by fwhm variations) as
  well as large continuum intensity values are used. The results show
  that acoustic flux is not limited to the intergranular space and is
  also produced by horizontal motions that may become supersonic leading
  to turbulence. These motions lead to brightenings as it was predicted
  by theoretical models.

Title: Intermediate-Term Periodicities in Some Solar Activity Indices
    during Cycle 23
Authors: Ataç, T.; Özgüç, A.; Rybak, J.
Bibcode: 2005ESASP.600E.151A
Altcode: 2005dysu.confE.151A; 2005ESPM...11..151A
  No abstract at ADS

Title: Hemispheric Sunspot Numbers RN and RS from 1945-2004: Extended
    and Improved Catalogue
Authors: Temmer, M.; Rybák, J.; Veronig, A.; Bendík, P.; Vogler,
   F.; Pötzi, W.; Otruba, W.; Hanslmeier, A.
Bibcode: 2005ESASP.600E..52T
Altcode: 2005ESPM...11...52T; 2005dysu.confE..52T
  No abstract at ADS

Title: Influence of the 5-min oscillations on solar photospheric
    layers. I. Quiet region
Authors: Odert, P.; Hanslmeier, A.; Rybák, J.; Kučera, A.; Wöhl, H.
Bibcode: 2005A&A...444..257O
Altcode:
  Time series of 1D spectrograms are used to study the influence of the
  5-min oscillations on intensity and velocity fields of different layers
  of the quiet solar photosphere. We study the continuum intensity field
  along with intensity and corresponding velocity patterns of the mid and
  upper photosphere, obtained from two Fe lines. Oscillations seem to
  dominate the intensity and velocity fields of the higher atmospheric
  layers. Our results confirm the fast decay of the granular intensity
  structure with height. From correlations of temperature structures
  at three different photospheric levels we conclude that there are
  rapid changes of the structures in the lower photosphere, which are
  valid for the duration of the time series, while for the upper levels
  changes of the stuctures are fainter and show significant periodic
  character. The velocity pattern, on the other hand, shows a periodic
  propagation through the photosphere. The tests of the influence of
  seeing conditions on the data are considered.

Title: Statistical Analysis of Pulsations and Pulsations with Fibers
    in the Range 800-2000 MHZ
Authors: Mészárosová, H.; Rybák, J.; Zlobec, P.; Magdalenić,
   J.; Karlický, M.; Jiřička, K.
Bibcode: 2005ESASP.600E.133M
Altcode: 2005dysu.confE.133M; 2005ESPM...11..133M
  No abstract at ADS

Title: Analysis of Dynamics of Loops in AN Active Region Associated
    with a Small C-Class Flare
Authors: Gömöry, P.; Rybák, J.; Kucera, A.; Wöhl, H.
Bibcode: 2005ESASP.596E..56G
Altcode: 2005ccmf.confE..56G
  No abstract at ADS

Title: VizieR Online Data Catalog: Hemispheric Sunspot Numbers
    1945-2004 (Temmer+, 2006)
Authors: Temmer, M.; Rybak, J.; Bendik, P.; Veronig, A.; Vogler, F.;
   Otruba, W.; Poetzi, W.; Hanslmeier, A.
Bibcode: 2005yCat..34470735T
Altcode:
  From sunspot drawings provided by the Kanzelhoehe Solar Observatory,
  Austria, and the Skalnate Pleso Observatory, Slovak Republic,
  a data catalogue of hemispheric Sunspot Numbers covering the time
  span 1945-2004 is extracted. The validated catalogue includes daily,
  monthly-mean and smoothed-monthly relative sunspot numbers for the
  northern and southern hemispheres separately and is available for
  scientific use. Based on this data set an analysis concerning the
  North-South asymmetry is made within this paper. <P />(2 data files).

Title: Quasibiennial Oscillations of the North-South Asymmetry
Authors: Badalyan, O. G.; Obridko, V. N.; Rybák, J.; Sýkora, J.
Bibcode: 2005ARep...49..659B
Altcode:
  The north-south (N-S) asymmetry of the solar activity (A), which
  reflects differences in the behavior of the northern and southern
  hemispheres of the Sun, is studied using data on the brightness of the
  coronal green line, the total number and area of sunspots, and the net
  magnetic flux. The spatial and temporal distributions and correlations
  between the A values represented by these indices are considered. The
  characteristic time variations in A are similar for all the indices,
  on both long and short time scales. Quasibiennial oscillations (QBOs)
  can be traced in the asymmetries of all four indices. A detailed study
  of the QBOs is carried out based on spectral-variation and wavelet
  analyses. Long-term increases and decreases occur synchronously in
  the asymmetries of various indices and are much more pronounced in A
  than in the indices themselves. A negative correlation between the
  power of the QBOs and the asymmetry of A can be traced; it is most
  clearly manifest as a substantial diminishing of the QBOs during
  the mid-1960s, which coincided with an especially strong increase in
  A. Our analysis shows that the N-S asymmetry is probably a fundamental
  property that controls the coupling and degree of coincidence between
  the magnetic-field-generation mechanisms operating in the northern
  and southern hemispheres.

Title: What causes the 24-day period observed in solar flares?
Authors: Temmer, M.; Rybák, J.; Veronig, A.; Hanslmeier, A.
Bibcode: 2005A&A...433..707T
Altcode:
  Previous studies report a 24-day (synodic) period in the occurrence
  rate of solar flares for each of the solar cycles studied, Nos. 19-22
  (Bai 1987, ApJ, 314, 795; Temmer et al. 2004, Sol. Phys. 221,
  325). Here we study the 24-day period in the solar flare occurrence
  for solar cycles 21 and 22 by means of wavelet power spectra together
  with the solar flare locations in synoptic magnetic maps. We find
  that the 24-day peak revealed in the power spectra is just the
  result of a particular statistical clumping of data points, most
  probably caused by a characteristic longitudinal separation of about
  +40<SUP>circ</SUP> to +50<SUP>circ</SUP> of activity complexes in
  successive Carrington rotations. These complexes appear as parallel,
  diverging or converging branches in the synoptic magnetic maps and
  are particularly flare-productive.

Title: Analysis of Doppler Shifts of Spectral Lines Obtained by the
    CDS/SOHO Instrument
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2005ASSL..320..203G
Altcode: 2005smp..conf..203G
  No abstract at ADS

Title: On the Behaviour of a Blinker in Chromospheric and Transition
    Region Layers
Authors: Tomasz, F.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2005ASSL..320..207T
Altcode: 2005smp..conf..207T
  No abstract at ADS

Title: Variability and Dynamics of the Outer Atmospheric Layers in
    the Quiet Solar Network
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2005HvaOB..29...71G
Altcode:
  A detailed study of the temporal evolution of the chromospheric He
  I 584.33 Å and the transition region O V 629.73 Å emission line
  intensities of quiet supergranular network of the Sun near disk centre
  observed with Coronal Diagnostic Spectrometer (CDS) is presented. A
  wavelet analysis of the 1729 s (28.8 min) long temporal series was
  performed in order to derive the duration as well as periods of the
  chromospheric and the transition region oscillations. The He I line
  intensities show significant power for periods around 300 s (3.3 mHz),
  which is relevant only in the second half of the observing sequence
  (between 800 -- 1700 s). The temporal evolution corresponding to the
  O V line intensities shows strong power around the period of 400 s
  (2.5 mHz), which is significant during the whole observing sequence
  as well as the oscillation of lower power for periods of around 250 s
  (4.0 mHz), which is present only in the middle of the observing sequence
  (between 700 -- 1300 s).

Title: Overview of the flare index during the maximum phase of the
    solar cycle 23
Authors: Ataç, T.; Özgüç, A.; Rybák, J.
Bibcode: 2005AdSpR..35..400A
Altcode:
  A brief description and final results of the flare index of solar
  activity for the maximum phase of the cycle 23 are given. The patterns
  of similar activity indices that arise under different physical
  conditions during the cycle 23 were compared with the flare index. The
  intermediate-term periodicities in the daily flare index data for the
  full disc and for the northern and the southern hemispheres of the Sun
  were calculated before by the authors using the Fourier transform, and
  it was found that 64, 125 days periodicities are in operation during
  the maximum phase of the solar cycle 23. In this paper, we examined
  these periodicities in time domain by using the wavelet transform. The
  results of this transform show that during the maximum phase of the
  current solar cycle a very prominent multi-peaked structures exist in
  each solar hemisphere and the occurrence of flare index power is highly
  intermittent in time. Moreover, it is found that the flare activity
  of the opposite hemispheres were not well time-synchronized during
  the maximum phase. The flare activity of the southern hemisphere was
  observed to be more dominant in determining the characteristics of
  the flare activity in the solar cycle 23.

Title: Intermittence of the short-term periodicities of the flare
    index
Authors: Rybák, J.; Özgüç, A.; Ataç, T.; Sözen, E.
Bibcode: 2005AdSpR..35..406R
Altcode:
  Intermittence of the short-term periodicities (25-35 days) of the
  flare index are investigated using the wavelet transform method for
  the full-disc and for the northern and the southern hemispheres of
  the Sun separately over the epoch since 1966 until 2002. The wavelet
  transform results show that occurence of periodicities of flare index
  power is highly intermittent in time. The period-averaged wavelet
  power of the flare index presents this fact very clearly displaying
  independence of flaring activity on the solar hemispheres in several
  time intervals over almost four solar cycles under study. Moreover
  correlations of the period-averaged wavelet power of the flare index
  for the separate hemispheres and for the full-disc reveal significantly
  stronger relation between the full-disc and the northern hemisphere than
  between the full-disc and the southern hemisphere while no significant
  correlations was found between the hemispheres one another.

Title: High Resolution Observations of a M5.4 Flare
Authors: Kučera, A.; Wöhl, H.; Rybák, J.; Gömöry, P.; Tomasz, F.
Bibcode: 2005HvaOB..29..177K
Altcode:
  Hα observations of a M5.4 flare taken in the active region NOAA 10646
  with the Vacuum Tower Telescope at Observatório del Teide, Tenerife,
  on July 13, 2004 are presented. The temporal evolution of the area
  of the flare and its morphological changes are investigated and
  discussed. Simultaneous observations of the flare in EUV lines taken
  with CDS/SOHO instrument are shown and additional data from GOES-10
  instrument are compared.

Title: Coronal manifestations of solar variability
Authors: Sýkora, J.; Rybák, J.
Bibcode: 2005AdSpR..35..393S
Altcode:
  This contribution is mostly about phenomenology of what we see
  in space-time evolution of coronal green line brightness (CGLB),
  including its cyclic variations. Our own database (1943-2001) of the
  coronal Fe XIV 530.3 nm emission line intensities is used to display
  different aspects of the large-scale CGLB regularities and cyclic
  behaviour. Hemispheric asymmetry and relation of the longitudinal CGLB
  distribution to the rotational characteristics of the solar corona
  are particularly underlined.

Title: Influence of Transition Region Blinker on the Surrounding
    Chromospheric and Coronal Plasma
Authors: Tomasz, F.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2005HvaOB..29..197T
Altcode:
  Results of spectral analysis of a blinker observed in the transition
  region O VI 1037.63 Å line and in the chromospheric Ly β 1025.72
  Å line which were acquired using the SUMER spectrometer are
  presented. Chromospheric and coronal plasma in the vicinity of the
  blinker are investigated using also TRACE Ly α, UV continuum and Fe IX
  channels. It was found that initial release of energy was localized in
  the transition region and plasma has been spreading from transition
  region as a bi-directional jet. Energy reached chromosphere ∼60
  seconds after primary emission in the o6 line. There were detected
  enhanced emissions for about 25-38% in the chromospheric Lyα and UV
  continuum. Spatial extent of the blinker response is 6'' along the slit
  in the Lyα filtergram what is ∼3'' less than extent of the blinker
  in the o6 line. Maximum extent of the blinker response is 7.5'' in
  Lyα filtergram. Although, both Lyα and UV continuum reflect physical
  conditions in chromosphere, their patterns are completely different:
  pattern of the blinker response is compact in the Lyα and UV continuum
  shows non-compact structure below the transition region blinker. Coronal
  plasma was not influenced by the blinker although plasma moving toward
  observer was detected in the final phase of evolution of the blinker.

Title: Observational Evidences for Heating of the Solar Corona
    by Nanoflares in the Network Derived from the Transition Region
    Spectral Lines
Authors: Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2004ESASP.575..529R
Altcode: 2004soho...15..529R
  No abstract at ADS

Title: Dynamics of the Quiet Upper Solar Atmosphere in the Network
Authors: Gömöry, P.; Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2004ESASP.575..400G
Altcode: 2004soho...15..400G
  No abstract at ADS

Title: Evaluation of the short-term periodicities in the flare index
    between the years 1966 2002
Authors: Özgüç, Atila; Ataç, Tamer; Rybák, Ján
Bibcode: 2004SoPh..223..287O
Altcode:
  The short-term periodicities of the flare index are investigated in
  detail using Fourier and wavelet transforms for the full disc and for
  the northern and the southern hemispheres of the Sun separately over the
  epoch of almost 4 cycles (1966-2002). The most pronounced power peaks
  were found by the Fourier transform to be present at 25.6, 27.0, 30.2,
  and 33.8 days. The wavelet transform results show that the occurrence
  of periodicities of flare index power is highly intermittent in time. A
  comparison of the results of the Fourier transform and the time-period
  wavelet transform of the flare index time series has clarified the
  importance of different periodicities, whether they are or are not
  the harmonics of the basic ones, as well as the temporal location of
  their occurrence. We found that the modulation of the flare index due
  to the 27-day solar rotation is more pronounced during the declining
  portion of solar cycle than during the rising portion.

Title: Two-dimensional spectroscopic time series of solar granulation
Authors: Hanslmeier, A.; Kucera, A.; Rybák, J.; Wöhl, H.
Bibcode: 2004SoPh..223...13H
Altcode:
  In this paper we investigate the dynamics of the solar granulation
  by analyzing time series of 2D spatially highly resolved
  spectrograms. These were obtained by spatial scans covering a field
  of 12 8″ × 20″. The advantage of this method is a high spectral
  resolution, however, the data are not taken simultaneously and to
  cover the field described above 50 exposures taken sequentially in
  time are necessary. Therefore, to obtain one map about 2 minutes are
  required. Plots of the evolution of different line parameters are
  given as well as the decay of correlation functions. The correlations
  between the first map of line parameters and successive maps (which are
  separated by about 2 minutes) were investigated showing a rapid decay
  down to a correlation coefficient of 0.4 within 4 minutes, the velocity
  pattern in the field observed varies on smaller time scales. The
  temporal variation of correlation between the line parameters for the
  different lines shows a periodic signal related to 5-min oscillations
  which could not be totally filtered. The evolution of the correlation
  functions between line parameters is analyzed which gives an error
  estimate of all correlation values found in the literature. For
  the first time it is explicitly shown how evolution in a selected
  photospheric field influences the evolution of granular/intergranular
  structures.

Title: Indications of shock waves in the solar photosphere
Authors: Rybák, J.; Wöhl, H.; Kučera, A.; Hanslmeier, A.;
   Steiner, O.
Bibcode: 2004A&A...420.1141R
Altcode:
  High resolution observations of solar granulation near the solar limb
  are used in a search for hydrodynamic shocks caused by an abrupt
  braking of the fast (probably supersonic) horizontal flow of the
  granular plasma towards the intergranular lane. Shock signatures in
  the spectral line of Fe II 6456.38 Åof one particular observed shock
  event are investigated in detail. Evolution, amplitude, and spatial
  relation of the spectral line characteristics of the shock event are in
  agreement with predictions from numerical simulations for such shock
  phenomena in the solar photosphere. The dimensions and amplitudes of
  the observed shock signatures are comparable to predicted values when
  seeing and instrumental effects as well as a possible obliqueness of
  the shock front with respect to the observer's line-of-sight are taken
  into account. The temporal evolution of such an event is observed for
  the first time. The stable and declining phase of the event were studied
  for a time period of almost 2 min. A particular relationship was found
  between the shock event and a nearby G-band bright point located 2''
  from the shock event. It is suggestive that the observed shock is a
  causal consequence of the magnetic flux concentration, traced by the
  G-band bright point. Such a type of shock can appear outside the flux
  concentrations as a consequence of a rapid flux-tube motion.

Title: On the 24-day period observed in solar flare occurrence
Authors: Temmer, M.; Veronig, A.; Rybák, J.; Brajša, R.; Hanslmeier,
   A.
Bibcode: 2004SoPh..221..325T
Altcode:
  Time series of daily numbers of solar Hα flares from 1955 to
  1997 are studied by means of wavelet power spectra with regard to
  predominant periods in the range of ∼ 24 days (synodic). A 24-day
  period was first reported by Bai (1987) for the occurrence rate of
  hard X-ray flares during 1980-1985. Considering the northern and
  southern hemisphere separately, we find that the 24-day period is not
  an isolated phenomenon but occurs in each of the four solar cycles
  investigated (No. 19-22). The 24-day period can be established also
  in the occurrence rate of subflares but occurs more prominently in
  major flares (importance classes ≥ 1). A comparative analysis of
  magnetically classified active regions subdivided into magnetically
  complex (i.e., including a γ and/or δ configuration) and non-complex
  (α, β) reveals a significant relation between the appearance of
  the 24-day period in Hα flares and magnetically complex sunspot
  groups, whereas it cannot be established for non-complex groups. It is
  suggested that the 24-day period in solar flare occurrence is related
  to a periodic emergence of new magnetic flux rather than to the surface
  rotation of sunspots.

Title: On Relations among the Calibrated Parameters of the Transition
    Region Spectral Line
Authors: Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2004ESASP.547..311R
Altcode: 2004soho...13..311R
  SUMER/SOHO measurements of the O VI 1031.93 Å emission line (280000
  K) in the network and internetwork of the transition region of the
  quiet solar atmosphere are used for a statistical analysis of the
  calibrated spectral parameters: the central line intensity (energetic
  units), the line width (m Å) and the Doppler shift (km/s). A detailed
  procedure is performed in order to determine the absolute wavelength
  calibration of the spectra and Doppler shifts using simultaneously
  observed chromospheric O I 1027.44 Å and 1028.15 Å emission lines
  (10 000K). The spectral parameters of the O VI line are derived for
  both single and double Gaussian fitting of the line according to the
  latest findings on the multi-component nature of the transition region
  line profiles. Reliability of the absolute wavelength calibration and
  effects of two classes of the transition region transient events -
  explosive events and blinkers - are discussed in relation to the
  overall dependencies of the spectral parameters.

Title: Evidence of the fundamental periodicity in the flare index
    between the years 1966-2002
Authors: Özgüç, A.; Ataç, T.; Rybák, J.
Bibcode: 2004IAUS..223..557O
Altcode: 2005IAUS..223..557O
  No abstract at ADS

Title: Merging two data sets of hemispheric Sunspot Numbers
Authors: Rybák, J.; Bendík, P.; Temmer, M.; Veronig, A.; Hanslmeier,
   A.
Bibcode: 2004HvaOB..28...63R
Altcode:
  First results on merging two data sets of hemispheric sunspot numbers
  -- from the Kanzelhöhe Solar Observatory and the Skalnaté Pleso
  Observatory -- for the time span 1977 -- 1978 are presented. A total
  coverage of 86% was reached for the merged data set. In order to have
  a homogeneous time series, the daily sunspot numbers for the full disk
  from both observing stations were normalized to the international
  relative sunspot number of the day. The derived hemispheric sunspot
  numbers from Kanzelhöhe and Skalnaté Pleso Observatory %compared
  for 290 common observing show very high correlations (r ≳ 0.95), and
  the estimated data noise yields significant differences only for small
  values of sunspot numbers. These outcomes demonstrate the high potential
  of the applied merging procedure, and are the basis for an ongoing
  project to derive hemispheric sunspot numbers back to the year 1945
  using sunspot drawings from Kanzelhöhe and Skalnaté Pleso Observatory.

Title: On Mutual Relation Among the Outer Atmospheric Layers in
Network: SOHO/CDS Study
Authors: Gömöry, P.; Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2004ESASP.547..303G
Altcode: 2004soho...13..303G
  SOHO/CDS measurements of emission in the network of the quiet solar
  atmosphere near disk center were used to derive mutual relations
  of emission and dynamics in different temperature regimes in/above
  supergranular network. Cross-correlation functions of the line
  intensities and the Doppler shifts of the chromospheric line He I 584.3
  Å, the transition region line O V 629.7 Å and the coronal line Mg
  IX 396.1 Å were calculated in order to study relative variability
  of different atmospheric layers. Relatively high correlations were
  found between the intensities and the Doppler shifts of the He I and
  O V lines with two peaks of the intensity correlation function. The
  maximum value of the correlation of intensities (CC = 0.86) was reached
  for the zero time lag and the second maximum (CC = 0.78) was obtained
  for the time lag -190s (O V precedes He I). Only one sharp peak (CC =
  0.55) was detected in the Doppler shift correlation function of these
  lines for the zero time lag. For the correlation of O V and Mg IX
  intensities one peak (CC = 0.57) of the correlation function was also
  discovered for the time lag +150s (Mg IX falls behind O V). In contrast,
  no correlation was obtained for the Doppler shifts of the O V and Mg
  IX lines. Summarizing we can assume clear relation in energy transfer
  and/or mass motion between chromosphere and transition region but no
  relation was found between corona and the lower parts of the solar
  atmosphere above the particular network under study.

Title: Importance of magnetically complex active regions on solar
    flare occurrence
Authors: Temmer, M.; Veronig, A.; Rybák, J.; Brajša, R.; Hanslmeier,
   A.
Bibcode: 2004HvaOB..28...95T
Altcode:
  Daily numbers of solar Hα flares from 1955 to 1997 and daily numbers
  of magnetically classified active regions for the time span 1964--1997
  are studied applying wavelet power spectra. The occurrence of dominant
  periods in the range of ∼24 days (synodic) is investigated considering
  the northern and southern hemisphere separately. From the flare events
  it is revealed that the 24-day period occurs in each of the four solar
  cycles investigated (no. 19--22). The 24-day period can be established
  also in the occurrence rate of subflares but occurs more prominently
  in major flares (importance classes ≥1). Magnetically complex active
  regions, i.e. including a γ and/or δ configuration, show the 24-day
  period closely related to those found for major Hα flares, whereas
  it cannot be established for non-complex α, β groups.

Title: Velocity field in the intergranular atmosphere
Authors: Kučera, A.; Koza, J.; Bellot Rubio, L. R.; Hanslmeier, A.;
   Rybák, J.; Wöhl, H.
Bibcode: 2004HvaOB..28...19K
Altcode:
  The line-of-sight velocity ľand macroturbulent velocity are studied
  in the centre of the intergranular space in the solar photosphere. An
  inversion method is applied to a 4-min time sequence of Stokes
  I spectra of the 5, 6 and 7 lines observed with high spatial and
  temporal resolutions at solar disk centre. The results are presented
  in the form of the functional dependence of ľ(logτ<SUB>5</SUB>,t)
  and (t) on the continuum optical depth τ<SUB>5</SUB> at 500 nm and
  time t. A ľof several hundreds of meters per second was found in the
  upper photosphere (logτ<SUB>5</SUB>≤-1.5), where the plasma flows
  away from the observer. On the contrary, upflows directed toward the
  observer were found in deeper layers (logτ<SUB>5</SUB>&gt;-1.5). The
  typical value of in the centre of the intergranular space is found to be
  ∼1.7 kms, which is about 0.5 kms greater than in the adjacent granule.

Title: SUMER/SOHO and TRACE Study of the Transition Region Blinker
Authors: Tomasz, F.; Rybák, J.; Kucera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2004ESASP.547..307T
Altcode: 2004soho...13..307T
  The most prominent transient event is presented from an extensive
  search for the transition region internetwork activity in the quiet
  solar atmosphere performed by SUMER/SOHO spectrometer and TRACE. SUMER
  spectra of Ly line (1025.4 Å), two C II lines (1036.3 Å, 1037.0 Å)
  and O VI line (1037.61 Å) were used for determination of the spatial
  and temporal evolution of the transient event in the transition
  region. TRACE images taken in the 1216 Å passband, UV continuum
  (1700 Å) and Fe IX line (171 Å) were utilized in order to gain
  information about large-scale coronal structures and small-scale
  chromospheric variability in the vicinity of the transient event. The
  main physical and geometrical parameters of the event were derived
  for the transition region O VI line: the spatial extent of 11 000 km,
  duration for 9 minutes, intensity enhancement factor of 7 and the
  Doppler velocities of both signs up to 15 km/s. According to these
  values the event was identified as a transition region blinker. High
  deviations of the acquired O VI line profiles from single-Gaussian and
  some multi-Gaussian profiles reveal dynamics of the event - occurrence
  of the bidirectional jet which is not typical for blinkers. Besides
  rapid changes in intensity and in velocity, a rapid increase by a
  factor of 4.2 was found in the Gaussian width of O VI line as compared
  to the internetwork. Surrounding chromospheric and coronal structures
  around the event are discussed on base of the simultaneously taken
  TRACE images.

Title: One-dimensional spectroscopy of the solar photosphere
Authors: Odert, P.; Hanslmeier, A.; Rybák, J.; Kučera, A.; Wöhl, H.
Bibcode: 2004HvaOB..28...37O
Altcode:
  Data from a time series of spectrograms were used to study
  correlative relationships between intensity and velocity in the solar
  photosphere. The variations along the slit of the line parameters from
  two Fe lines lying in the visible range of the spectrum were used. The
  formation height difference of these lines is over 300 km. The temporal
  variations of the correlation coefficients were studied, they showed
  a strong influence of the 5 min-oscillations.

Title: Proper motions of sunspots - new data and further results
Authors: Wöhl, H.; Brajša, R.; Kučera, A.; Ruždjak, V.; Rybák, J.
Bibcode: 2004HvaOB..28...47W
Altcode:
  The attempts to investigate patterns of motions of main spot components
  and small pores in complex sunspot groups were continued. The data
  discussed stem mainly from observations at Hvar/HR and Tatranská
  Lomnica/SK. Two historic collections of photographic plates are
  included: The plate archives of the former Fraunhofer Institute and
  that of photographic plates taken at Skalnate Pleso/SK.

Title: Aspects of the solar variability in its coronal manifestations
Authors: Sykora, J.; Rybak, J.
Bibcode: 2004cosp...35.1243S
Altcode: 2004cosp.meet.1243S
  Temporal and spatial organizations of the solar corona brightness
  are well dependent from evolution, topology and strength of the
  solar magnetic field. On the other hand, all the activities,
  regularities, cyclicities and asymmetries observed in the solar
  corona, undoubtedly, modulate physical processes in the heliosphere,
  so contributing to creation of the space weather. Thus, all the
  findings about variabilities in the solar corona may contribute to
  a better understanding of both the lined topics. The large-scale and
  long-term distributions of the coronal Fe XIV 530.3 nm emission line
  brightness are obtained from analysis of the database covering the
  1943-2001 period. We demonstrate and discuss a fine structuralization
  of the butterfly diagram, existence of "active longitudes", presence of
  the double maxima in the solar cycles, N/S asymmetry and a particular
  relevance of the solar N and S middle-latitude zones for displaying
  the coronal variability and its responses in the heliosphere.

Title: Periodical patterns in major flare occurrence and their
    relation to magnetically complex active regions
Authors: Temmer, M.; Veronig, A.; Rybak, J.; Brajsa, R.; Hanslmeier, A.
Bibcode: 2004cosp...35.1395T
Altcode: 2004cosp.meet.1395T
  A periodical occurrence rate of solar major flares (observed in
  hard X-rays) of about 24 days (synodic) was first reported by Bai
  (1987) for the years 1980--1985. Its origin is still far from being
  understood. Applying wavelet analyses for daily numbers of Hα flare
  events covering almost four entire solar cycles (no. 19--22) reveals a
  24-day period in each of the cycles studied. This can be established
  primarily in the occurrence rate of major flares but is also seen
  in subflares. Since large flares occur preferentially in association
  with active regions of complex magnetic configuration a comparative
  study of magnetically classified active regions, subdivided into
  magnetically complex (i.e. including a γ and/or δ configuration)
  and non-complex (α, β) was performed. A significant relation
  between the appearance of the 24-day period in major Hα flares and
  magnetically complex sunspot groups is found, whereas it cannot be
  established for non-complex groups. From solar rotation studies based
  on tracing sunspots practically no siderial rotation velocities as high
  as 16 deg/day (which corresponds to a synodic period of ∼24 days)
  are reported. Thus the cause of the 24-day period is very likely not
  related to solar surface rotation. Alternatively it might be due to
  periodical patterns in magnetic flux emergence which is an important
  driver of flare eruptions. We test this hypothesis by investigating
  synoptic maps of magnetograms (National Solar Observatory/Kitt Peak)
  for selected time ranges in which the 24-day period is revealed for
  both flares and magnetically complex active regions.

Title: Evaluation of the short-term periodicities in the flare index
    between the years 1966-2001
Authors: Ozguc, A.; Atac, T.; Rybak, J.
Bibcode: 2004cosp...35..152O
Altcode: 2004cosp.meet..152O
  The short-term periodicities of the flare index are investigated in
  detail using Fourier and wavelet transforms for the total surface and
  for the northern and the southern hemispheres of the Sun separately
  over the epoch of almost 4 cycles (1966-2001). The most pronounced
  power peaks were found by the Fourier transform to be present at 25.3,
  27.0, 29.1, and 33.8 days. The wavelet transform results show that
  the occurrence of flare index power is highly intermittent in time. A
  comparison of the results of the Fourier transform and the time-period
  wavelet transform of the flare index time series has clarified the
  importance of different periodicities, whether they are or are not
  the harmonics of the basic ones, as well as the temporal location of
  their occurrence. Because we found that the modulation of the flare
  index due to the 27-day solar rotation is more pronounced during the
  declining portion of solar cycle than during the rising portion.

Title: Green corona versus photospheric magnetic flux: solar cycle
    dependence
Authors: Dorotovič, I.; Rybák, J.
Bibcode: 2003ESASP.535...87D
Altcode: 2003iscs.symp...87D
  The relation between the green corona and the photospheric magnetic flux
  has been analyzed over the period from 1995 to 2001. The homogeneous
  dataset of the green coronal line intensities and the Kitt Peak
  magnetic flux data were used for determining this relation. Focus
  was on the solar cycle dependence of the numerical relation between
  these two parameters has been investigated. Any overall fit with fixed
  parameters for the period of several years was shown to be unrealistic
  for describing this relation because the fit was found to be time
  dependent. The coefficients of the linear fit used in the paper show
  quite significant changes in their values with time. Moreover, the
  inverse relation of the absolute and the linear co-efficients of the
  fit was obtained during the ascending phase of the solar cycle between
  1998 and 2001. Therefore, in order to extrapolate magnetic flux data
  before 1975 using the existing longer datasets of the green coronal
  intensities, it is necessary to take into account the revealed solar
  cycle dependence of their relation and to estimate the quantitative
  parameters of the relation separately for the individual phases of
  the solar cycle.

Title: N-S asymmetry of solar activity and quasi-biennial oscillations
Authors: Badalyan, O. G.; Obridko, V. N.; Rybák, J.; Sýkora, J.
Bibcode: 2003ESASP.535...63B
Altcode: 2003iscs.symp...63B
  Space-time distribution and mutual correlation of the N-S
  asymmetry in various indices of solar activity are considered. It
  is shown that changes in the N-S asymmetry variation both at short
  and long time scales are consonant in all activity indices under
  consideration. Quasi-biennial variations of the asymmetry index and
  their space-time distribution are revealed and examined. The conclusion
  can be drawn that the N-S asymmetry is a specific independent and very
  promising tool for analysis of the solar activity variations.

Title: On rotational patterns of the solar magnetic field
Authors: Temmer, M.; Veronig, A.; Rybák, J.; Hanslmeier, A.
Bibcode: 2003ESASP.535..157T
Altcode: 2003iscs.symp..157T
  Solar magnetic field variations (NSO/Kitt Peak data) through solar cycle
  23 with respect to rotational modulations are analyzed. A comparative
  study to solar cycles 21 and 22 is performed. The results are compared
  to the rotational behavior of activity tracers like sunspots and solar
  Hα flares. Periodical occurrences of flares often match the 27-day
  solar rotation due to recurrent stable sunspot groups and complexes
  of activity which likely produce more flare events than short-living
  small sunspots. However, periods with strong deviations from the 27-day
  period are obtained for higher energetic flares. The solar magnetic
  field is found to vary on similar time scales, which suggests a close
  relation to the occurrence of strong flare events.

Title: Short-term periodicities in the flare index between the
    years 1966-2001
Authors: Özgüç, A.; Ataç, T.; Rybák, J.
Bibcode: 2003ESASP.535..141O
Altcode: 2003iscs.symp..141O
  A brief description and the results of the temporal variability
  of the flare index over the epoch of almost 4 cycles (1966-2001)
  are presented. Using Fourier and wavelet transforms the short-term
  periodicities in the daily flare index data for the total surface of
  the Sun are presented. A significant variability was found for all
  periods. The wavelet transform results show that the occurrence of
  flare index power is highly intermittent in time.

Title: On evolution of the photospheric magnetic fields on the
Sun: separation of active/dissipative/background fields by optimum
    thresholds
Authors: Mocák, M.; Rybák, J.
Bibcode: 2003ESASP.535..137M
Altcode: 2003iscs.symp..137M
  The distribution of the magnetic flux in the Sun's photosphere is
  studied using NSO/Kitt Peak Carrington rotaton maps of the magnetic
  flux in the period from 1975 to 2003. In principle it is possible
  to separate the magnetic fields using these magnetic data into three
  types: background fields, dissipative fields coming from the active
  regions and the active region fields themselves. This contribution
  discusses determination of the optimum thresholds for such separations
  of the magnetic fields. The threshold between background fields and
  dissipative fields is derived from the average minimal values of the
  magnetic flux measured in high latitudes where/when no active region
  flux and only minumum of the dissipative flux are detected. It's
  value is 2.8 Gauss. Contrary it is presented that there is no common
  value of the threshold between the dissipative fields and the active
  regions fields valid for the whole period under study. It is shown that
  value of this threshold is in fact unique not only for each Carrington
  rotation map but that it is specific even for each particular active
  region. Usually accepted value of 25 Gauss seems to be only the minimal
  limit of this threshold. Its maximal limit is exceeding value of 110
  Gauss. Nevertheless just separation between the background fields
  and the sum of the dissipative and the active region fields allows to
  discuss the temporal and latitudinal behaviour of these two types of
  the magnetic fields during evolution of the solar cycles.

Title: Mutual relations of the intermediate periodicities of the
    Wolf sunspot number
Authors: Rybák, J.; Karlovský, V.
Bibcode: 2003ESASP.535..145R
Altcode: 2003iscs.symp..145R
  First results of an analysis of the temporal variability of the solar
  activity represented by the relative Wolf sunspot number in the epoch
  1850-2002 are presented within range of the intermediate periods from
  0.3 up to 4 years. The daily data of the Wolf number has been utilized
  using the wavelet transform while different ways of estimation of the
  significance of periods were applied. The performed analysis was focused
  on a search for possible mutual relations between the appearance
  of the intermediate periods and their connection to the overall
  course of the cycle of solar activity. Results have revealed several
  significant periods but, in general, only of an intermittent character
  of appearance. Besides some other periods especially that of ~2-year,
  ~1.3-year, ~0.75-year and 4-year were found to be significant in several
  instances of time. Comparison of these results allow to conclude that
  the quasi-biennial period is not related to any particular phase of
  the solar cycle and that presence of the 4-year period is independent
  from the quasi-biennial period. Additionally the well-known 155-day
  period was confirmed with its particular intermittent appearance both
  in phase and out of phase of the 1.3-year period in difference time
  intervals. Possible influence of estimation of the background noise
  for determination of the significance of periods is discussed as well.

Title: On the Shape of Cosmic Ray Modulation during Evenand
    Odd-Numbered Solar Activity Cycles
Authors: Kudela, K.; Storini, Marisa; Massetti, Stefano; Rybak, Jan
Bibcode: 2003ICRC....7.4095S
Altcode: 2003ICRC....7.4095K; 2003ICRC...28.4095S
  Data from several neutron monitors are used to investigate the
  cosmic ray modulation for different rigidity intervals in the period
  1953-2002. From the shape of the cosmic ray modulation it turns out
  that the ∼1.3-yr periodicity, identified also by the use of the
  wavelet technique, results highly significant during the second stage
  of cosmic ray modulation in even/odd heliomagnetic semicycles.

Title: Temporal variability of the flare index (1966-2001)
Authors: Özgüç, Atila; Ataç, Tamer; Rybák, Ján
Bibcode: 2003SoPh..214..375O
Altcode:
  A brief description and study of the temporal variability of the flare
  index over the epoch of almost 4 cycles (1966-2001) are presented. Using
  Fourier and wavelet transforms the long- and the intermediate-term
  periodicities in the daily flare index data for the total surface and
  for the northern and the southern hemispheres of the Sun are given in
  detail. A significant variability was found for all periods including
  those of 150 days and 1.3 years. The wavelet transform results show
  that the occurrence of flare index power is highly intermittent in
  time. A comparison of the results of the Fourier transform and the
  time-period wavelet transform of the flare index time series has
  clarified the importance of different periodicities, whether they are
  or are not the harmonics of the basic ones, as well as the temporal
  location of their occurrence.

Title: Dynamics and turbulence of the chromospheric layers of a
    flaring atmosphere
Authors: Brčeková, K.; Kučera, A.; Hanslmeier, A.; Rybák, J.;
   Wöhl, H.
Bibcode: 2003AN....324..366B
Altcode:
  No abstract at ADS

Title: Transition region blinker - spatial and temporal behaviour
Authors: Tomasz, F.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2003HvaOB..27...75T
Altcode:
  From an extensive search for transition region internetwork activity
  in the quiet Sun atmosphere the most prominent transient event is
  presented. The basic physical and geometrical parameters of this event
  are derived from the O VI 1037.61 Å emission spectral line. The spatial
  extent of 11 000 km, duration for 9 minutes, intensity enhancements
  factor of 7 and large Doppler velocities of both signs were estimated
  for the event. According to these values this event was identified as
  a transition region blinker.

Title: Proper motions of sunspot groups
Authors: Wöhl, H.; Brajša, R.; Kučera, A.; Ruždjak, V.; Rybák, J.
Bibcode: 2003HvaOB..27....1W
Altcode:
  Attempts to investigate typical patterns of motions of main spot
  components and small pores in complex sunspot groups are described. The
  data used up to now stem from observations at Hvar/HR, Tatranská
  Lomnica/SK, Izaña/E, Debrecen/H and from the MDI instrument on
  SoHO. Preliminary results are presented.

Title: Evolution of temperature in granule and intergranular space
Authors: Koza, J.; Bellot Rubio, L. R.; Kučera, A.; Hanslmeier, A.;
   Rybák, J.; Wöhl, H.
Bibcode: 2003AN....324..349K
Altcode:
  The temporal evolution of temperature in a dissolving granule and
  in an adjacent intergranular space is presented. The semi-empirical
  evolutionary models have been calculated using an inversion method
  applied to 4-min time series of Stokes I spectral line profiles. The
  models are presented in the form of the functional dependence of
  temperature T(log tau_5 ,t) on optical depth tau_5 at 500 nm and time
  t. The observed disappearance of the granule is accompanied with overall
  cooling of the granular photosphere. Temperature changes greater than
  100 K have been found in deeper (log tau_5 &gt;=0) and upper layers
  (log tau_5 &lt;=-2) whereas the intermediate layers are thermally
  stable. The intergranular space, which is 2 arcsec off the granule,
  keeps the temperature structure of the layers from log tau_5 =0.5 to
  log tau_5 =-2 without global evolutionary changes except short-term
  and spatially confined heating. Finally, the significant temperature
  changes in the upper layers (log tau_5 &lt;=-2.5) observed during the
  time interval of 4 min are found to be typical for the granular and
  intergranular photosphere.

Title: Observational evidence for a shock event in the solar
    granulation
Authors: Kučera, A.; Rybák, J.; Hanslmeier, A.; Wöhl, H.
Bibcode: 2003HvaOB..27...25K
Altcode:
  High resolution spectra of Fe II 6456.39 Å line are used to investigate
  a shock in the solar granulation. The changes of the main spectral
  characteristics measured in the shock area are in a good agreement with
  the characteristics predicted with theory. The analysis of the shock,
  made in the past by several authors was extended in this work to the
  analysis of a temporal development of the shock event. The 2 minutes
  duration of a stable and declining phases of the event was studied. We
  conclude that the observed shock belonged to the particular type of
  shock generated as a consequence of the swaying motion of the magnetic
  flux tube concentrated in the intergranular lane. Such type of shock
  was proposed by numerical simulations made by Steiner et al. 1998.

Title: Rotational modulation of northern and southern activity tracers
Authors: Temmer, M.; Veronig, A.; Rybák, J.; Hanslmeier, A.
Bibcode: 2003HvaOB..27...59T
Altcode:
  We study solar activity phenomena, Hα flares and sunspots, with respect
  to their periodical occurrence related to the solar rotation. The
  analysis is carried out separately for the northern and the southern
  hemisphere. Furthermore, flare occurrences are studied with respect
  to different importance classes, and the results are compared to
  the predominant periods derived from Sunspot Numbers. Significant
  asymmetries are obtained between the northern and southern activity for
  both Sunspot Numbers and flare occurrences. Differences between Sunspot
  Numbers and flares result particularly when only higher energetic
  flares are considered. A 24-day period is found for large flare events
  in both hemispheres which is not detected in Sunspot Numbers.

Title: Transition region eruptive event observed with SOHO/CDS in
    the quiet Sun network
Authors: Gömöry, P.; Rybák, J.; Kučera, A.; Curdt, W.; Wöhl, H.
Bibcode: 2003HvaOB..27...67G
Altcode:
  CDS observations of the quiet Sun network in the chromospheric He I
  584.33 Å and transition region O V 629.73 Å emission lines over
  a time period of ∼ 29 min are presented. One eruptive event was
  detected in this time series of data. The parameters of the network
  eruptive event are derived and the type of this small-scale activity
  is identified. The lifetime of the event was ∼ 1 min and it was
  found only in the transition region emission line. This event had no
  chromospheric counterpart. All O V spectral profiles of the eruptive
  event were blueshifted and the maximal Doppler shift was -14.7 km
  s<SUP>-1</SUP>. During an initial phase of the eruptive event, the
  O V intensity enhancement factor was 2.3. These parameters indicate
  that the observed event could be a transition region explosive event
  but measured with the limited resolution of the CDS instrument.

Title: Line intensities of chromospheric and photospheric spectra
    of a flare
Authors: Brčeková, K.; Kučera, A.; Hanslmeier, A.; Rybák, J.;
   Wöhl, H.
Bibcode: 2002ESASP.506..557B
Altcode: 2002ESPM...10..557B; 2002svco.conf..557B
  In this work we present the intensities of spectral lines determined
  from the time series of high resolution spectra obtained during
  the relaxing phase of subflare. The spectra were taken in the core
  of chromospheric Ca II K line and in two photospheric Fe I 522.5 nm
  and Fe I 557.6 nm lines. It is shown, that the energy of the flaring
  chromosphere slightly affects the underlying photospheric layers by
  heating a small area right under the core of the subflare.

Title: Two-dimensional spectroscopic time series of solar granulation:
    evolution of individual granules
Authors: Hanslmeier, Arnold; Kučera, Ales; Rybák, Jan; Wöhl,
   Hubertus
Bibcode: 2002ESASP.506..633H
Altcode: 2002svco.conf..633H; 2002ESPM...10..633H
  In this paper we investigate the dynamics of the solar granulation by
  analyzing time series of 2-D spatially highly resolved spectrograms. The
  high quality of the data permitted us to follow the evolution of
  individual granular and intergranular areas. We used scans over the
  solar surface in order to obtain a 2-D information. This has the
  advantage of achieving high spectral and spatial resolution, however
  one scan lasted for about 2 min.

Title: Cycle dependence of hemispheric activity
Authors: Temmer, M.; Veronig, A.; Rybák, J.; Hanslmeier, A.
Bibcode: 2002ESASP.506..859T
Altcode: 2002ESPM...10..859T; 2002svco.conf..859T
  Data of daily hemispheric Sunspot Numbers are analyzed including the
  time span 1975-2001. The study of north-south asymmetries concerning
  solar activity and rotational behaviors is in particular relevant,
  as it is related to the solar dynamo and the generation of magnetic
  fields. As diagnostic tools we use wavelets and autocorrelation
  functions in combination with statistical significance tests that are
  applied separately to the northern and southern hemisphere. Pronounced
  differences between the northern and southern rotational periods
  are obtained. The northern hemisphere shows a rigid rotation of ~27
  days which can be followed up to ~15 periods in the autocorrelation
  function. The signal of the southern hemisphere is strongly attenuated
  after 3 recurrences showing variable periods in the range ~26-28.5
  days. The presence of these periods is not permanent during a cycle
  suggesting activity pulses in each hemisphere. For the northern
  hemisphere strong relations to the motions of deeper lying convective
  structures building up long-living 'active zones' are suggested.

Title: Line-of-sight velocity in a semiempirical model of a
    disappearing granule
Authors: Koza, J.; Bellot Rubio, L. R.; Kučera, A.; Hanslmeier, A.;
   Rybák, J.; Wöhl, H.
Bibcode: 2002ESASP.506..443K
Altcode: 2002svco.conf..443K; 2002ESPM...10..443K
  The behaviour of the line-of-sight velocity in the centre of a
  disappearing granule is analyzed using an inversion method applied
  to a time-series of spectra containing the Fe I 522.5 nm, 557.6
  nm and 557.7 nm lines. The temporal evolution of the line-of-sight
  velocity v<SUB>LOS</SUB> is presented in the form of the functional
  dependence of v<SUB>LOS</SUB>(logτ<SUB>5</SUB>, t) on the optical
  depth τ<SUB>5</SUB> at 500 nm and time t. An oscillatory behaviour
  is found in the velocity stratification with nearly constant phase
  through the photosphere. The amplitude of variations increases from
  logτ<SUB>5</SUB> = -0.3 to logτ<SUB>5</SUB> = -2.5 reaching a maximum
  of ~1.2 km s<SUP>-1</SUP>. A zero velocity layer is detected in every
  instantaneous model of the velocity stratification. The results suggest,
  that the zero velocity may occur in a considerable range of the optical
  depths from logτ<SUB>5</SUB> ~ -2 to logτ<SUB>5</SUB> ~ -3.5.

Title: Long-term periodicities in the flare index between the years
    1966 - 2001
Authors: Özgüç, A.; Ataç, T.; Rybák, J.
Bibcode: 2002ESASP.506..709O
Altcode: 2002svco.conf..709O; 2002ESPM...10..709O
  A brief description and the results of the temporal variability
  of the flare index over the epoch of almost 4 cycles (1966-2001)
  are presented. Using Fourier and wavelet transforms the long-term
  periodicities in the daily flare index data for the total surface
  and for the northern and the southern hemispheres of the Sun are
  presented. A significant variability was found for all periods. The
  wavelet transform results show that the occurrence of flare index
  power is highly intermittent in time.

Title: Precise reduction of solar spectra obtained with large
    CCD arrays
Authors: Wöhl, H.; Kučera, A.; Rybák, J.; Hanslmeier, A.
Bibcode: 2002A&A...394.1077W
Altcode:
  A precise procedure suitable for the reduction of solar spectra
  taken with large CCD arrays and the retrieval of correct spectral
  characteristics is presented. Various effects, which one should take
  into account, are considered and several improvements of the standard
  reduction are introduced. A special flat-field procedure is suggested
  for the reduction of spectra registered in different flat-field
  conditions than those when the flat-field matrix was taken. The original
  flat-field matrix is split into several components to eliminate the
  influence of the drift of the spectrograph and temporal changes of
  the flat-field conditions on the reduced spectrum. The importance
  of every flat-field matrix component is tested and discussed and the
  noise propagation through data reduction is analyzed. It is documented
  that the errors of the basic spectral line characteristics, continuum
  intensity, line centre intensity and full width at the half maxima
  of the line have variations between 0.5% and 15% and the errors of
  the line centre Doppler velocity and bisectors fluctuate by up to 200
  m s<SUP>-1</SUP>, if derived from imprecise reductions, compared to
  precise ones.

Title: Temporal evolution of physical parameters in granule
Authors: Koza, J.; Kucera, A.; Hanslmeier, A.; Rybák, J.; Wöhl, H.
Bibcode: 2002ESASP.505..457K
Altcode: 2002solm.conf..457K; 2002IAUCo.188..457K
  The temporal evolution of the physical parameters inside a granule
  is presented. This is a step towards a more realistic 1D modeling
  of the solar granulation, avoiding the temporal averaging used up
  to now. The granulation is treated as a dynamical phenomenon and our
  model has been calculated using an inversion method applied to time
  series of spectra. The granular evolutionary model is presented in
  the form of the functional dependence of temperature T(log τ, t) and
  line-of-sight velocity v<SUB>LOS</SUB>(log τ, t) on optical depth τ
  and time t. The observed disappearance of the granule is accompanied
  with significant temperature changes greater than ~300K in deeper layers
  (log τ<SUB>5</SUB> &gt; 0) and upper layers (log τ<SUB>5</SUB> &lt;
  -2.5). In contrary, the layers from log τ<SUB>5</SUB> ~= -0.5 to log
  τ<SUB>5</SUB> ~= -1.5 are more stable in the sense of temperature
  variations, which are less than ~150K. An oscillatory behavior is
  found in the line-of-sight velocity stratification from log τ5 ~= 0
  upwards with increasing amplitude reaching up to ~= 2 km s<SUP>-1</SUP>
  in upper layers.

Title: Dynamic coupling of the chromospheric and photospheric
    flaring plasma
Authors: Brceková, K.; Kucera, A.; Hanslmeier, A.; Rybák, J.;
   Wöhl, H.
Bibcode: 2002ESASP.505..357B
Altcode: 2002solm.conf..357B; 2002IAUCo.188..357B
  The relaxing phase of the subflare observed in the core of chromospheric
  Ca II K line and in two photospheric Fe I 522.5 nm and Fe I 557.6 nm
  lines was investigated. The temporal evolution of asymmetry in Ca II
  K line and the mean bisectors positions of the Fe I line profiles as
  well as their correlations are presented. It is documented that the
  chromospheric down-flow caused by the subflare strongly affects the
  upper layers of the photosphere. As a consequence of relaxation of
  the photospheric layers strong down-flows and up-flows were measured
  at the end of the subflare relaxing phase.

Title: High-resolution CCD spectra reduction: temporal changes of
    the flat-field compensation
Authors: Kučera, Aleš; Hanslmeier, Arnold; Rybák, Ján; Wohl,
   Hubertus
Bibcode: 2002NCimC..25..703K
Altcode:
  A new method suitable for long-time series of high-resolution CCD
  spectra reduction is presented. The method allows to compensate the
  temporal changes of the instrument conditions which leads to temporal
  changes of the flat-field matrix. Sometimes it is impossible to make
  the flat-field measurements during long simultaneous observations with
  satellites (SOHO, TRACE). The method splits the flat-field matrix into
  two components. The first one, connected with CCD camera is stable in
  time and is correct for all spectra. The second one varies and reflects
  temporal changes of the conditions in the spectrograph. Description
  of the method and its application to real high-resolution CCD spectra
  is presented and discussed.

Title: Flare index variability in the ascending branch of solar
    cycle 23
Authors: Özgüç, A.; Ataç, T.; Rybák, J.
Bibcode: 2002JGRA..107.1146O
Altcode:
  A brief description and the results of the determination of the flare
  index as a measure of solar activity on the ascending branch of cycle 23
  up to 31 December 2000 are presented. The patterns of similar activity
  indices that arise under different physical conditions during the rising
  activity phase are compared with the flare index. All studied solar
  indices rise more slowly in the current cycle than the last one, except
  the total solar irradiance. The intermediate-term periodicities in the
  daily flare index data were studied using the Fourier transform, and
  it was found that the 35-, 62-, 116-, 198-, and 276-day periodicities
  are in operation during the ascending branch of cycle 23. Contrary to
  the previous three cycles, 155-, 73-, or 51-day periodicities were not
  detected by the Fourier transform in this branch of the cycle. The
  wavelet transform results show that the occurrence of flare index
  power is highly intermittent in time, and the most pronounced power
  peaks were found to be present at 35 days (the temporal locations at
  1998.3, 1999.9, and 2000.5 years), 116 days (the temporal interval
  1999.7-2000.4 years) and 276 days period (interval roughly from 1999.5
  until the end of the flare index data). Comparison of the Fourier and
  wavelet transform results has clarified the importance of different
  periodicities, whether they are (62, 198 days) or are not (35, 116,
  276 days) the harmonics of the basic ones, as well as the temporal
  location of their occurrence.

Title: Transition region dynamics from SUMER/SOHO observations:
    shape of the emission spectral lines
Authors: Rybák, J.; Curdt, W.; Kučera, A.; Wöhl, H.
Bibcode: 2002ESASP.477..163R
Altcode: 2002scsw.conf..163R
  The quiet sun network/internetwork transition region line profiles
  of C II 1036.34 Å and O VI 1037.61 Å are outlined emphasizing
  the temporal/spatial behaviour of their deviations from the
  Gaussian shape. Systematic deviations of the line profiles from the
  single-Gaussian shape indicate that transition region emission lines
  consist of two Gaussian components over almost the whole quiet sun
  internetwork except their small innermost parts. This finding is in
  qualitative agreement with the transition region model of Peter (2001).

Title: The North-South asymmetry of solar activity
Authors: Badalyan, O. G.; Obridko, V. N.; Rybák, J.; Sýkora, J.
Bibcode: 2002ESASP.477..201B
Altcode: 2002scsw.conf..201B
  In the present paper the North-South (N-S) asymmetry of four solar
  activity indices is estimated and discussed. The coronal green line
  intensity measurements, the Wolf numbers and the sunspot area data
  - all of them were subjected to analysis over the 1943-1999 period,
  together with the NSO/KP data on the total magnetic field flux measured
  from 1975. The pair comparison of these four indices within different
  zones of solar latitude allowed to reveal a number of features in
  their mutual correlativness. As the coronal green line intensity as
  the sunspot area display a long-termed wave in their N-S asymmetry -
  about 40 years in duration. While during the first half of the interval
  studied the N-hemisphere dominates (with a clear maximum around 1964-66)
  then during the second half of the interval the activity measured over
  the S-hemisphere prevails. Quasi-biennial variations were identified
  both in the N-S asymmetry of the coronal green line brightness and
  that of the total magnetic flux. The performed study indicates a close
  relation between the global and local manifestations of solar activity,
  which are governed by the magnetic fields of different scales.

Title: Time Evolution of low-Frequency Periodicities in Cosmic
    ray Intensity
Authors: Kudela, K.; Rybák, J.; Antalová, A.; Storini, M.
Bibcode: 2002SoPh..205..165K
Altcode:
  The long-time series of daily means of cosmic-ray intensity observed by
  four neutron monitors at different cutoff rigidities (Calgary, Climax,
  Lomnický Štít and Huancayo/Haleakala) were analyzed by means of
  the wavelet transform method in the period range ∼ 60 to ∼ 1000
  days. The contributions of the time evolution of three quasi-periodic
  cosmic-ray signals (∼ 150 d, ∼ 1.3 yr and ∼ 1.7 yr) to the
  global one are obtained. While the ∼ 1.7-yr quasi-periodicity, the
  most remarkable one in the studied interval, strongly contributes to
  the cosmic ray intensity profile of solar cycle 21 (particularly in
  1982), the ∼ 1.3-yr one, which is better correlated with the same
  periodicity of the interplanetary magnetic field strength, is present
  as a characteristic feature for the decreasing phases of the cycles
  20 and 22. Transitions between these quasi-periodicities are seen in
  the wavelet power spectra plots. Obtained results support the claimed
  difference in the solar activity evolution during odd and even solar
  activity cycles.

Title: Temporal Variability of the Coronal Green-Line Index
    (1947-1998)
Authors: Rybák, J.; Dorotovič, I.
Bibcode: 2002SoPh..205..177R
Altcode:
  Temporal variability of the coronal index - the `Sun as a star' coronal
  green-line irradiance - is presented using wavelet transform over
  the epoch of almost 5 solar cycles. A significant index variability
  was found for all periods, particularly for the periods of 150 days
  and 1 year as well as 28 days. Connection of the variability with the
  phase of solar magnetic activity is outlined. The enhanced power of
  the 150-day period is dominant before and after the magnetic activity
  maxima in four out of the five cycles analyzed. To the contrary, no
  enhanced power was found just during the maxima of all cycles for this
  period. No clear periodic power behavior was found for the periods at
  about one year. Substantial rotation period variations of the coronal
  index up to 5 days take place over relatively short time intervals. A
  comparison of the results of the Fourier transform and the time-period
  wavelet transform of the coronal index time series shows that only the
  application of the wavelet analysis enables one to find the relation
  between the coronal index variability and the course of the magnetic
  activity of the Sun.

Title: Comparing wavelet and traditional studies in the Gnevyshev
    Gap context
Authors: Storini, M.; Laurenza, M.; Rybak, J.; Antalova, A.; Kudela, K.
Bibcode: 2002cosp...34E2174S
Altcode: 2002cosp.meetE2174S
  As it is now well established the Gnevyshev Gap is a significant
  phenomenon of the solar activity maxima (e.g. [1-3]) and Wavelet
  Transform Method allows to investigate non-stationary processes
  containing multi-scale features. Results from such kind of method
  applied to several parameters of the Solar-Terrestrial System are
  used together with the ones from traditional investigation methods to
  better understand controversial findings obtained during the maximum
  phase of the last four solar activity cycles. [1] F. Feminella and
  M. Storini (1997), Astron. Astrophys. 322, 311. [2] G.A. Bazilevskaya
  et al. (2000), Solar Phys. 197, 157. [3] M. Storini et al. (2002),
  Adv. Space Res., in press.

Title: Temporal variability of the flare index (1966-2001)
Authors: Ozguc, A.; Atac, T.; Rybak, J.
Bibcode: 2002cosp...34E.511O
Altcode: 2002cosp.meetE.511O
  A brief description and the results of the temporal variability of the
  flare index over the epoch of almost 4 cycles are presented. Using
  Fourier and wavelet transforms the long, the intermediate and the
  short-term periodicities in the daily flare index data for the total
  surface and for the northern and the southern hemisphere of the Sun were
  presented. A significant variability was found for all periods. The
  wavelet transform results show that the occurrence of flare index
  power is highly intermittent in time. A comparison of the results of
  the Fourier transform and the time-period wavelet transform of the
  flare index time series has clarified the importance of different
  periodicities, whether they are or are not the harmonics of the basic
  ones, as well as the temporal location of their occurrence.

Title: On the quasi-biennial modulation of galactic cosmic rays
Authors: Storini, M.; Rybak, J.; Antalova, A.; Kudela, K.
Bibcode: 2001ICRC....9.3768S
Altcode: 2001ICRC...27.3768S
  Results from the wavelet power spectrum (WPS) analysis of the cosmic
  ray intensity, registered by the Calgary neutron monitor from 1969 to
  1998 years, are used to discuss the characteristic behaviour of the
  quasi-biennial modulation of galactic cosmic rays during solar activity
  cycles n. 21 and n. 22. Results from the temporarily averaged global
  power spectra (GPS) are also shown.

Title: On the wavelet approach to cosmic ray variability
Authors: Kudela, K.; Storini, M.; Antalova, A.; Rybák, J.
Bibcode: 2001ICRC....9.3773K
Altcode: 2001ICRC...27.3773K
  A wavelet transform (time scale ~60 to ~1000 days) is applied on the
  long-term time series of daily means of cosmic ray intensity observed
  by neutron monitors at different cutoff rigidities. No persistent
  periodicities with the same amplitude are found for the whole period
  analyzed. The temporal evolution of quasiperiodic variations at
  ~150 days, ~1.3 years and ~1.7 years is examined. While the ~1.7-y
  quasiperiodicity (the most remarkable one in the studied interval) is
  strongly contributing to the cosmic ray intensity profile of solar cycle
  21 (particularly in 1982), the ~1.3-y one (which is better correlated
  with the same periodicity of the interplanetary magnetic field strength)
  is a characteristic feature for the decreasing phases of the cycles 20
  and 22. Transitions between them are seen from the wavelet power spectra
  plots. Obtained results give a support to the claimed difference in
  the solar activity evolution during odd and even solar activity cycles.

Title: The Solar and Cosmic-Ray Synodic Periodicity (1969 1998)
Authors: Antalová, A.; Kudela, K.; Rybák, J.
Bibcode: 2001SSRv...97..355A
Altcode:
  The synodic recurrence of the Mt. Wilson plage index (MPSI) and the
  Calgary cosmic ray (CR) intensity is investigated, using the wavelet
  power spectra in the range of 18 38 days, during the last three solar
  cycles. The unique temporal coincidence between the quasi synodic MPSI
  and the CR periods is detected in 1978 1982 (the 21st solar cycle). In
  the 22nd cycle there is a very strong MPSI synodic recurrence, from
  1989.5 to 1990.5, but it is absent in the CR data. In 1992.5 1993.5
  the MPSI and CR recurrence phenomenon is in good accordance with the
  solar wind speed and cosmic ray modulation as measured during the
  first Ulysses passage around the Sun. The Gnevyshev gap is present in
  the 27-day recurrence of CR, in agreement with Kudela et al. (1999).

Title: The Location of Solar Oscillations in the Photosphere
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 2001ASSL..259..267H
Altcode: 2001dysu.conf..267H
  Applying a correlation analysis to time series of granulation it has
  been shown that due to the influence of enhanced turbulent motions
  near the downflow regions in the intergranular lanes the turbulent
  motions predominate.

Title: Chromospheric Dynamics as can be Inferred from SUMER/SOHO
    Observations
Authors: Rybák, J.; Kučera, A.; Curdt, W.; Schühle, U.; Wöhl, H.
Bibcode: 2001ASSL..259..247R
Altcode: 2001dysu.conf..247R
  Experience with the SUMER/SOHO observations of the chromospheric
  dynamics and the reduction of the acquired data is summarized on
  base of the SOHO Joint Operation Program 78 which is focused on the
  variability of the chromosphere and the transition region to the corona.

Title: The Wavelet Analysis of the Solar and Cosmic-Ray Data
Authors: Rybák, J.; Antalová, A.; Storini, M.
Bibcode: 2001SSRv...97..359R
Altcode:
  Results of the wavelet power spectrum (WPS) analysis(which covers
  the 1969 1998 years) obtained using the daily data of the following
  parameters: (i) the Mt. Wilson Magnetic Plage Strength index (MPSI),
  (ii) the solar LDE-type flare index (LDE-FI) and (iii) the Calgary
  cosmic-ray (CR) intensity, are reported for periods ranging between
  64 and 1024 days. The temporal distribution of the WPS during the
  last three solar activity cycles is extremely discontinuous. A clear
  resemblance between the CR and LDE-FI WPS is obtained only for the
  22nd solar activity cycle. Nevertheless, the CR multiperiod peak,
  observed in 1982, can well be identified with the WPS peaks obtained
  in both solar parameters under consideration. In the 21st cycle, we
  found significant the MPSI periods around 850 880 days (2.3 2.4 yr),
  while such periods are present in the LDE-FI data of the 22nd cycle. In
  the CR data we discerned a net periodicity around 650 days (1.7 yr).

Title: Dynamics of the Upper Photosphere: Coherence and Phase Analysis
(CD-ROM Directory: contribs/hanslmei)
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 2001ASPC..223..669H
Altcode: 2001csss...11..669H
  No abstract at ADS

Title: Correlative relationships in an inhomogeneous solar atmosphere
Authors: Gadun, A. S.; Hanslmeier, A.; Kučera, A.; Rybák, J.;
   Wöhl, H.
Bibcode: 2000A&A...363..289G
Altcode:
  We analyse the correlative relationships between various quantities
  derived from 2-D inhomogeneous and time-dependent model atmospheres
  and between selected simulated line parameters to compare them with
  height-dependent correlations derived from spectral observations. We
  detect three photospheric regions: thermal convection, overshooting
  convection and a transition layer. We also show that correlations
  found for the model data and those computed within simulated spectral
  observations are a good testing tool for line formation depths. As
  an example, we examine two criteria, providing heights of line core
  formation in LTE, and conclude that the approach which defines
  this quantity as geometrical height at line center optical depth
  τ<SUB>λ0</SUB> = 1 is likely more suitable for diagnostic purposes
  than the method based on depression contribution function.

Title: Dynamics of the upper solar photosphere
Authors: Hanslmeier, A.; Kučera, A.; Rybák, J.; Neunteufel, B.;
   Wöhl, H.
Bibcode: 2000A&A...356..308H
Altcode:
  The dynamics of the upper solar photosphere was studied by using
  1-D photospheric line spectrograms obtained using the VTT of the
  Observatorio del Teide. Three spectral lines with line core formation
  heights between 250 and 500 km were analyzed. It is clearly seen that at
  these levels the velocity and intensity fields are highly correlated
  but different from the lower lying zone where convective motions
  predominate. This is shown by classical methods (using correlations and
  bisectors) as well as by applying the Hurst exponent method to the data.

Title: 3-D Tomography of the Solar Photosphere
Authors: Hanslmeier, A.; Kucera, A.; Rybak, J.; Wohl, H.
Bibcode: 2000ESASP.463..333H
Altcode: 2000sctc.proc..333H
  No abstract at ADS

Title: On the Rotation Period of the Green Corona
Authors: Rybak, J.
Bibcode: 2000HvaOB..24..135R
Altcode:
  The rotation period of the solar emission corona was determined using
  the Fe XIV 530.3 nm coronal line measurements for the epoch 1947 -
  1991 via the tracer method. An optimized correlation analysis has been
  applied together with a new reliability test for the determination
  of the rotation. The time-latitudinal dependence of the green corona
  rotation rate on the phase of the solar cycle shows a nearly rigid
  latitudinal behaviour for few years before and during cycle minima and
  it is rapidly changing to a differential rotation just after the onset
  of a new solar cycle. This differential rotation profile prolongs till
  the beginning of the descending phase of the cycle and then a slow
  return to the rigid profile follows. Large variations of the green
  corona rotation between these two extremes lead to the conclusion that
  the overall latitudinal and temporal averages of the coronal rotation
  period are not physically correct.

Title: Spectral Statistics of Fe I and Ca II K Lines in the Quiet
    and Active Solar Atmosphere
Authors: Kucera, A.; Brcekova, A. K.; Hanslmeier, A.; Rybak, J.;
   Woehl, H.
Bibcode: 2000HvaOB..24..111K
Altcode:
  Based on two Fe I and Ca II K lines spectra obtained with high spatial
  and spectral resolution we investigated some spectral characteristics
  of these lines in quiet and active regions. In this paper we present
  the behaviour of the central line intensities in different types of
  solar activity. We discuss the obtained results and compare them with
  the results reported by other authors.

Title: The Variations of the Solar Activity and the Low Rigidity
    Cosmic Rays (1969-1998)
Authors: Antalová, A.; Kudela, Karel; Rybak, Jan
Bibcode: 2000ESASP.463..281A
Altcode: 2000sctc.proc..281A
  No abstract at ADS

Title: Two Dimensional Spectral Time Series
Authors: Hanslmeier, A.; Kucera, A.; Rybak, J.; Woehl, H.
Bibcode: 2000HvaOB..24...81H
Altcode:
  We analyze two dimensional time series of solar photospheric
  spectrograms in order to study the dynamics of solar fine structures and
  their evolution. The two dimensional images were obtained by scanning
  over the photosphere. Spectrographic data of this type include a much
  higher information than ordinary images.

Title: Interaction of Sunspots with the Surrounding Plasma - a
    Progress Report
Authors: Woehl, H.; Rybak, J.; Kucera, A.
Bibcode: 2000HvaOB..24..119W
Altcode:
  The historic development of the search for interactions of sunspots
  and solar plasma around them was given in a contribution at the IVth
  Hvar Astrophysical Colloquium (Woehl, 1997). It was concentrated on
  the results of measurements and their reductions performed by Lustig
  and Woehl (1993), showing a dependence of plasma velocity difference
  in front and behind stable sunspots depending on their relative speed
  within the plasma. Since the result obtained was not significant,
  new attempts were started to use MDI/SoHO data and mainly to collect
  data ourselves at telescopes and the horizontal spectrometer of the
  Astronomical Institute of the Slovak Academy of Sciences in Tatranska
  Lomnica, Slovakia. The main difference is that now the plasma velocity
  data are gained by a matrix of fiber optics collecting light at several
  positions around the sunspot. In addition the sunspot positions are
  collected by a different telescope. The reductions of the sunspot
  positions give very reliable rotation data and - as expected - very
  small meridional motions, while the plasma velocity data are not yet
  reliable. Attempts to improve this situation are described.

Title: Fe I and Ca II K Lines in Quiet and Active Regions
Authors: Kucera, A.; Brcekova, K.; Hanslmeier, A.; Rybak, J.; Wohl, H.
Bibcode: 2000ESASP.463..357K
Altcode: 2000sctc.proc..357K
  No abstract at ADS

Title: The Intermittency of the Solar Intermediate-Term Periodicity
    (1969-1998)
Authors: Rybák, J.; Antalova, Anna; Storini, Marisa
Bibcode: 2000ESASP.463..419R
Altcode: 2000sctc.proc..419R
  No abstract at ADS

Title: Chromospheric and Transition Region Dynamics - Reasons
    and Consequences of the Long-period Instrumental Periodicities
    of SUMER/SOHO
Authors: Rybák, J.; Curdt, W.; Kucera, A.; Schühle, U.; Wöhl, H.
Bibcode: 1999ESASP.448..361R
Altcode: 1999mfsp.conf..361R; 1999ESPM....9..361R
  No abstract at ADS

Title: Chromospheric And Transition Region Dynamics - Reasons
    and Consequences of the Short Period Instrumental Periodicities
    of SOHO/SUMER
Authors: Rybak, Jan; Curdt, Werner; Kučera, Ales; Schüehle, Udo;
   Wöehl, Hubertus
Bibcode: 1999ESASP.446..579R
Altcode: 1999soho....8..579R
  The instrumentally caused oscillations of the spectral lines intensity
  and velocity, determined with the SUMER spectrometer onboard SoHO, are
  presented. On examples of two long-term measurements of O I, C II and O
  VI lines, it is shown that the reason of this instrumental effect was
  the insufficient precision of the solar rotation compensation of the
  spectrometer slit position. In both observational runs the standard
  rotation compensation procedure, performed on-line by the instrument,
  was selected for the long-term observations. The minor periodical
  motion of the slit position on the solar disk was taking place during
  such observations and this effect produced the regular changes of the
  measured line intensities and velocities. The significant enhancements
  of the oscillations amplitudes around the frequency 2.56 mHz and its
  harmonics were detected in the cases of observations, performed at
  the disk center. Unfortunately, these frequencies are just in the
  range of the typical oscillations determined till now in the upper
  solar atmosphere ! Consequences of this instrumental effect for SUMER
  measurements of the chromospheric and transition region dynamics
  are discussed. Procedures how to exclude the effect from the data
  post-facto as well as how to modify the future SUMER oscillations
  measurements in order to avoid the effect are proposed

Title: Fiber Optics Device for Solar Spectroscopy - First Measurements
Authors: Kucera, A.; Rybák, J.; Wöhl, H.; Hanslmeier, A.
Bibcode: 1999ASPC..184..319K
Altcode:
  In 1996 we introduced the fiber optics device designed for 2D
  solar spectroscopy (Kucera et al. 1997). Now we present the first
  results obtained within last year. First experiences with wavelength
  calibration, light transmission through the fibers, noise reduction,
  software for reduction of observations and preliminary results of
  reduced scientific data are presented.

Title: SOHO JOP 078 - variability and properties of the quiet sun
    supergranular network and internetwork.
Authors: Kučera, A.; Curdt, W.; Fludra, A.; Rybák, J.; Wöhl, H.
Bibcode: 1999joso.proc..149K
Altcode:
  Study of the variability of the quiet solar atmosphere covering as
  large as possible range of the temperatures using both the 2D imaging
  and 1D spectra was the aim of SOHO JOP 78 observations. Supergranular
  cells were the objects of the authors' main interest. This programme is
  based on the cooperation of several SOHO instruments (SUMER, CDS, MDI,
  EIT) and TRACE. Justification of the JOP, cooperation of instruments
  and specially arranged measurements for the post-facto coalignment of
  data from different instruments are described in this paper.

Title: Correlation of Velocity Fields at Different Heights in the
    Solar Photosphere
Authors: Kucera, A.; Rybák, J.; Wöhl, H.
Bibcode: 1999ASSL..239..219K
Altcode: 1999msa..proc..219K
  A simple experimental method for comparison of the line formation
  heights in the solar photosphere is presented. Several Fe I lines are
  used to test the method.

Title: Heights of formation of FeI photospheric lines
Authors: Kucera, A.; Balthasar, H.; Rybak, J.; Woehl, H.
Bibcode: 1998A&A...332.1069K
Altcode:
  The determination of the location of spectral line-forming layers
  by means of line-depression contribution functions is checked by
  observational tests. The method is based on the assumption that the
  Doppler velocities derived from line bisectors at a given position in
  the profile of a spectral line are related to the actual bulk velocity
  at a particular height in the atmosphere. For a set of six magnetically
  sensitive and non-sensitive Fe I lines (543.45, 557.61, 630.15, 630.25,
  649.50, 649.45 nm) the fluctuations of Doppler velocities along the slit
  of the spectrograph were determined at various Delta lambda from the
  line centers i.e. at various heights in the photosphere. Correlations
  of fluctuations allow us to find those parts in line profiles which
  are formed at identical heights in the photosphere. These experimental
  results are compared with theoretical estimates based on line depression
  contribution functions. The agreement is good and best results are found
  for nonmagnetic strong, but still unsaturated lines. The results support
  the hypothesis that it is possible to ascribe a single height point
  in the solar atmosphere to a given position in a spectral line profile.

Title: Oscillations in Chromosphere and Transition Region Based on
    SUMER Measurements
Authors: Kucera, A.; Curdt, W.; Rybák, J.; Schühle, U.; Wöhl, H.
Bibcode: 1998ASPC..155..351K
Altcode: 1998sasp.conf..351K
  No abstract at ADS

Title: Behaviour of solar active prominence
Authors: Kučera, A.; Rybák, J.; Saniga, M.
Bibcode: 1998PAICz..88..232K
Altcode:
  No abstract at ADS

Title: Measurement of rotational characteristics of sunspots and
    surrounding photospheric plasma.
Authors: Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 1997joso.proc...68K
Altcode:
  No abstract at ADS

Title: Investigation of the Dynamics of Chromosphere and Photosphere
    from Spectra Obtained by Parallel Observations using SUMER on SOHO
    and the VTT on Tenerife
Authors: Curdt, W.; Kucera, A.; Rybak, J.; Schuhle, U.; Wohl, H.
Bibcode: 1997ASPC..118..322C
Altcode: 1997fasp.conf..322C
  This is a preliminary report about parallel observations of
  chromospheric and photospheric spectra in the ultraviolet and visible
  spectral regions using SUMER on SOHO and the VTT on Tenerife performed
  begin of September 1996. The aim is to search for relations of vertical
  velocity patterns in the upper photosphere and chromosphere in the
  solar disk center. In addition temporal changes in these parts of the
  solar atmosphere are investigated.

Title: Dynamical Properties of the Chromosphere and Transition Region
in the Supergranular Network: What Precision of the Spectral Line
    Characteristics Can be Reached?
Authors: Curdt, W.; Kucera, A.; Rybák, J.; Schühle, U.; Wöhl, H.
Bibcode: 1997ESASP.404..307C
Altcode: 1997cswn.conf..307C
  No abstract at ADS

Title: Long Duration Soft X-ray Events and Galactic Cosmic Ray
    Modulation
Authors: Antalova, A.; Rybak, J.; Kudela, K.; Venkatesan, D.
Bibcode: 1996ASPC...95..119A
Altcode: 1996sdit.conf..119A
  No abstract at ADS

Title: Rotation of the solar green corona - Tracer results and
    their reliability
Authors: Rybak, J.
Bibcode: 1996ASPC..109..157R
Altcode: 1996csss....9..157R
  No abstract at ADS

Title: Results of the 1994 and 1995 Eclipse Observations
Authors: Sýkora, I.; Ambros, P.; Kotrc, P.; Minarovjech, M.; Pintér,
   T.; Rybák, J.; Rybanský, M.
Bibcode: 1996RoAJ....6...21S
Altcode:
  No abstract at ADS

Title: On the correlation between daily GCR intensity values and
    LDE-type flare index (1987, 1988, 1990 and 1992)
Authors: Antalova, A.; Kudela, K.; Venkatesan, D.; Rybak, J.
Bibcode: 1995AdSpR..16i.233A
Altcode: 1995AdSpR..16..233A
  The correlation analysis between daily values of Calgary Galactic
  Cosmic Ray intensity (CNI) and LDE-type flare index (FI) reveals
  the following results: in all years under consideration, the CNI-FI
  anticorrelation is small, but statistically significant. The yearly
  CNI-FI trend depends on yearly heliospherical conditions and on their
  22-year cyclical changes. At the onset of the 22-nd cycle (in 1987) the
  CNI-FI relation had broad minimum, similar to the result for non-flare
  SXR background corona in 1987. In 1988 and 1992 the typical short-term
  CNI-FI lag (from - 1 to - 3 days) was found, indicating the presence
  of local heliospherical CNI modulation sources. In 1990, the CNI-FI
  correlation has two comparable, large minima at - 22 as well as -
  9 day CNI lags. Such double peak form of the 1990's CNI-FI minimum
  is consistent with the existence of two, amplitudinally balanced CNI
  modulation sources in the 1990's heliosphere. The first source seems
  to be a substantial Global Merged Interaction Region (GMIR) located
  in the outer heliosphere (producing the - 22 day CNI lag). The second
  source was a typical local heliospherical structure, indicated by
  short-term CNI lags.

Title: Daily values of the solar SXR background and modulation of GCRs
    (1987, 1988, 1990 and 1992)
Authors: Antalova, A.; Kudela, K.; Venkatesan, D.; Rybak, J.
Bibcode: 1995AdSpR..16i.237A
Altcode: 1995AdSpR..16..237A
  We present here the results of the intercorrelation analysis between
  the daily Calgary Galactic Cosmic Ray intensity values (CNI) and daily
  solar SXR background (XBG - unresolved full-sun SXR GOES flux). The
  anticorrelation between CNI and XBG is statistically significant
  for 1987, 1988 and 1992 sequences. In 1990, no anticorrelation
  between CNI and XBG was found. The latter fact gives evidence for
  the Global Merged Interaction Region (GMIR) being the most dominant
  GCR modulation structure of the 1990's outer heliospherical system,
  while local heliospherical structures seemed to play the secondary role.

Title: Observations of Fe I lines in the quiet solar photosphere.
Authors: Kucera, A.; Rybak, J.; Woehl, H.
Bibcode: 1995A&A...298..917K
Altcode:
  We investigate three sets of spectra with high spatial and spectral
  resolution. Each set consists of four spectra taken simultaneously
  with the Vacuum Tower Telescope at Izana, Tenerife. The main spectral
  characteristics (continuum intensity I_c_; full width at half
  maximum FWHM; residual intensity I_o_) were computed for 5 magnetic
  and non-magnetic Fe I lines (5434.543 A, 5576.099 A, 6301.497 A,
  6302.499 A, 6494.994 A). Our results allow a diagnosis of the solar
  atmosphere in the vertical (two main levels of line formation)
  and horizontal directions (71 arcseconds). The spectra cover both
  interior parts of supergranular cells (purely quiet regions, PQR) and
  cell boundaries (moderate active regions, MAR). The main results are:
  (1) We find a different continuum intensity distribution for PQRs
  and MARs, which reflects the existence of different patterns in these
  regions. The difference is also evident in the rms residual intensity
  fluctuation. (2) A significant minimum of the residual intensity
  fluctuations (δI_o_/I_c_)_rms_ occurs at a height of about 300km. (3)
  At all heights of the PQRs the line widths FWHM in the intergranular
  lanes are larger than the mean line width; those in the granules
  are smaller. This variation of the FWHM is influenced by a magnetic
  effect near the centres of the intergranular lanes (reduced FWHM),
  and by the effect of convection in granules (enhanced FWHM). (4)
  The correlation &lt;I_c_, I_o_&gt; reverses its sign at a height of
  about 250km. The anticorrelation in the range 300-500km indicates a
  non-convective structure, different from the photospheric granular
  pattern found earlier.

Title: Daily Values of the Solar SXR Background and Galactic Cosmic
    Ray Modulation (1968-1972)
Authors: Antalová, A.; Rybák, J.; Kudela, K.; Venkatesan, D.
Bibcode: 1995ICRC....4..534A
Altcode: 1995ICRC...24d.534A
  No abstract at ADS

Title: Role of LDE-Type Flares in the GCR Modulation (1969-1972)
Authors: Antalová, A.; Rybák, J.; Kudela, K.; Venkatesan, D.
Bibcode: 1995ICRC....4..530A
Altcode: 1995ICRC...24d.530A
  No abstract at ADS

Title: Cosmic-Ray Modulation and Long-Duration Solar Flare Events
Authors: Kudela, K.; Antalova, A.; Venkatesan, D.; Rybak, J.
Bibcode: 1994SoPh..154..371K
Altcode:
  The correlation between the long-term intensity variations of cosmic
  rays at neutron monitor energies and the LDE index measure of solar
  flares with long-lasting soft X-ray emissions is reported. Three
  subsequent solar cycles, 20-22, are taken into account and half-monthly
  data are analyzed. Possible explanation of this correlation is discussed
  in terms of the recent concepts of cosmic-ray modulation, in particular
  with merged interaction regions affecting the cosmic-ray intensity.

Title: Rotational characteristics of the green solar corona: 1964 1989
Authors: Rybak, J.
Bibcode: 1994SoPh..152..161R
Altcode: 1994svs..coll..161R; 1994IAUCo.143..161R
  Fe XIV 5303 å coronal emission line observations have been used for
  the estimation of the rotation behaviour of the green solar corona. A
  homogeneous data set, created from measurements carried out within the
  framework of the world-wide coronagraphic network, has been examined
  with a correlation analysis to reveal the averaged synodic rotation
  period as a function of latitude and time over the epoch from 1964
  to 1989.

Title: Long Duration Solar Flare Events and Cosmic Ray Modulation
    (1969-1992)
Authors: Antalova, A.; Kudela, K.; Venkatesan, D.; Rybak, J.
Bibcode: 1994scs..conf..499A
Altcode: 1994IAUCo.144..499A
  The authors present the results of a correlation analysis between the
  galactic cosmic ray intensity decrease (as observed on Calgary neutron
  monitor station) and the occurrence of SXR long-lasting (LDE-type)
  solar flares represented by the LDE-type flare index FI. It is shown,
  that for the solar cycle with the lower monthly values of FI (the
  21-st solar cycle) the correlation coefficient is slighter (about 0.4)
  as compared to the cycles with the higher LDE-type flare activity
  (about 0.6, in the 20-th and the 22-nd cycles).

Title: Rotational Characteristics of the Green Solar Corona: 1947-1991
Authors: Rybak, J.; Rusin, V.; Rybansky, M.
Bibcode: 1994scs..conf..139R
Altcode: 1994IAUCo.144..139R
  Fe XIV 530.3 nm coronal emission line observations have been used for
  the estimation of the green solar corona rotation. A homogeneous data
  set, created from measurements of the world-wide coronagraphic network,
  has been examined with a help of correlation analysis to reveal the
  averaged synodic rotation period as a function of latitude and time
  over the epoch from 1947 to 1991.

Title: FeXIV Line Emission Polarization of the July 11, 1991 Solar
    Corona
Authors: Sykora, J.; Rybak, J.; Ambroz, P.
Bibcode: 1994scs..conf..541S
Altcode: 1994IAUCo.144..541S
  High resolution images, obtained during July 11, 1991 total solar
  eclipse, allowed to estimate the degree of solar corona polarization
  in the light of Fe XIV 530.3 nm emission line and in the white light,
  as well. Very preliminary analysis reveals remarkable differences in
  the degree of polarization for both sets of data, particularly as for
  level of polarization and its distribution around the Sun's limb.

Title: Mass Ejections from Chromosphere to Corona: Results from a
    Spectral Analysis
Authors: Kučera, A.; Rybák, J.; Minaroviech, M.
Bibcode: 1994emsp.conf..147K
Altcode:
  No abstract at ADS

Title: Magnetic and nonmagnetic line profiles in solar quiet and
    active regions
Authors: Kučera, A.; Rybák, J.; Wöhl, H.
Bibcode: 1994smf..conf..291K
Altcode:
  No abstract at ADS

Title: IBM PCs also for the Solar Observations with Adaptive Optics?
Authors: Ambrôz, J.; Rybák, J.
Bibcode: 1994ESOC...48..167A
Altcode: 1994aao..conf..167A
  No abstract at ADS

Title: A new instrumentation project for the Lomnicky stit coronal
    station
Authors: Rybak, J.
Bibcode: 1993CoSkS..23..129R
Altcode:
  A proposal of a new telescope/auxiliary instrumentation system for the
  solar coronal station at Lomnicky Stit (2632 m asl) is described in
  both the general concept and some particular technical details. The
  main aim of the system is to observe the near-limb photospheric and
  chromospheric layers of the solar atmosphere by the white-light and
  narrow-band imaging, as well as to perform the visible and near-infrared
  spectroscopy and spectropolarimetry of the parts of solar disk already
  mentioned. These sorts of data, measured simultaneously with the coronal
  emission line profiles which are regularly obtained at this time by
  coronagraph, could give us a great amount of physical information about
  the solar activity events (such as the height distribution of energy,
  mass, magnetic fields and their time evolution). The initial ideas and
  motivation of the project are explained. The parameters of the system
  components - refractors, narrow band filters, focal plane detectors
  and fibre optics positioners, telescope-spectrograph coupling via
  fiber optics, spectrographs, detectors and computers for the control of
  observations and the data acquisition - are discussed. TV CCD detectors
  connected with the advanced frame grabbers and the IBM PC computers are
  especially taken into account for the data acquisition. We also briefly
  mention advantages and disadvantages of the system as a whole. Finally,
  the future prospects of the project proposal are briefly described.

Title: A new instrumentation project for the Lomnický štít
    coronal station.
Authors: Rybák, J.
Bibcode: 1993CoSka..23..129R
Altcode:
  No abstract at ADS

Title: Numerical analysis of a static cylindrically symmetric Abelian
    Higgs sunspot
Authors: Klacka, J.; Saniga, M.; Rybak, J.
Bibcode: 1992CoSka..22..107K
Altcode:
  We present the exact numerical solutions of the Ginzburg-Landau
  equations for the case of a static, cylindrically symmetric Abelian
  Higgs sunspot model. The method of solving of these equations is
  presented in detail, and the behaviour of the Higgs field amplitude,
  magnetic field strength, electric current density, as well as of the
  diagonal components of the stress-energy tensor are illustrated for
  spots carrying one to five flux quanta.

Title: The journey into the centre of the Sun.
Authors: Neslusan, L.; Rybák, J.
Bibcode: 1992Kozmo..23....8N
Altcode:
  No abstract at ADS

Title: Hot mass transport in the solar active prominence
Authors: Kucera, A.; Saniga, M.; Rybak, J.
Bibcode: 1992AIPC..267..160K
Altcode: 1992ecsa.work..160K
  On October 16, 1990, a remarkable active prominence was observed,
  in Hα line, during 113 minutes. The time gap between successive
  profile recordings was 20 seconds and 339 profiles have been recorded
  together. We focused our attention on Doppler shift measurements as
  well as on significant changes in the prominence intensity. We also
  give a possible explanation of a sudden increment in the intensity of
  Hα line in dependence on the fact if the whole profile originates in
  one particular place in the prominence or if it is a superposition of
  the radiation incident from two different, physically unrelated parts
  of the prominence.

Title: The horizontal solar telescope with spectrograph at Stará
    Lesná Observatory
Authors: Kucera, A.; Rybak, J.; Minarovjech, M.; Novocky, D.;
   Saniga, M.
Bibcode: 1990Ap&SS.171..279K
Altcode:
  The construction and the optical design as well as the controlling
  electronic device and the spectrum recording of the new horizontal
  solar telescope with the spectrograph of the Astronomical Institute of
  Slovak Academy of Sciences are described. Also some of its adjustments
  and improvements are briefly mentioned.

Title: Globules and star formation.
Authors: Rybák, J.
Bibcode: 1988Kozmo..19...11R
Altcode:
  No abstract at ADS

Title: Can small-scale bipolar structures originate in the solar
    atmosphere ?
Authors: Saniga, M.; Kučera, A.; Novocký, D.; Rybák, J.
Bibcode: 1986CoSka..15..683S
Altcode:
  Using the formalism of the magnetohydrodynamics shock waves the simple
  model of the origin of small-scale bipolar structures in a magnetized
  plasma is outlined. It is shown that there are regions in the atmosphere
  of the Sun where such object can naturally occur. Properties of these
  structures and their typical dimension are examined.

