berlicki

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Author name code: berlicki
ADS astronomy entries on 2022-09-14
author:"Berlicki, Arkadiusz" OR author:"Berlicki, Arek"

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

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Title: A first comparison of FLARIX flare simulations with the MSDP
H-alpha spectral observations on very short time scales
Authors: Heinzel, Petr; Kasparova, Jana; Berlicki, Arkadiusz;
Radziszewski, Krzysztof; Rudawy, Pawel
2022cosp...44.2560H Altcode:
We present first results of a comparative analysis of high temporal
resolution MSDP H$\alpha$ observations of a compact solar flare with
results of radiation-hydrodynamical simulations performed using the
FLARIX code. X-ray spectral observations of a compact C1 GOES-class
flare obtained from RHESSI satellite were used to estimate physical
parameters of the electron beams transporting the energy from the
reconnection site down to the chromosphere. These parameters are then
used for data-driven FLARIX simulations. A small size of the flare
and its simple structure allowed us to assume a single-loop geometry
which significantly simplified the modelling and analysis of the
whole event. Using the MSDP imaging spectrograph at Bia{\l}k\'{o}w
observatory, it was possible to compare the recorded H$\alpha$
line emission with that obtained from FLARIX simulations, on short
time-scales down to 50 ms.

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Title: Geometry and dynamics of cool flare loops observed by IRIS
Authors: Mikuła, Katarzyna; Heinzel, Petr; Berlicki, Arkadiusz
2022cosp...44.2414M Altcode:
Flare loops represent a well-known, inseparable part of solar
flares. They are observed mainly during the gradual phase of the flares,
being rooted in flare ribbons. They can form an entire arcade which
evolves in the corona, sometimes for hours. The loops are visible
in a wide range of temperature bands, from X-rays (hot flare loops)
to temperatures of the cool chromospheric-type plasma seen in the
ultraviolet and optical spectrum (cool flare loops). We present
results of our analysis of cool flare loops observed during the gradual
phase of M6.5 solar flare on June 22, 2015 based on the ultraviolet
observations obtained by Interface Region Imaging Spectrograph
(IRIS). Detailed investigation of these loops, made on the basis of
Mg II line profiles, was presented in Mikuła et al. (2017). Mg II
line profiles were modelled using the standard cloud model method
that allowed us obtaining simultaneously the physical parameters
characteridsing the moving plasma inside selected loops, i.e. the
velocity along the line-of-sight, microturbulent velocity, optical
thickness, and the line source function. Here we present a next step
of the work — reconstruction of the true shape of flare loops based
on the geometric method of Loughhead, Wang and Blows (1983). Based
on two-dimensional images of a given loop structure located on
the solar disk or at the limb, we can obtain its true orientation
and its size. The shape of the analysed loops was determined mainly
from IRIS slit-jaw images at 1330, 1400 and 2796 \AA{}, supplemented
with SDO/AIA 171 \AA{} images in some cases. Using basic geometry,
we reconstructed the shape of selected loops in the three-dimensional
space. Based on the method presented in Loughhead and Bray (1984) we
were able to derive the so-called true velocity of the plasma flows,
i.e. the velocity along the loop axis. The results obtained for each
loop were then compared with the free fall velocities.

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Title: New Insight into UV Compact Bursts - Statistical Analysis of
IRIS Data
Authors: Berlicki, Arkadiusz; Heinzel, Petr; Schmieder, Brigitte;
Michalina Litwicka, M.
2022cosp...44.2532B Altcode:
UV small-scale brightenings have been frequently observed by IRIS in
both NUV and FUV channels. They appear as compact and intense, but short
lived bursts visible within the solar active regions. Some of them seem
to be closely connected with the well-known Ellerman bombs and so-called
IRIS bombs. Based on the IRIS observations of many compact bursts
obtained in chromospheric Mg II h and k lines, Mg II triplet and FUV
lines we present detailed statistical analysis of these phenomena. In
the work of Grubecka et al. (2016), five different compact bursts (CBs)
were selected and analysed in detail. NLTE semi-empirical models of
them were constructed based on their spectral characteristics in the
Mg II h and k lines. In addition, they were preliminarily categorised
into three types. In present work we extend previous analysis and
investigate statistical diversity of Mg II lines of UV bursts and
their visibility in FUV lines such as Si IV or C II. IRIS database
from 2013-2018 was searched for dense rasters of active and emerging
flux regions containing spectra in Mg II, C II and Si IV. A next step
was to reconstruct full rasters in which we were looking for compact
brightenings with size of the order of one arcsec. We found more than
two thousands CBs using criteria based on specific parameters of the
Mg II k line profile. In addition, we analysed also the emission of
Mg II UV triplet and some parameters of Si IV and C II lines. This
database allowed us to make a novel statistical analysis of all bursts
and we categorised them in previously defined three types, depending on
their Mg II line profiles shapes. We also investigated the correlations
between the emission of Mg II lines, "hotter" Si IV lines, and C II
lines in order to find which of these events are linked with IRIS bombs
(Peter et al. 2014). Finally, we analysed some observables of those
UV bursts, which can be defined as candidates for Ellerman bombs.

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Title: Diagnostics of The Prominence Plasma Based on IRIS, H-alpha
and ALMA Observations
Authors: Berlicki, Arkadiusz; Bárta, Miroslav; Gunár, Stanislav;
Heinzel, Petr; Jejcic, Sonja; Radziszewski, Krzysztof; Rudawy, Pawel
2022cosp...44.2543B Altcode:
Solar prominences are now commonly observed above the solar limb in
different spectral bands and recent developments of new observing
techniques allow us to detect them from radio to far-UV ranges. In
addition to often used spectral observations in optical and UV,
ALMA interferometer obtained high-resolution images of a quiescent
solar prominence at 3 millimeters (Band 3) during the coordinated
space and ground-based observing campaign. For the first time
high-resolution observations of such structures in the millimeter
radio domain are available. The fine structures of this prominence was
also observed in the UV with IRIS and in the H$\alpha$ line with the
MSDP of Wroc{\l}aw Observatory. Both UV and H$\alpha$ data contains
not only images, but also spectra which makes the available dataset
extremely valuable. Moreover, all UV, H$\alpha$ and ALMA observations
are co-temporal which gives an unprecedented opportunity for a novel
diagnostic, not available so far. In this work we present analysis
of the prominence spectral characteristics in H$\alpha$ and UV Mg
II lines, looking for the statistical dependence between different
parameters (metrics) in the line profiles. This combined data is
then used for determination of plasma parameters in the prominence
fine structures. In addition, UV and H$\alpha$ spectral maps are
compared with the brightness temperature mosaics from ALMA, providing
an additional constraint on the plasma kinetic temperature. Detailed
diagnostics is then based on extensive NLTE numerical simulations of
the radiative transfer inside heterogeneous prominence structures.

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Title: ALMA as a Prominence Thermometer: First Observations
Authors: Heinzel, Petr; Berlicki, Arkadiusz; Bárta, Miroslav; Rudawy,
Paweł; Gunár, Stanislav; Labrosse, Nicolas; Radziszewski, Krzysztof
2022ApJ...927L..29H Altcode: 2022arXiv220212761H
We present first prominence observations obtained with Atacama
Large Millimeter Array (ALMA) in Band 3 at the wavelength of
3 mm. High-resolution observations have been coaligned with the
MSDP Hα data from Wrocław-Białków large coronagraph at similar
spatial resolution. We analyze one particular cotemporal snapshot,
first calibrating both ALMA and MSDP data and then demonstrating a
reasonable correlation between both. In particular, we can see quite
similar fine-structure patterns in both ALMA brightness-temperature maps
and MSDP maps of Hα intensities. Using ALMA, we intend to derive the
prominence kinetic temperatures. However, having current observations
only in one band, we use an independent diagnostic constraint, which
is the Hα line integrated intensity. We develop an inversion code and
show that it can provide realistic temperatures for brighter parts of
the prominence where one gets a unique solution, while within faint
structures, such inversion is ill conditioned. In brighter parts,
ALMA serves as a prominence thermometer, provided that the optical
thickness in Band 3 is large enough. In order to find a relation between
brightness and kinetic temperatures for a given observed Hα intensity,
we constructed an extended grid of non-LTE prominence models covering
a broad range of prominence parameters. We also show the effect of
the plane-of-sky filling factor on our results.

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Title: The first coronal mass ejection observed in both visible-light
and UV H I Ly-α channels of the Metis coronagraph on board Solar
Orbiter
Authors: Andretta, V.; Bemporad, A.; De Leo, Y.; Jerse, G.; Landini,
F.; Mierla, M.; Naletto, G.; Romoli, M.; Sasso, C.; Slemer, A.;
Spadaro, D.; Susino, R.; Talpeanu, D. -C.; Telloni, D.; Teriaca, L.;
Uslenghi, M.; Antonucci, E.; Auchère, F.; Berghmans, D.; Berlicki,
A.; Capobianco, G.; Capuano, G. E.; Casini, C.; Casti, M.; Chioetto,
P.; Da Deppo, V.; Fabi, M.; Fineschi, S.; Frassati, F.; Frassetto,
F.; Giordano, S.; Grimani, C.; Heinzel, P.; Liberatore, A.; Magli, E.;
Massone, G.; Messerotti, M.; Moses, D.; Nicolini, G.; Pancrazzi, M.;
Pelizzo, M. -G.; Romano, P.; Schühle, U.; Stangalini, M.; Straus,
Th.; Volpicelli, C. A.; Zangrilli, L.; Zuppella, P.; Abbo, L.; Aznar
Cuadrado, R.; Bruno, R.; Ciaravella, A.; D'Amicis, R.; Lamy, P.;
Lanzafame, A.; Malvezzi, A. M.; Nicolosi, P.; Nisticò, G.; Peter,
H.; Plainaki, C.; Poletto, L.; Reale, F.; Solanki, S. K.; Strachan,
L.; Tondello, G.; Tsinganos, K.; Velli, M.; Ventura, R.; Vial, J. -C.;
Woch, J.; Zimbardo, G.
2021A&A...656L..14A Altcode:
Context. The Metis coronagraph on board Solar Orbiter offers a new
view of coronal mass ejections (CMEs), observing them for the first
time with simultaneous images acquired with a broad-band filter in
the visible-light interval and with a narrow-band filter around the
H I Ly-α line at 121.567 nm, the so-called Metis UV channel. 
Aims: We show the first Metis observations of a CME, obtained on 16
and 17 January 2021. The event was also observed by the EUI/FSI imager
on board Solar Orbiter, as well as by other space-based coronagraphs,
such as STEREO-A/COR2 and SOHO/LASCO/C2, whose images are combined here
with Metis data. Methods: Different images are analysed here
to reconstruct the 3D orientation of the expanding CME flux rope using
the graduated cylindrical shell model. This also allows us to identify
the possible location of the source region. Measurements of the CME
kinematics allow us to quantify the expected Doppler dimming in the
Ly-α channel. Results: Observations show that most CME features
seen in the visible-light images are also seen in the Ly-α images,
although some features in the latter channel appear more structured
than their visible-light counterparts. We estimated the expansion
velocity of this event to be below 140 km s−1. Hence,
these observations can be understood by assuming that Doppler dimming
effects do not strongly reduce the Ly-α emission from the CME. These
velocities are comparable with or smaller than the radial velocities
inferred from the same data in a similar coronal structure on the
east side of the Sun. Conclusions: The first observations by
Metis of a CME demonstrate the capability of the instrument to provide
valuable and novel information on the structure and dynamics of these
coronal events. Considering also its diagnostics capabilities regarding
the conditions of the ambient corona, Metis promises to significantly
advance our knowledge of such phenomena. Movies are available at <A
href="https://www.aanda.org/10.1051/0004-6361/202142407/olm">https://www.aanda.org</A>

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

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Title: Metis - Solar Orbiter Topical Team on "Modelling of CME
propagation/evolution in corona and solar wind in connection with
Space Weather"
Authors: Bemporad, A.; Banerjee, D.; Berlicki, A.; Biondo, R.; Boe,
B.; Calchetti, D.; Capuano, G.; De Leo, Y.; Del Moro, D.; Feng, L.;
Foldes, R.; Frassati, F.; Frazin, R. A.; Giovannelli, L.; Giunta,
A. S.; Heinzel, P.; Ippolito, A.; Janvier, M.; Jerse, G.; Kilpua,
K. E. J.; Laurenza, M.; Lloveras, D.; Magdalenic, J.; Mancuso, S.;
Messerotti, M.; Mierla, M.; Nandy, D.; Napoletano, G.; Nuevo, F.;
Pagano, P.; Pinto, R.; Plainaki, C.; Reale, F.; Romoli, M.; Rodriguez,
L.; Slemer, A.; Spadaro, D.; Susino, R.; Stangalini, M.; Vainio,
R. O.; Valori, G.; Vásquez, A. M.; West, M. J.
2020AGUFMSH0360027B Altcode:
Despite the current availability of multi-spacecraft observations of
Coronal Mass Ejections (CMEs) and their interplanetary counterpart
(ICMEs), at present we still don't understand which physical phenomena
are driving their expansion and propagation phases. This also limits
our understanding on how CMEs (observed with remote sensing data)
become ICMEs (observed in situ), how they interact with the background
solar wind, and how their final geo-effectiveness can be modified
during their interplanetary evolution. Such problems match some of
the scientific objectives of the Solar Orbiter Science Activity Plan
and of the Metis coronagraph. Thanks to its multi-channel capability,
Metis (acquiring images in the visible light and at the same time in
the UV HI Lyman-alpha emission) will really provide an unprecedented
view of CMEs and in particular of their thermodynamic evolution. At
closest approaches to the Sun (in the nominal mission), Metis will
acquire high spatial resolution and/or temporal cadence multi-channel
images of CMEs. Farther from the Sun, Metis will shed light on the
early Interplanetary propagation of CMEs. Later on (in the extended
mission) Metis will observe for the first time the CME/ICME propagation
out-of-ecliptic. These novelties will be combined with the unique
vantage point that will be offered by the Solar Orbiter spacecraft,
and supported with valuable data acquired by other on-board remote
sensing (e.g. SPICE, EUI, SoloHI) and in situ (e.g. EPD, MAG,
SWA, RPW) instruments. In this contribution we present the ongoing
activities of the Metis Topical Team on "CME/ICME propagation", (<A
href="http://metis.oato.inaf.it/topical_teams.html">http://metis.oato.inaf.it/topical_teams.html</A>),
an international working group recently established and gathering
scientists from different countries, experts of both in-situ and remote
sensing observations, as well as numerical simulations, and we summarize
the main science objectives discussed during the last months.

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

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Title: Optical design of the multi-wavelength imaging coronagraph
Metis for the solar orbiter mission
Authors: Fineschi, S.; Naletto, G.; Romoli, M.; Da Deppo, V.;
Antonucci, E.; Moses, D.; Malvezzi, A. M.; Nicolini, G.; Spadaro,
D.; Teriaca, L.; Andretta, V.; Capobianco, G.; Crescenzio, G.;
Focardi, M.; Frassetto, F.; Landini, F.; Massone, G.; Melich, R.;
Nicolosi, P.; Pancrazzi, M.; Pelizzo, M. G.; Poletto, L.; Schühle,
U.; Uslenghi, M.; Vives, S.; Solanki, S. K.; Heinzel, P.; Berlicki,
A.; Cesare, S.; Morea, D.; Mottini, S.; Sandri, P.; Alvarez-Herrero,
A.; Castronuovo, M.
2020ExA....49..239F Altcode: 2020ExA...tmp...14F
This paper describes the innovative optical design of the Metis
coronagraph for the Solar Orbiter ESA-NASA mission. Metis is a
multi-wavelength, externally occulted telescope for the imaging
of the solar corona in both the visible and ultraviolet wavelength
ranges. Metis adopts a novel occultation scheme for the solar disk,
that we named "inverse external occulter", for reducing the extremely
high thermal load on the instrument at the spacecraft perihelion. The
core of the Metis optical design is an aplanatic Gregorian telescope
common to both the visible and ultraviolet channels. A suitable
dichroic beam-splitter, optimized for transmitting a narrow-band in
the ultraviolet (121.6 nm, HI Lyman-α) and reflecting a broadband
in the visible (580-640 nm) spectral range, is used to separate the
two optical paths. Along the visible light optical path, a liquid
crystal electro-optical modulator, used for the first time in space,
allows making polarimetric measurements.

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Title: A Search for High-Frequency Coronal Brightness Variations in
the 21 August 2017 Total Solar Eclipse
Authors: Rudawy, P.; Radziszewski, K.; Berlicki, A.; Phillips,
K. J. H.; Jess, D. B.; Keys, P. H.; Keenan, F. P.
2019SoPh..294...48R Altcode: 2019arXiv190306076R
We report on a search for short-period intensity variations in the
green-line (Fe XIV 530.3 nm) emission from the solar corona during the
21 August 2017 total eclipse viewed from Idaho in the United States. Our
experiment was performed with a much more sensitive detection system,
and with better spatial resolution, than on previous occasions (1999
and 2001 eclipses), allowing fine details of quiet coronal loops and
an active-region loop system to be seen. A guided 200-mm-aperture
Schmidt-Cassegrain telescope was used with a state-of-the-art CCD
camera having 16-bit intensity discrimination and a field-of-view
(0.43∘×0.43∘) that encompassed approximately
one third of the visible corona. The camera pixel size was 1.55
arcseconds, while the seeing during the eclipse enabled features of
≈2 arcseconds (1450 km on the Sun) to be resolved. A total of 429
images were recorded during a 122.9 second portion of the totality at
a frame rate of 3.49 s−1. In the analysis, we searched
particularly for short-period intensity oscillations and travelling
waves, since theory predicts fast-mode magneto-hydrodynamic (MHD) waves
with short periods may be important in quiet coronal and active-region
heating. Allowing first for various instrumental and photometric
effects, we used a wavelet technique to search for periodicities in some
404 ,000 pixels in the frequency range 0.5 -1.6 Hz (periods 2 seconds
to 0.6 seconds). We also searched for travelling waves along some 65
coronal structures. However, we found no statistically significant
evidence in either. This negative result considerably refines the
limit that we obtained from our previous analyses, and it indicates
that future searches for short-period coronal waves may be better
directed towards Doppler shifts as well as intensity oscillations.

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Title: Solar Ultraviolet Bursts
Authors: Young, Peter R.; Tian, Hui; Peter, Hardi; Rutten, Robert J.;
Nelson, Chris J.; Huang, Zhenghua; Schmieder, Brigitte; Vissers, Gregal
J. M.; Toriumi, Shin; Rouppe van der Voort, Luc H. M.; Madjarska, Maria
S.; Danilovic, Sanja; Berlicki, Arkadiusz; Chitta, L. P.; Cheung, Mark
C. M.; Madsen, Chad; Reardon, Kevin P.; Katsukawa, Yukio; Heinzel, Petr
2018SSRv..214..120Y Altcode: 2018arXiv180505850Y
The term "ultraviolet (UV) burst" is introduced to describe small,
intense, transient brightenings in ultraviolet images of solar active
regions. We inventorize their properties and provide a definition
based on image sequences in transition-region lines. Coronal signatures
are rare, and most bursts are associated with small-scale, canceling
opposite-polarity fields in the photosphere that occur in emerging flux
regions, moving magnetic features in sunspot moats, and sunspot light
bridges. We also compare UV bursts with similar transition-region
phenomena found previously in solar ultraviolet spectrometry and
with similar phenomena at optical wavelengths, in particular Ellerman
bombs. Akin to the latter, UV bursts are probably small-scale magnetic
reconnection events occurring in the low atmosphere, at photospheric
and/or chromospheric heights. Their intense emission in lines with
optically thin formation gives unique diagnostic opportunities
for studying the physics of magnetic reconnection in the low solar
atmosphere. This paper is a review report from an International Space
Science Institute team that met in 2016-2017.

---------------------------------------------------------
Title: IRIS Observations and Modeling of MGII Flare Loops
Authors: Heinzel, Petr; Berlicki, Arkadiusz; Mikula, Katarzyna;
Liu, Wenjuan
2018cosp...42E1423H Altcode:
Solar chromospheric flares are often associated with cool loops which
are rooted in the ribbons. These loops extend into coronal altitudes
and usually are modelled as prominence-like structures illuminated from
the solar disk. The loops exhibit large down-flows (coronal rain) and
they evolve in time in accordance with the characteristic cooling times
of the loop plasmas. Cool loops are visible in various spectral lines
formed at chromospheric temperatures. We exploit novel observations
of such loops in MgII h and k lines obtained by the IRIS satellite,
analyse selected observations where the cool loops are well visible
and studytheir temporal evolution. Our spectroscopic diagnostics is
based on 2D non-LTE modelling ofMgII lines in flare loops taking into
account the flows along the loops. From these models wedetermine various
plasma parameters and the rates of radiation cooling. These results
allow usto better understand the structure, dynamics and evolution of
cool flare loops.

---------------------------------------------------------
Title: Chromospheric Response during the Precursor and the Main
Phase of a B6.4 Flare on 2005 August 20
Authors: Awasthi, Arun Kumar; Rudawy, Pawel; Falewicz, Robert;
Berlicki, Arkadiusz; Liu, Rui
2018ApJ...858...98A Altcode: 2018arXiv180402632A
Solar flare precursors depict a constrained rate of energy release,
in contrast to the imminent rapid energy release, which calls for a
different regime of plasma processes to be at play. Due to the subtle
emission during the precursor phase, its diagnostics remain delusive,
revealing either nonthermal electrons (NTEs) or thermal conduction to
be the driver. In this regard, we investigate the chromospheric response
during various phases of a B6.4 flare on 2005 August 20. Spatiotemporal
investigation of flare ribbon enhancement during the precursor phase,
carried out using spectra images recorded in several wavelength
positions on the Hα line profile, revealed its delayed response (180
s) compared to the X-ray emission, as well as a sequential increment
in the width of the line profile, which are indicative of a slow
heating process. However, the energy contained in the Hα emission
during the precursor phase can reach as high as 80% of that estimated
during the main phase. Additionally, the plasma hydrodynamics during
the precursor phase, resulting from the application of a single-loop
one-dimensional model, revealed the presence of a power-law extension
in the model-generated X-ray spectra, with a flux lower than the
RHESSI background. Therefore, our multiwavelength diagnostics and
hydrodynamical modeling of the precursor emission indicates the
role of a two-stage process. First, reconnection-triggered NTEs,
although too small in flux to overcome the observational constraints,
thermalize in the upper chromosphere. This leads to the generation
of a slow conduction front, which causes plasma heating during the
precursor phase.

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Title: METIS: the visible and UV coronagraph for solar orbiter
Authors: Romoli, M.; Landini, F.; Antonucci, E.; Andretta, V.;
Berlicki, A.; Fineschi, S.; Moses, J. D.; Naletto, G.; Nicolosi, P.;
Nicolini, G.; Spadaro, D.; Teriaca, L.; Baccani, C.; Focardi, M.;
Pancrazzi, M.; Pucci, S.; Abbo, L.; Bemporad, A.; Capobianco, G.;
Massone, G.; Telloni, D.; Magli, E.; Da Deppo, V.; Frassetto, F.;
Pelizzo, M. G.; Poletto, L.; Uslenghi, M.; Vives, S.; Malvezzi, M.
2017SPIE10563E..1MR Altcode:
METIS coronagraph is designed to observe the solar corona with an
annular field of view from 1.5 to 2.9 degrees in the visible broadband
(580-640 nm) and in the UV HI Lyman-alpha, during the Sun close
approaching and high latitude tilting orbit of Solar Orbiter. The
big challenge for a coronagraph is the stray light rejection. In
this paper after a description of the present METIS optical design,
the stray light rejection design is presented in detail together with
METIS off-pointing strategies throughout the mission. Data shown in this
paper derive from the optimization of the optical design performed with
Zemax ray tracing and from laboratory breadboards of the occultation
system and of the polarimeter.

---------------------------------------------------------
Title: Time Variations of Observed Hα Line Profiles and Precipitation
Depths of Nonthermal Electrons in a Solar Flare
Authors: Falewicz, Robert; Radziszewski, Krzysztof; Rudawy, Paweł;
Berlicki, Arkadiusz
2017ApJ...847...84F Altcode: 2017arXiv170809797F
We compare time variations of the Hα and X-ray emissions observed
during the pre-impulsive and impulsive phases of the C1.1-class solar
flare on 2013 June 21 with those of plasma parameters and synthesized
X-ray emission from a 1D hydrodynamic numerical model of the flare. The
numerical model was calculated assuming that the external energy is
delivered to the flaring loop by nonthermal electrons (NTEs). The Hα
spectra and images were obtained using the Multi-channel Subtractive
Double Pass spectrograph with a time resolution of 50 ms. The X-ray
fluxes and spectra were recorded by RHESSI. Pre-flare geometric and
thermodynamic parameters of the model and the delivered energy were
estimated using RHESSI data. The time variations of the X-ray light
curves in various energy bands and those of the Hα intensities and
line profiles were well correlated. The timescales of the observed
variations agree with the calculated variations of the plasma parameters
in the flaring loop footpoints, reflecting the time variations of the
vertical extent of the energy deposition layer. Our result shows that
the fast time variations of the Hα emission of the flaring kernels
can be explained by momentary changes of the deposited energy flux
and the variations of the penetration depths of the NTEs.

---------------------------------------------------------
Title: Optical measurements of the mirrors and of the interferential
filter of the Metis coronagraph on Solar Orbiter
Authors: Sandri, P.; Sarra, P.; Radaelli, P.; Morea, D.; Melich,
R.; Berlicki, A.; Antonucci, E.; Castronuovo, M. M.; Fineschi, S.;
Naletto, G.; Nicolini, G.; Romoli, M.
2017SPIE10397E..16S Altcode:
The paper describes the wavefront error measurements of the concave
ellipsoidal mirrors M1 and M2, of the concave spherical mirror M0 and
of the flat interferential filter IF of the Metis coronagraph. Metis is
an inverted occultation coronagraph on board of the ESA Solar Orbiter
mission providing a broad-band imaging of the full corona in linearly
polarized visible-light (580 - 640 nm) and a narrow-band imaging of
the full corona in the ultraviolet Lyman α (121.6 nm). Metis will
observe the solar outer atmosphere from a close distance to the Sun
as 0.28 A.U. and from up to 35deg out-of-ecliptic. The measurements of
wavefront error of the mirrors and of the interferential filter of Metis
have been performed in a ISO5 clean room both at component level and at
assembly level minimizing, during the integration, the stress introduced
by the mechanical hardware. The wavefront error measurements have been
performed with a digital interferometer for mirrors M0, M1 and M2 and
with a Shack-Hartmann wavefront sensor for the interferential filter.

---------------------------------------------------------
Title: Structure and Dynamics of Cool Flare Loops Observed by the
Interface Region Imaging Spectrograph
Authors: Mikuła, K.; Heinzel, P.; Liu, W.; Berlicki, A.
2017ApJ...845...30M Altcode:
Flare loops were well observed with the Interface Region Imaging
Spectrograph (IRIS) during the gradual phase of two solar flares
on 2014 March 29 and 2015 June 22. Cool flare loops are visible in
various spectral lines formed at chromospheric and transition-region
temperatures and exhibit large downflows which correspond to the
standard scenario. The principal aim of this work is to analyze
the structure and dynamics of cool flare loops observed in Mg II
lines. Synthetic profiles of the Mg II h line are computed using the
classical cloud model and assuming a uniform background intensity. In
this paper, we study novel IRIS NUV observations of such loops in Mg II
h and k lines and also show the behavior of hotter lines detected in
the FUV channel. We obtained the spatial evolution of the velocities:
near the loop top, the flow velocities are small and they are increasing
toward the loop legs. Moreover, from slit-jaw image (SJI) movies, we
observe some plasma upflows into the loops, which are also detectable
in Mg II spectra. The brightness of the loops systematically decreases
with increasing flow velocity, and we ascribe this to the effect of
Doppler dimming, which works for Mg II lines. Emission profiles of Mg
II were found to be extremely broad, and we explain this through the
large unresolved non-thermal motions.

---------------------------------------------------------
Title: Recruiting flare hunters for citizen science
Authors: Fletcher, Lyndsay; Berlicki, Arkadiusz; Awasthi, Arun Kumar;
Gronkiewicz, Dominik
2016A&G....57f6.21F Altcode:
Lyndsay Fletcher, Arkadiusz Berlicki, Arun Kumar Awasthi and Dominik
Gronkiewicz describe how they established F-HUNTERS, a pro-am solar
flare observing campaign.

---------------------------------------------------------
Title: Height formation of bright points observed by IRIS in Mg II
line wings during flux emergence
Authors: Grubecka, M.; Schmieder, B.; Berlicki, A.; Heinzel, P.;
Dalmasse, K.; Mein, P.
2016A&A...593A..32G Altcode:
Context. A flux emergence in the active region AR 111850 was observed
on September 24, 2013 with the Interface Region Imaging Spectrograph
(IRIS). Many bright points are associated with the new emerging flux
and show enhancement brightening in the UV spectra. Aims:
The aim of this work is to compute the altitude formation of the
compact bright points (CBs) observed in Mg II lines in the context
of searching Ellerman bombs (EBs). Methods: IRIS provided two
large dense rasters of spectra in Mg II h and k lines, Mg II triplet,
C II and Si IV lines covering all the active region and slit jaws in
the two bandpasses (1400 Å and 2796 Å) starting at 11:44 UT and
15:39 UT, and lasting 20 min each. Synthetic profiles of Mg II and
Hα lines are computed with non-local thermodynamic equlibrium (NLTE)
radiative transfer treatment in 1D solar atmosphere model including
a hotspot region defined by three parameters: temperature, altitude,
and width. Results: Within the two IRIS rasters, 74 CBs are
detected in the far wings of the Mg II lines (at +/-1 Å and 3.5
Å). Around 10% of CBs have a signature in Si IV and CII. NLTE models
with a hotspot located in the low atmosphere were found to fit a sample
of Mg II profiles in CBs. The Hα profiles computed with these Mg II
CB models are consistent with typical EB profiles observed from ground
based telescopes e.g. THEMIS. A 2D NLTE modelling of fibrils (canopy)
demonstrates that the Mg II line centres can be significantly affected
but not the peaks and the wings of Mg II lines. Conclusions:
We conclude that the bright points observed in Mg II lines can be
formed in an extended domain of altitudes in the photosphere and/or
the chromosphere (400 to 750 km). Our results are consistent with the
theory of heating by Joule dissipation in the atmosphere produced by
magnetic field reconnection during flux emergence.

---------------------------------------------------------
Title: Flares In Time-Domain Surveys
Authors: Kowalski, Adam; Hawley, Suzanne; Davenport, James; Berlicki,
Arkadiusz; Cauzzi, Gianna; Fletcher, Lyndsay; Heinzel, Petr; Notsu,
Yuta; Loyd, Parke; Martinez Oliveros, Juan Carlos; Pugh, Chloe;
Schmidt, Sarah Jane; Karmakar, Subhajeet; Pye, John; Flaccomio, Ettore
2016csss.confE.126K Altcode:
Proceedings for the splinter session "Flares in Time-Domain Surveys"
convened at Cool Stars 19 on June 07, 2016 in Uppsala, Sweden. Contains
a two page summary of the splinter session, links to YouTube talks,
and a PDF copy of the slides from the presenters.

---------------------------------------------------------
Title: Astronomy popularization at the University of Wrocław
Authors: Preś, Paweł; Cader-Sroka, Barbara; Berlicki, Arkadiusz
2016pas..conf..267P Altcode:
Science popularization found many expressions in the history of the
Astronomical Institute of the University of Wrocław. The long-lasting
is the tradition of popular astronomy lectures. Occasional celestial
events are the base of public observations. Since 1998 the Institute
boldly participates in the Lower-Silesian Science Festival. The rising
public interest in astronomy encouraged us to establish ”Planetarium”
laboratory in 2008. Together with the Astronomical Institute of the
Academy of Sciences of the Czech Republic we established in 2009
the very first trans-border dark-sky park in the location of Izera
Mountains, where since then the public can benefit from excellent
observational conditions and the astronomers' support.

---------------------------------------------------------
Title: Observations and modeling of the ultraviolet emission of
solar flares
Authors: Mikuła, Katarzyna; Berlicki, Arkadiusz; Heinzel, Petr
2016IAUS..320...57M Altcode:
In this paper we present the method of using far UV spectra of
the flare observed by Interface Region Imaging Spectrograph (IRIS)
for determination of the contribution of the continuum emission to
the total UV radiation observed e.g. by SDO in 1600 Å channel. In
our method the Si IV (1402.77 Å) line observed by IRIS is used as a
proxy of C IV line emission contained in SDO/AIA UV images. Determined
intensity of the flare continuum emission can be used to study the
physics of the flare heated chromosphere and for better understanding
of the emission mechanisms.

---------------------------------------------------------
Title: White-light continuum emission from a solar flare and plage
Authors: Berlicki, Arkadiusz; Awasthi, Arun Kumar; Heinzel, Petr;
Sobotka, Michal
2016IAUS..320..268B Altcode: 2016arXiv160404186B
Observations of flare emissions in the optical continuum are very
rare. Therefore, the analysis of such observations is useful and
may contribute to our understanding of the flaring chromosphere and
photosphere. We study the white light continuum emission observed
during the X6.9 flare. This emission comes not only from the flare
ribbons but also form the nearby plage area. The main aim of this work
is to disentangle the flare and plage (facula) emission. We analyzed
the spatial, spectral and temporal evolution of the flare and plage
properties by analyzing multi-wavelength observations. We study
the morphological correlation of the white-light continuum emission
observed with different instruments. We found that some active region
areas which produce the continuum emission correspond rather to plages
than to the flare kernels. We showed that in some cases the continuum
emission from the WL flare kernels is very similar to the continuum
emission of faculae.

---------------------------------------------------------
Title: White-light continuum emission from solar flare and plages:
observations and modeling
Authors: Berlicki, Arkadiusz; Awasthi, Arun Kumar; Heinzel, Petr
2015IAUGA..2256469B Altcode:
Observations of flares in optical continuum emission are very
rare. Therefore, the analysis of such observations is very useful and
may contribute to our understanding of the flaring chromosphere. We
study the white-light continuum emission observed during the X6.9
flare observed on August 09, 2011. This emission comes not only from
the flare ribbons but also form the nearby plage area observed within
the active region. The main aim of this work is to disentangle the
flare and plage emission and to understand the physical mechanisms
responsible for the production of white-light continuum.There are two
main mechanisms which can be responsible for the optical continuum
emission of the solar atmosphere: enhanced photospheric H- continuum
due to the temperature increase below the temperature minimum region,
or hydrogen recombination continua (Balmer, Paschen) formed in solar
chromosphere. In our work we analyse the physical conditions in solar
active atmosphere in order to obtain the contribution from these two
mechanisms to the whole continuum emission of the flare and plage.We
analyzed the spatial, spectral and temporal evolution study of the
flare and plage parameters by analyzing multi-wavelength observations
obtained from ground and space based solar observatories. We study
the morphological correlation of the white-light continuum emission
observed with different instruments. Moreover, we also explore the
non-thermal electron beam properties by forward fitting the observed
X-ray spectra.The unique opportunity of an intense X6.9 flare occurrence
close to the limb enabled us to explore the origin of white-light
continuum with better visibility. The analysis of multi-wavelength
data revealed the origin of this emission from the foot-points of the
loops. Spatial association of HXR foot-points synthesized from RHESSI
observations confirmed this finding. In addition, we found a good
temporal correlation of hard (&gt;30 keV) X-ray with the white-light
emission. However, some active region areas which produce the continuum
emission correspond rather to plages than to the flare kernels.

---------------------------------------------------------
Title: Multi-wavelength diagnostics and modelling of the emission
during a B6.4 flare of August 20, 2005
Authors: Awasthi, Arun Kumar; Berlicki, Arkadiusz; Rudawy, Powel;
Heinzel, Petr
2015IAUGA..2256580A Altcode:
We study the temporal, spatial and spectral evolution of
multi-wavelength emission observed during a B6.4 flare occurred
on August 20, 2005 with the motivation to outline the thermal and
non-thermal processes during the precursor and gradual phase of the
flare. Precursor phase is designated as the gradual enhancement of
soft X-ray emission prior to onset of the impulsive phase. Observations
from several space and ground based observatories viz. RHESSI, TRACE,
GONG, SoHO/EIT and NoRP are included in this study. Temporal evolution
of X-ray emission does not show the presence of hard X-rays (&gt;12
keV) emission during the precursor phase of the flare. We synthesized
X-ray images in 6-12 keV from RHESSI observations, which show several
discrete sources during the precursor phase. Following to this, one
of these sources pronounced during the main phase of the flare. We
carry out in-depth analysis of chromospheric response in various
phases of the flare employing high temporal cadence images of the Sun
in Hα line centre as well as wings obtained from the Multi-channel
Subtractive Double Pass Spectrograph (MSDP) at the Bialkow Observatory
of the University of Wroclaw, Poland. Our analysis of Hα images
during the main phase of the flare suggests localized emission in
the form of kernels. On the contrary, we note extended and diffused
source morphology of emitting region during the precursor phase of
the flare. We also study various kinematic properties of different
structures visible in the Hα images in the line centre as well as
wings. In addition, the correlation of the relative timing of X-ray
and Hα emission profile is performed to estimate the delay in the
chromospheric response during different phases of flare. Further, we
employ thermal plasma parameters estimated during the precursor and
gradual phase to model the associated Hα emission. For the modeling we
employ NLTE numerical codes modified for flare conditions. The modeled
and observed flare emission parameters are then compared. Finally,
we propose a unified schematic scenario for the trigger and energy
release during this low-intensity class flare.

---------------------------------------------------------
Title: Observations and modeling of the ultraviolet emission of
solar flares
Authors: Berlicki, Arkadiusz; Heinzel, Petr; Mikula, Katarzyna
2015IAUGA..2257337B Altcode:
It is well known that during solar flares the heated chromospheric
plasma emits the ultraviolet (UV) radiation in spectral lines
and continua. UV space telescopes (e.g. TRACE, Solar Dynamic
Observatory/Atmospheric Imaging Assembly - SDO/AIA) provide images
of solar flares where the complicated fine structure of the flaring
atmosphere is well visible. However, these broadband images contain
the mixture of line and continuum UV emission and it is not possible
to disentangle between these two contributions. E.g. solar flare
brightening observed in SDO/AIA 160 nm channel can be visible both due
to the strong line emission in C IV 154.8 nm or due to the continuum
increase. Spectral lines and continua are formed in plasma of different
temperature and location. Therefore, in order to obtain the parameters
of plasma we should know quantitatively the contribution from lines and
continua.Such analysis would be possible using the UV spectrograph,
where we can see the intensity of lines and continua separately. For
example Interface Region Imaging Spectrograph (IRIS) provides such
spectra of flares, where the enhanced lines and continuum is visible
both in NUV (near UV) and FUV (far UV) channels.In our work we used
IRIS flare observations in FUV channel to determine the intensity of
spectral lines, including Si IV 139.4 nm line. Then, using CHIANTI
procedures and the observed intensities of some FUV lines we computed
the synthetic UV spectrum for given flare model. IRIS spectrum does not
include C IV line, which contaminates the SDO/AIA images, but this line
can be calculated in the theoretical CHIANTI spectrum. In this way, we
can subtract the C IV (and other lines) emission from SDO/AIA images and
obtain the pure UV continuum intensity. Finally, the obtained continuum
emission can used to study the physics of heated chromosphere of flares.

---------------------------------------------------------
Title: Dark Sky Protection and Education - Izera Dark Sky Park
Authors: Berlicki, Arkadiusz; Kolomanski, Sylwester; Mrozek, Tomasz;
Zakowicz, Grzegorz
2015IAUGA..2257138B Altcode:
Darkness of the night sky is a natural component of our environment and
should be protected against negative effects of human activities. The
night darkness is necessary for balanced life of plants, animals
and people. Unfortunately, development of human civilization and
technology has led to the substantial increase of the night-sky
brightness and to situation where nights are no more dark in many areas
of the World. This phenomenon is called "light pollution" and it can
be rank among such problems as chemical pollution of air, water and
soil. Besides the environment, the light pollution can also affect
e.g. the scientific activities of astronomers - many observatories
built in the past began to be located within the glow of city lights
making the night observations difficult, or even impossible.In order to
protect the natural darkness of nights many so-called "dark sky parks"
were established, where the darkness is preserved, similar to typical
nature reserves. The role of these parks is not only conservation
but also education, supporting to make society aware of how serious
the problem of the light pollution is.History of the dark sky areas
in Europe began on November 4, 2009 in Jizerka - a small village
situated in the Izera Mountains, when Izera Dark Sky Park (IDSP)
was established - it was the first transboundary dark sky park in
the World. The idea of establishing that dark sky park in the Izera
Mountains originated from a need to give to the society in Poland and
Czech Republic the knowledge about the light pollution. Izera Dark
Sky Park is a part of the astro-tourism project "Astro Izery" that
combines tourist attraction of Izera Valley and astronomical education
under the wonderful starry Izera sky. Besides the IDSP, the project
Astro Izery consists of the set of simple astronomical instruments
(gnomon, sundial), natural educational trail "Solar System Model",
and astronomical events for the public. In addition, twice a year we
organize a 3-4 days "Astronomy Workshop for Schools", where teachers
and astronomers from Astronomical Institute (University of Wroclaw)
educate the young generations in the field of astronomy and other
physical sciences.

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Title: On the Visibility of Prominence Fine Structures at Radio
Millimeter Wavelengths
Authors: Heinzel, P.; Berlicki, A.; Bárta, M.; Karlický, M.;
Rudawy, P.
2015SoPh..290.1981H Altcode: 2015SoPh..tmp...87H
Prominence temperatures have so far mainly been determined by analyzing
spectral line shapes, which is difficult when the spectral lines are
optically thick. The radio spectra in the millimeter range offer
a unique possibility to measure the kinetic temperature. However,
studies in the past used data with insufficient spatial resolution
to resolve the prominence fine structures. The aim of this article
is to predict the visibility of prominence fine structures in the
submillimeter/millimeter (SMM) domain, to estimate their brightness
temperatures at various wavelengths, and to demonstrate the feasibility
and usefulness of future high-resolution radio observations of
solar prominences with ALMA (Atacama Large Millimeter-submillimeter
Array). Our novel approach is the conversion of Hα coronagraphic images
into microwave spectral images. We show that the spatial variations
of the prominence brightness both in the Hα line and in the SMM
domain predominantly depend on the line-of-sight emission measure of
the cool plasma, which we derive from the integrated intensities of
the observed Hα line. This relation also offers a new possibility to
determine the SMM optical thickness from simultaneous Hα observations
with high resolution. We also describe how we determine the prominence
kinetic temperature from SMM spectral images. Finally, we apply the
ALMA image-processing software Common Astronomy Software Applications
(CASA) to our simulated images to assess what ALMA would detect at a
resolution level that is similar to the coronagraphic Hα images used
in this study. Our results can thus help in preparations of first
ALMA prominence observations in the frame of science and technical
verification tests.

---------------------------------------------------------
Title: Observations and NLTE modeling of Ellerman bombs
Authors: Berlicki, A.; Heinzel, P.
2014A&A...567A.110B Altcode: 2014arXiv1406.5702B
Context. Ellerman bombs (EBs) are short-lived, compact, and spatially
well localized emission structures that are observed well in the wings
of the hydrogen Hα line. EBs are also observed in the chromospheric
CaII lines and in UV continua as bright points located within active
regions. Hα line profiles of EBs show a deep absorption at the line
center and enhanced emission in the line wings with maxima around
±1 Å from the line center. Similar shapes of the line profiles are
observed for the CaII IR line at 8542 Å. In CaII H and K lines the
emission peaks are much stronger, and EBs emission is also enhanced
in the line center. Aims: It is generally accepted that
EBs may be considered as compact microflares located in lower solar
atmosphere that contribute to the heating of these low-lying regions,
close to the temperature minimum of the atmosphere. However, it is
still not clear where exactly the emission of EBs is formed in the
solar atmosphere. High-resolution spectrophotometric observations
of EBs were used for determining of their physical parameters and
construction of semi-empirical models. Obtained models allow us to
determine the position of EBs in the solar atmosphere, as well as
the vertical structure of the activated EB atmosphere Methods:
In our analysis we used observations of EBs obtained in the Hα and
CaII H lines with the Dutch Open Telescope (DOT). These one-hour
long simultaneous sequences obtained with high temporal and spatial
resolution were used to determine the line emissions. To analyze them,
we used NLTE numerical codes for the construction of grids of 243
semi-empirical models simulating EBs structures. In this way, the
observed emission could be compared with the synthetic line spectra
calculated for all such models. Results: For a specific model
we found reasonable agreement between the observed and theoretical
emission and thus we consider such model as a good approximation to EBs
atmospheres. This model is characterized by an enhanced temperature in
the lower chromosphere and can be considered as a compact structure (hot
spot), which is responsible for the emission observed in the wings of
chromospheric lines, in particular in the Hα and CaII H lines. 
Conclusions: For the first time the set of two lines Hα and CaII H was
used to construct semi-empirical models of EBs. Our analysis shows that
EBs can be described by a "hot spot" model, with the temperature and/or
density increase through a few hundred km atmospheric structure. We
confirmed that EBs are located close to the temperature minimum or
in the lower chromosphere. Two spectral features (lines in our case),
observed simultaneously, significantly strengthen the constraints on
a realistic model.

---------------------------------------------------------
Title: F-CHROMA.Flare Chromospheres: Observations, Models and Archives
Authors: Cauzzi, Gianna; Fletcher, Lyndsay; Mathioudakis, Mihalis;
Carlsson, Mats; Heinzel, Petr; Berlicki, Arek; Zuccarello, Francesca
2014AAS...22412339C Altcode:
F-CHROMA is a collaborative project newly funded under the EU-Framework
Programme 7 "FP7-SPACE-2013-1", involving seven different European
research Institutes and Universities. The goal of F-CHROMA is to
substantially advance our understanding of the physics of energy
dissipation and radiation in the flaring solar atmosphere, with a
particular focus on the flares' chromosphere. A major outcome of the
F-CHROMA project will be the creation of an archive of chromospheric
flare observations and models to be made available to the community
for further research.In this poster we describe the structure and
milestones of the project, the different activities planned, as well
as early results. Emphasis will be given to the dissemination efforts
of the project to make results of these activities available to and
usable by the community.

---------------------------------------------------------
Title: Multi Element Telescope for Imaging and Spectroscopy (METIS)
coronagraph for the Solar Orbiter mission
Authors: Antonucci, Ester; Fineschi, Silvano; Naletto, Giampiero;
Romoli, Marco; Spadaro, Daniele; Nicolini, Gianalfredo; Nicolosi,
Piergiorgio; Abbo, Lucia; Andretta, Vincenzo; Bemporad, Alessandro;
Auchère, Frédéric; Berlicki, Arkadiusz; Bruno, Roberto; Capobianco,
Gerardo; Ciaravella, Angela; Crescenzio, Giuseppe; Da Deppo, Vania;
D'Amicis, Raffaella; Focardi, Mauro; Frassetto, Fabio; Heinzel,
Peter; Lamy, Philippe L.; Landini, Federico; Massone, Giuseppe;
Malvezzi, Marco A.; Moses, J. Dan; Pancrazzi, Maurizio; Pelizzo,
Maria-Guglielmina; Poletto, Luca; Schühle, Udo H.; Solanki, Sami K.;
Telloni, Daniele; Teriaca, Luca; Uslenghi, Michela
2012SPIE.8443E..09A Altcode:
METIS, the “Multi Element Telescope for Imaging and Spectroscopy”,
is a coronagraph selected by the European Space Agency to be part of
the payload of the Solar Orbiter mission to be launched in 2017. The
unique profile of this mission will allow 1) a close approach to the
Sun (up to 0.28 A.U.) thus leading to a significant improvement in
spatial resolution; 2) quasi co-rotation with the Sun, resulting in
observations that nearly freeze for several days the large-scale outer
corona in the plane of the sky and 3) unprecedented out-of-ecliptic
view of the solar corona. This paper describes the experiment concept
and the observational tools required to achieve the science drivers
of METIS. METIS will be capable of obtaining for the first time: •
simultaneous imaging of the full corona in polarized visible-light
(590-650 nm) and narrow-band ultraviolet HI Lyman α (121.6 nm); •
monochromatic imaging of the full corona in the extreme ultraviolet
He II Lyman α (30.4 nm); • spectrographic observations of the HI
and He II Ly α in corona. These measurements will allow a complete
characterization of the three most important plasma components of
the corona and the solar wind, that is, electrons, hydrogen, and
helium. This presentation gives an overview of the METIS imaging and
spectroscopic observational capabilities to carry out such measurements.

---------------------------------------------------------
Title: METIS: a novel coronagraph design for the Solar Orbiter mission
Authors: Fineschi, Silvano; Antonucci, Ester; Naletto, Giampiero;
Romoli, Marco; Spadaro, Daniele; Nicolini, Gianalfredo; Abbo, Lucia;
Andretta, Vincenzo; Bemporad, Alessandro; Berlicki, Arkadiusz;
Capobianco, Gerardo; Crescenzio, Giuseppe; Da Deppo, Vania; Focardi,
Mauro; Landini, Federico; Massone, Giuseppe; Malvezzi, Marco A.;
Moses, J. Dan; Nicolosi, Piergiorgio; Pancrazzi, Maurizio; Pelizzo,
Maria-Guglielmina; Poletto, Luca; Schühle, Udo H.; Solanki, Sami K.;
Telloni, Daniele; Teriaca, Luca; Uslenghi, Michela
2012SPIE.8443E..3HF Altcode:
METIS (Multi Element Telescope for Imaging and Spectroscopy) METIS,
the “Multi Element Telescope for Imaging and Spectroscopy”,
is a coronagraph selected by the European Space Agency to be part
of the payload of the Solar Orbiter mission to be launched in
2017. The mission profile will bring the Solar Orbiter spacecraft
as close to the Sun as 0.3 A.U., and up to 35° out-of-ecliptic
providing a unique platform for helio-synchronous observations of
the Sun and its polar regions. METIS coronagraph is designed for
multi-wavelength imaging and spectroscopy of the solar corona. This
presentation gives an overview of the innovative design elements of
the METIS coronagraph. These elements include: i) multi-wavelength,
reflecting Gregorian-telescope; ii) multilayer coating optimized for
the extreme UV (30.4 nm, HeII Lyman-α) with a reflecting cap-layer
for the UV (121.6 nm, HI Lyman-α) and visible-light (590-650); iii)
inverse external-occulter scheme for reduced thermal load at spacecraft
peri-helion; iv) EUV/UV spectrograph using the telescope primary mirror
to feed a 1st and 4th-order spherical varied
line-spaced (SVLS) grating placed on a section of the secondary mirror;
v) liquid crystals electro-optic polarimeter for observations of the
visible-light K-corona. The expected performances are also presented.

---------------------------------------------------------
Title: Velocity Vector, Ionization Degree, and Temperature of
Prominence Fine Structures Observed by Hinode/SOT
Authors: Schmieder, B.; Mein, P.; Chandra, R.; Molodij, G.; Heinzel,
P.; Berlicki, A.; Schwartz, P.; Fárník, F.; Labrosse, N.; Anzer,
U.; Watanabe, T.
2012ASPC..454..107S Altcode:
Prominences have been successfully observed by Hinode in April 2007
exhibiting a strong dynamics of their fine structures. The dynamics
of a prominence is a challenge to understand the formation of cool
prominence plasma embedded in the hot corona. Combining simultaneous
observations obtained in Hα with Hinode/SOT and the MSDP spectrograph
operating at the Meudon solar tower, velocity vectors have been
derived. The Doppler-shifts of bright threads are of the same order
as the velocities measured perpendicular to the line of sight. This
suggests that the vertical structures of the prominence could be a pile
up of dips in magnetic field lines viewed in 3D. Using Hα, Hinode/XRT
and TRACE data, the hydrogen ionization degree has been determined to
be 0.5-0.8, and the optical thickness in Hα between 0.2 and 1.3. The
Extreme Ultraviolet Imaging Spectrometer (EIS) on Hinode produced images
of the prominence in 11 selected lines with formation temperatures
between log(T) = 4.7 and log(T) = 6.1. We comment on the absorption,
emissivity blocking and emission involved for interpreting the different
structures of the prominence in terms of the temperature and density.

---------------------------------------------------------
Title: 2D radiative-magnetohydrostatic model of a prominence observed
by Hinode, SoHO/SUMER and Meudon/MSDP
Authors: Berlicki, A.; Gunar, S.; Heinzel, P.; Schmieder, B.;
Schwartz, P.
2011A&A...530A.143B Altcode:
 Aims: Prominences observed by Hinode show very dynamical and
intriguing structures. To understand the mechanisms that are responsible
for these moving structures, it is important to know the physical
conditions that prevail in fine-structure threads. In the present work
we analyse a quiescent prominence with fine structures, which exhibits
dynamic behaviour, which was observed in the hydrogen Hα line with
Hinode/SOT, Meudon/MSDP and Ondřejov/HSFA2, and simultaneously in
hydrogen Lyman lines with SoHO/SUMER during a coordinated campaign. We
derive the fine-structure physical parameters of this prominence and
also address the questions of the role of the magnetic dips and of
the interpretation of the flows. Methods: We calibrate the
SoHO/SUMER and Meudon/MSDP data and obtain the line profiles of the
hydrogen Lyman series (Lβ to L6), the Ciii (977.03 Å) and Svi (933.40
Å), and Hα along the slit of SoHO/SUMER that crosses the Hinode/SOT
prominence. We employ a complex 2D radiation-magnetohydrostatic (RMHS)
modelling technique to properly interpret the observed spectral
lines and derive the physical parameters of interest. The model
was constrained not only with integrated intensities of the lines,
but also with the hydrogen line profiles. Results: The slit
of SoHO/SUMER is crossing different prominence structures: threads
and dark bubbles. Comparing the observed integrated intensities, the
depressions of Hα bubbles are clearly identified in the Lyman, Ciii,
and Svi lines. To fit the observations, we propose a new 2D model
with the following parameters: T = 8000 K, pcen = 0.035
dyn cm-2, B = 5 Gauss, ne = 1010
cm-3, 40 threads each 1000 km wide, plasma β is 3.5 ×
10-2. Conclusions: The analysis of Ciii and Svi
emission in dark Hα bubbles allows us to conclude that there is no
excess of a hotter plasma in these bubbles. The new 2D model allows us
to diagnose the orientation of the magnetic field versus the LOS. The
40 threads are integrated along the LOS. We demonstrate that integrated
intensities alone are not sufficient to derive the realistic physical
parameters of the prominence. The profiles of the Lyman lines and also
those of the Hα line are necessary to constrain 2D RMHS models. The
magnetic field in threads is horizontal, perpendicular to the LOS,
and in the form of shallow dips. With this geometry the dynamics of
fine structures in prominences could be interpreted by a shrinkage of
the quasi-horizontal magnetic field lines and apparently is not caused
by the quasi-vertical bulk flows of the plasma, as Hinode/SOT movies
seemingly suggest.

---------------------------------------------------------
Title: Multi-wavelength analysis of Ellerman Bomb Light Curves
Authors: Herlender, M.; Berlicki, A.
2011CEAB...35..181H Altcode:
We present the results of a multi-wavelength photometric analysis
of Ellerman Bomb (EB) observations obtained from the Dutch Open
Telescope. In our data we have found 6 EBs located in the super-penumbra
of the main spot in the active region NOAA 10781. We present light
curves of EB observed in the Hα line centre and wing +0.7 Å, in the
Ca II H line centre and wing~+2.35 Å, in the G-band and in the TRACE
1600 Å filter. We have shown that EBs were visible in the G-band and
moreover, there was a good correlation between the light curves in
the G-band and in the Hα line wings. We also found quasi-periodic
oscillations of EBs brightness in the G-band, CaII H line and TRACE
1600 Å filter.

---------------------------------------------------------
Title: Solar Flares and the Chromosphere
Authors: Fletcher, L.; Turkmani, R.; Hudson, H. S.; Hawley, S. L.;
Kowalski, A.; Berlicki, A.; Heinzel, P.
2010arXiv1011.4650F Altcode:
A white paper prepared for the Space Studies Board, National Academy
of Sciences (USA), for its Decadal Survey of Solar and Space Physics
(Heliophysics), reviewing and encouraging studies of flare physics in
the chromosphere.

---------------------------------------------------------
Title: Solar Flares and the Chromosphere: A white paper for the
Decadal Survey
Authors: Hudson, H. S.; Fletcher, L.; Turkmani, R.; Hawley, S. L.;
Kowalski, A. F.; Berlicki, A.; Heinzel, P.
2010helio2010....1H Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Flare Energy Build-Up in a Decaying Active Region Near a
Coronal Hole
Authors: Su, Yingna; van Ballegooijen, Adriaan; Schmieder, Brigitte;
Berlicki, Arkadiusz; Guo, Yang; Golub, Leon; Huang, Guangli
2010shin.confE.131S Altcode:
A B1.7 two-ribbon flare occurred in a highly non-potential decaying
active region near a coronal hole at 10:00 UT on May 17, 2008. This
flare is large in the sense that it involves the entire region, and
it is associated with both a filament eruption and a CME. We present
multi-wavelength observations from EUV (TRACE, STEREO/EUVI), X-rays
(Hinode/XRT), and H-alpha (THEMIS, BBSO) prior to, during and after
the flare. Prior to the flare, the region contained two filaments. The
long J-shaped sheared loops corresponding to the southern filament
were evolved from two short loop systems, which happened around 22:00
UT after a filament eruption on May 16. Formation of highly sheared
loops in the south eastern part of the region was observed by STEREO
8 hours before the flare. We also perform non-linear force free field
(NLFFF) modeling for the region at two times prior to the flare, using
the flux rope insertion method. The models include the non-force-free
effect of magnetic buoyancy in the photosphere. The best-fit NLFFF
models show good fit to observations both in the corona (X-ray and EUV
loops) and chromosphere (H-alpha filament). We find that the horizontal
fields in the photosphere are relatively insensitive to the present of
flux ropes in the corona. The axial flux of the flux rope in the NLFFF
model on May 17 is twice that on May 16, and the model on May 17 is only
marginally stable. We also find that the quasi-circular flare ribbons
are associated with the separatrix between open and closed fields. This
observation and NLFFF modeling suggest that this flare may be triggered
by the reconnection at the null point on the separatrix surface.

---------------------------------------------------------
Title: Velocity vectors of a quiescent prominence observed by
Hinode/SOT and the MSDP (Meudon)
Authors: Schmieder, B.; Chandra, R.; Berlicki, A.; Mein, P.
2010A&A...514A..68S Altcode: 2009arXiv0911.5091S
Context. The dynamics of prominence fine structures present a
challenge to our understanding of the formation of cool plasma
prominence embedded in the hot corona. Aims: Observations
performed by the high resolution Hinode/SOT telescope allow us to
compute velocities perpendicular to the line-of-sight or transverse
velocities. Combining simultaneous observations obtained in Hα with
Hinode/SOT and the MSDP spectrograph operating in the Meudon solar
tower, we derive the velocity vectors of a quiescent prominence. Methods: The velocities perpendicular to the line-of-sight are
measured using a time-slice technique and the Doppler shifts velocity
using the bisector method. Results: The Doppler shifts of
bright threads derived from the MSDP show counterstreaming of the
order of 5 km s-1 in the prominence and reaching 15 km
s-1 at the edges of the prominence. Even though they are
minimum values because of seeing effects, they are of the same order
as the transverse velocities. Conclusions: These measurements
are very important because they suggest that the vertical structures
detected by SOT may not be true vertical magnetic structures in the sky
plane. The vertical structures could be a pile up of dips in more or
less horizontal magnetic field lines in a 3D perspective, as proposed
by many MHD modelers. In our analysis, we also calibrate the Hinode
Hα data using MSDP observations obtained simultaneously. A movie
is available in electronic form at http://www.aanda.org

---------------------------------------------------------
Title: Counterstreaming in quiescent prominences observed by
Hinode/SOT and Meudon/MSDP
Authors: Schmieder, Brigitte; Chandra, Ramesh; Berlicki, Arkadiusz;
Mein, Pierre
2010cosp...38.2943S Altcode: 2010cosp.meet.2943S
Prominences have been successfully observed by Hinode in April 2007
exhibiting a strong dy-namics of their fine structures. The dynamics
of a prominence is a challenge to understand the formation of cool
prominence plasma embedded in the hot corona. Combining simultaneous
observations obtained in Hα with Hinode/SOT and the MSDP spectrograph
operating at the Meudon solar tower, velocity vectors have been
derived. The Doppler-shifts of bright threads are of the same order
as the transverse velocities measured perpendicularly to the line of
sight. Counterstreamings are detected at the top of the prominence. The
vertical structures of the prominence could be a pile up of dips in
magnetic field lines viewed in 3D

---------------------------------------------------------
Title: Relations between theoretical and observational plasma
parameters and the radiation of the prominence
Authors: Berlicki, Arkadiusz; Schwartz, Pavol; Schmieder, Brigitte;
Heinzel, Petr; Gunar, Stanislav
2010cosp...38.2945B Altcode: 2010cosp.meet.2945B
On April 26, 2007 the quiescent prominence was observed during the
coordinated campaign of prominence studies icluding SOT, XRT, and
EIS on Hinode, MDI, EIT, SUMER, and CDS on SOHO, TRACE, and several
ground-based observatories. This was the first Hinode-SUMER ob-serving
campaign. In this analysis we use the data obtained with Hinode/SOT,
SOHO/SUMER and Multichannel Spectrograph MSDP (Meudon, France). The
SUMER instrument provide us the UV spectra of the prominence in several
spectral lines along the 120 arcsec slit crossing the prominence. We
used the following lines: Lβ, Lγ, Lδ, L , C III and S VI. Using
these spectra we calculated the integrated intensities along the slit
for all these lines. We also calculated the integrated intensity of
the Hα line from the spectroscopic ground-based MSDP observations
for the same parts of the prominence observed at the same time. These
intensities were used to calibrate the Hinode/SOT data. Next, we
analyzed the relations between different observed intensities in these
lines and compared them with the values obtained from the theoretical
simulations. We analyzed the correlations between observations and
theoretical modeling and as a results we estimated the different
physical parameters of the prominence plasma.

---------------------------------------------------------
Title: Photometric analysis of Ellerman bombs .
Authors: Berlicki, A.; Heinzel, P.; Avrett, E. H.
2010MmSAI..81..646B Altcode:
Observations of Ellerman bombs (EBs) show them as short-lived,
compact, and spatially localized emissions that are well observable
in the wings of the Halpha hydrogen line. The Halpha line profiles
of EBs are characterized by deep absorption at the line center and
enhanced emission in the wings with maximum around ± 1 Å from the
line center, fading beyond ± 5 Å. EBs may also be observed in the
chromospheric Ca II lines and in the UV as bright points often located
within active regions. Previous work suggests that EBs may be considered
as micro-flares and may contribute significantly to the heating of the
lower chromosphere in newly emerging magnetic flux regions. However,
it is still not clear at what height in the solar atmosphere the
emission of EBs originates. In our analysis we used observations of
EBs obtained in the Halpha line with the Dutch Open Telescope (DOT)
and in the UV range with the TRACE 1600 Å channel. These one-hour
long simultaneous sequences obtained with high temporal and spatial
resolution were used to analyze the relation between the emission in
the Halpha line and at 1600 Å. The observations show fast variations of
EB emission in both channels. Comparison between the observed emission
in Halpha and at 1600 Å and theoretical calculations allowed us to
draw conclusions about the vertical structure of EBs.

---------------------------------------------------------
Title: Spectrophotometric Analysis of an Ellerman bomb
Authors: Herlender, M.; Berlicki, A.
2010CEAB...34...65H Altcode:
In this paper we present results of spectrophotometric analysis of an
Ellerman bomb (EB), which was observed on June 5, 2003 in the active
region NOAA 10735. The observations were made in the Hα line using the
spectro-imager MSDP mode of the Large Coronograph of The Observatory
of Astronomical Institute of the University of Wrocław. The observed
EB was located near the foot-point of an arch filament system, and was
observed for three hours showing five individual peaks of brightness. We
present the light curve at five wavelengths from the Hα line centre
to Hα+0.8 Å with a step of 0.2 Å. We also present profiles of the
Hα line of the EB at different stages of their evolution. At those
profiles one can see that, there is characteristic excess of emission
in the Hα line wings. In addition, when the line wings are brighter,
the intensity of the Hα line centre is weaker.

---------------------------------------------------------
Title: Flare Energy Build-up in a Decaying Active Region Near a
Coronal Hole
Authors: Su, Yingna; van Ballegooijen, Adriaan; Schmieder, Brigitte;
Berlicki, Arkadiusz; Guo, Yang; Golub, Leon; Huang, Guangli
2009ApJ...704..341S Altcode:
A B1.7 two-ribbon flare occurred in a highly non-potential decaying
active region near a coronal hole at 10:00 UT on 2008 May 17. This
flare is "large" in the sense that it involves the entire region,
and it is associated with both a filament eruption and a coronal mass
ejection. We present multi-wavelength observations from EUV (TRACE,
STEREO/EUVI), X-rays (Hinode/XRT), and Hα (THEMIS, BBSO) prior to,
during and after the flare. Prior to the flare, the region contained
two filaments. The long J-shaped sheared loops corresponding to the
southern filament were evolved from two short loop systems, which
happened around 22:00 UT after a filament eruption on May 16. Formation
of highly sheared loops in the southeastern part of the region was
observed by STEREO 8 hr before the flare. We also perform nonlinear
force-free field (NLFFF) modeling for the region at two times prior
to the flare, using the flux rope insertion method. The models include
the non-force-free effect of magnetic buoyancy in the photosphere. The
best-fit NLFFF models show good fit to observations both in the corona
(X-ray and EUV loops) and chromosphere (Hα filament). We find that
the horizontal fields in the photosphere are relatively insensitive
to the present of flux ropes in the corona. The axial flux of the
flux rope in the NLFFF model on May 17 is twice that on May 16,
and the model on May 17 is only marginally stable. We also find that
the quasi-circular flare ribbons are associated with the separatrix
between open and closed fields. This observation and NLFFF modeling
suggest that this flare may be triggered by the reconnection at the
null point on the separatrix surface.

---------------------------------------------------------
Title: Magnetic Nonpotentiality Accumulation Prior to a "Large"
B1.7 Two-Ribbon Flare
Authors: Su, Yingna; van Ballegooijen, A.; Schmieder, B.; Berlicki,
A.; Guo, Y.; Golub, L.
2009SPD....40.2002S Altcode:
A B1.7 two-ribbon flare occurred in a highly non-potential decaying
active region near a coronal hole at 10:00 UT on May 17, 2008. This
flare is "large" in the sense that it involves the entire region, and
it is associated with both a filament eruption and a CME. We present
multi-wavelength observations from EUV (TRACE, STEREO/EUVI), X-rays
(Hinode/XRT), and H-alpha (THEMIS, BBSO) prior to, during and after
the flare. Prior to the flare, the observed coronal loops are mainly
two sets of highly sheared loops surrounding two filaments. The sheared
loops in the southern part of the region appeared in TRACE around 22:00
UT after a filament ejection on May 16. We also performed non-linear
force free field (NLFFF) modeling for the region prior to the flare,
using the flux rope insertion method. The model at 11:42 UT on May 16 is
based on THEMIS (vector) and MDI magnetograms, and the model at 08:03 UT
on May 17 is based only on MDI magnetogram. The best-fit NLFFF models
show good fit to observations both in the corona (X-ray and EUV loops)
and chromosphere (H-alpha filament). In the photosphere, the vectors
in the best-fit NLFFF model are similar to those in the potential
model. However, in the chromosphere, the vectors in the best-fit NLFFF
model present strong non-potentiality, especially at the end of the
inserted flux rope. We also found that the axial flux of the flux rope
in the NLFFF model on May 17 is much higher than that on May 16.

---------------------------------------------------------
Title: NLTE modelling of the flaring atmosphere above sunspot
Authors: Berlicki, A.; Heinzel, P.; Schmieder, B.; Li, H.
2008A&A...490..315B Altcode:
Aims: We performed an analysis of the solar flaring atmosphere above
sunspots. During the flare on October 20, 2003 many flaring structures
were observed projected onto the sunspots. We analysed the Hα and
Ca II line profiles emitted by the ribbons partially overlapping the
sunspots. In the penumbra, the line intensity in the far wings is lower
than in a typical quiet Sun profile but the core emission of Hα and
Ca II lines is typical for flares. We tried to find the structure of
the flare observed above the sunspot penumbra using the observations
of these chromospheric line profiles. Methods: NLTE radiative
transfer techniques allowed us to model the atmosphere of flaring
structures and fit both the synthetic Hα and Ca II line profiles to
the observed ones. We have derived semiempirical models of the flaring
structure observed above sunspots. Results: Our analysis shows
that the flare emission observed within the sunspot penumbra comes from
geometrically thin loop-like structures (cool flare loops) located
above the fibrils of the penumbra. The structure of the penumbra
located below the flare is almost not affected by the flare i.e. the
flare emission in Hα and Ca II comes not from the upper chromosphere
but from the structures that are higher in the corona. Therefore, a
two-component modelling is necessary to reproduce the flare emission
above the sunspot penumbra detected in our observations.

---------------------------------------------------------
Title: Hinode, TRACE, SOHO, and Ground-based Observations of a
Quiescent Prominence
Authors: Heinzel, P.; Schmieder, B.; Fárník, F.; Schwartz, P.;
Labrosse, N.; Kotrč, P.; Anzer, U.; Molodij, G.; Berlicki, A.;
DeLuca, E. E.; Golub, L.; Watanabe, T.; Berger, T.
2008ApJ...686.1383H Altcode:
A quiescent prominence was observed by several instruments on
2007 April 25. The temporal evolution was recorded in Hα by the
Hinode SOT, in X-rays by the Hinode XRT, and in the 195 Å channel by
TRACE. Moreover, ground-based observatories (GBOs) provided calibrated
Hα intensities. Simultaneous extreme-UV (EUV) data were also taken by
the Hinode EIS and SOHO SUMER and CDS instruments. Here we have selected
the SOT Hα image taken at 13:19 UT, which nicely shows the prominence
fine structure. We compare this image with cotemporaneous ones taken
by the XRT and TRACE and show the intensity variations along several
cuts parallel to the solar limb. EIS spectra were obtained about half
an hour later. Dark prominence structure clearly seen in the TRACE and
EIS 195 Å images is due to the prominence absorption in H I, He I,
and He II resonance continua plus the coronal emissivity blocking due
to the prominence void (cavity). The void clearly visible in the XRT
images is entirely due to X-ray emissivity blocking. We use TRACE, EIS,
and XRT data to estimate the amount of absorption and blocking. The
Hα integrated intensities independently provide us with an estimate of
the Hα opacity, which is related to the opacity of resonance continua
as follows from the non-LTE radiative-transfer modeling. However,
spatial averaging of the Hα and EUV data have quite different natures,
which must be taken into account when evaluating the true opacities. We
demonstrate this important effect here for the first time. Finally,
based on this multiwavelength analysis, we discuss the determination
of the column densities and the ionization degree of hydrogen in
the prominence.

---------------------------------------------------------
Title: Modelling of the Flare Observed Above Sunspot Penumbra
Authors: Berlicki, A.; Heinzel, P.; Schmieder, B.; Li, H.
2008ESPM...12.3.19B Altcode:
The solar flaring atmosphere above sunspot observed during the event
on October 20, 2003 was analysed. Many flaring structures were visible
in projection onto the sunspot penumbra. We analysed the H? and Ca
II line profiles emitted by the ribbons partially overlapping the
sunspots. These observations were performed with the Multi-channel
Infrared Solar Spectrograph (MISS) at Purple Mountain Observatory (PMO,
China). In the sunspot penumbra, the line intensity in far wings
is lower than in a typical quiet-Sun profile but in the line centre
the intensity of H? and Ca II lines is typical for flares. Using 1D
approximation we tried to find the vertical structure of the flare
observed above sunspot penumbra using the observations of these
chromospheric line profiles. NLTE radiative transfer techniques
allowed us to model the atmosphere of flaring structures and fit both
the synthetic H? and Ca II line profiles to the observed ones. We
have determined semiempirical models of the flaring structure observed
above sunspots. In our analysis we showed that the flare emission
observed within sunspot penumbra comes from geometrically thin loop-like
structures located above the fibrils of the penumbra. The structure
of the penumbra located below the flare is almost not affected by
the flare. The flare emission in chromospheric lines comes not from
the upper chromosphere but from the structures located higher in the
corona. Therefore, we performed two-component modelling which well
reproduce the flare emission above sunspot penumbra. In our model of
the flaring layer we included the transition region which is necessary
to obtain agreement between the observed and calculated line profiles.

---------------------------------------------------------
Title: Spectrophotometric analysis of Ellerman bombs in the Ca II,
Hα, and UV range
Authors: Pariat, E.; Schmieder, B.; Berlicki, A.; Deng, Y.; Mein,
N.; López Ariste, A.; Wang, S.
2007A&A...473..279P Altcode:
Context: Even if Ellerman bombs have been observed in the Hα line
within emerging magnetic flux regions since the early 20th century,
their origin and the mechanisms that lead to their formation have been
strongly debated. Recently, new arguments in favor of chromospheric
magnetic reconnection have been advanced. Ellerman bombs seem to be
the signature of reconnections that take place during the emergence
of the magnetic field. Aims: We have observed an active region
presenting emergence of magnetic flux. We detected and studied
Ellerman bombs in two chromospheric lines: Ca ii 8542 Å and Hα. We
investigated the link between Ellerman bombs and other structures and
phenomena appearing in an emerging active region: UV bright points,
arch filament systems, and magnetic topology. Methods: On August
3, 2004, we performed multi-wavelength observations of the active
region NOAA 10655. This active region was the target of SoHO Joint
Observation Program 157. Both SoHO/MDI and TRACE (195 Å and 1600 Å)
were used. Simultaneously, we observed in the Ca ii and Na D1 lines
with the spectro-imager MSDP mode of THEMIS. Alternately to the MSDP,
we used the MTR spectropolarimeter on THEMIS to observe in Hα and
in the Fe i doublet at 6302 Å. We derived the magnetic field vectors
around some Ellerman bombs. Results: We present the first images
of EBs in the Ca ii line and confirm that Ellerman bombs can indeed
be observed in the Ca ii line, presenting the same “moustache”
geometry profiles as in the Hα line, but with a narrower central
absorption in the Ca ii line, in which the peaks of emission are
around ±0.35 Å. We noticed that the Ellerman bombs observed in the
wings of Ca ii line have an elongated shape - the length about 50%
greater than the width. We derived mean semi-axis lengths of 1.4”
× 2.0”. In the UV time profiles of the Ellerman bombs, we noticed
successive enhanced emissions. The distribution of lifetimes of these
individual impulses presents a strong mode around 210 s. Study of the
magnetic topology shows that 9 out of the 13 EBs are located on the
inversion line of the longitudinal field and that some typical examples
might be associated with a bald patch topology. Conclusions: We
provide new arguments in favor of the reconnection origin of Ellerman
bombs. The different individual impulses observed in UV may be related
to a bursty mode of reconnection. We also show that this Ca ii 8542
Å chromospheric line is a good indicator of Ellerman bombs and can
bring new information about these phenomena.

---------------------------------------------------------
Title: Eruptive and Compact Flares
Authors: Schmieder, B.; Aulanier, G.; Delannée, C.; Berlicki, A.
2007AIPC..934...22S Altcode:
Solar two ribbon flares are commonly explained by magnetic field
reconnections in the high corona. During the reconnection energetic
particles (electrons and protons) are accelerated from the reconnection
site. These particles are following the magnetic field lines down
to the chromosphere. As the plasma density is higher in these lower
layers, there are collisions and emission of radiation. Thus after
the flare bright ribbons are observed at both ends of loops. These
ribbons are typically observed in Hα and in EUV with SoHO and
TRACE. As the time is going, these ribbons are expanding away of each
other. In most studied models, the reconnection site is an X-point,
where two magnetic separatrices intersect. They define four distinct
connectivity domains, across which the magnetic connectivity changes
discontinuously. In this paper, we present a generalization of this
model to 3D complex magnetic topologies where there are no null points,
but quasi-separatrices layers instead. In that case, while the ribbons
spread away during reconnection, we show that magnetic field lines
can quickly slip along them. We propose that this new phenomenon could
explain fast extension of Hα and TRACE 1600 Å ribbons, fast moving
HXR footpoints as observed by RHESSI, and that it is observed in soft
X rays with Hinode/XRT. We also show how this concept can be applied
to model the non-wave nature of EIT waves.

---------------------------------------------------------
Title: Spectrophotometry of Ellerman Bombs with THEMIS
Authors: Pariat, E.; Schmieder, B.; Berlicki, A.; López Ariste, A.
2007ASPC..368..253P Altcode:
During coordinated campaigns with THEMIS and space missions (TRACE,
SOHO) emerging flux was observed in multi-wavelengths. Ellerman bombs
(EBs) have been identified in TRACE 1600 Å and in chromospheric
lines. The Hα and Ca II 8542 Å lines present two enhanced emission
peaks respectively at 1 Å and at 0.35 Å which are signatures of
EBs. Vector magnetic field measured in the photosphere are consistent
with previous results indicating the presence of bald-patches under
the EBs and consequently the emergence of horizontal flux tubes from
below the photosphere.

---------------------------------------------------------
Title: Observations and Modeling of Line Asymmetries in Chromospheric
Flares
Authors: Berlicki, A.
2007ASPC..368..387B Altcode: 2007arXiv0704.2436B
For many years various asymmetrical profiles of different spectral
lines emitted from solar flares have been frequently observed. These
asymmetries or line shifts are caused predominantly by vertical
mass motions in flaring layers and they provide a good diagnostics
for plasma flows during solar flares. There are many controversial
results of observations and theoretical analysis of plasma flows in
solar chromospheric flares. The main difficulty is the interpretation
of line shifts or asymmetries. For many years, methods based on
bisector techniques were used but they give a reliable results only
for some specific conditions and in most cases cannot be applied. The
most promising approach is to use the non-LTE techniques applied
for flaring atmosphere. The calculation of synthetic line profiles
is performed with the radiative transfer techniques and the assumed
physical conditions correspond to flaring atmosphere. I will present
an overview of different observations and interpretations of line
asymmetries in chromospheric flares. I will explain what we have learnt
about the chromospheric evaporation in the frame of hydrodynamical
models as well as reconnection models. A critical review will be done
on the classical methods used to derive Doppler-shifts for optically
thick chomospheric lines. In particular, details on the new approach
for interpreting chromospheric line asymmetries based on the non-LTE
techniques will be presented.

---------------------------------------------------------
Title: What is the role of magnetic null points in large flares?
Authors: Schmieder, B.; Mandrini, C. H.; Démoulin, P.; Aulanier,
G.; Li, H.; Berlicki, A.
2007AdSpR..39.1840S Altcode:
We have performed the analysis of the magnetic topology of active
region NOAA 10486 before two large flares occurring on October 26
and 28, 2003. The 3D extrapolation of the photospheric magnetic field
shows the existence of magnetic null points when using two different
methods. We use TRACE 1600 Å and 195 Å brightenings as tracers of
the energy release due to magnetic reconnections. We conclude on the
three following points: The small events observed before the flares are
related to low lying null points. They are long lasting and associated
with low energy release. They are not triggering the large flares. On October 26, a high altitude null point is found. We look for
bright patches that could correspond to the signatures of coronal
reconnection at the null point in TRACE 1600 Å images. However,
such bright patches are not observed before the main flare, they are
only observed after it. On October 28, four ribbons are observed
in TRACE images before the X17 flare. We interpret them as due to a
magnetic breakout reconnection in a quadrupolar configuration. There
is no magnetic null point related to these four ribbons, and this
reconnection rather occurs at quasi-separatrix layers (QSLs). We
conclude that the existence of a null point in the corona is neither
a sufficient nor a necessary condition to give rise to large flares.

---------------------------------------------------------
Title: The Gradual Phase of the X17 Flare on October 28, 2003
Authors: del Zanna, G.; Schmieder, B.; Mason, H.; Berlicki, A.;
Bradshaw, S.
2006SoPh..239..173D Altcode: 2006SoPh..239..173Z; 2006SoPh..tmp...74Z
We present SOHO/CDS observations taken during the gradual phase of
the X17 flare that occurred on October 28, 2003. The CDS data are
supplemented with TRACE and ground-based observations. The spectral
observations allow us to determine velocities from the Doppler
shifts measured in the flare loops and in the two ribbon kernels,
one hour and a half after the flare peak. Strong downflows (&gt;70 km
s-1) are observed along the loop legs at transition-region
temperatures. The velocities are close to those expected for free
fall. Observations and results from a hydrodynamic simulation are
consistent with the heating taking place for a short time near the
top of the arcade. Slight upflows are observed in the outer edges of
the ribbons (&lt;60 km s-1) in the EUV lines formed at log
T &lt; 6.3. These flows could correspond to the so-called “gentle
evaporation.” At “flare” temperatures (Fe xix, log T = 6.9),
no appreciable flows are observed. The observations are consistent
with the general standard reconnection models for two-ribbons flares.

---------------------------------------------------------
Title: Is Pre-Eruptive Null Point Reconnection Required for Triggering
Eruptions?
Authors: Li, Hui; Schmieder, Brigitte; Aulanier, Guillaume; Berlicki,
Arkadiusz
2006SoPh..237...85L Altcode: 2006SoPh..tmp...22L; 2006SoPh..tmp...18L
We study the magnetic field evolution and topology of the active
region NOAA 10486 before the 3B/X1.2 flare of October 26, 2003,
using observational data from the French-Italian THEMIS telescope,
the Michelson Doppler Imager (MDI) onboard Solar and Heliospheric
Observatory (SOHO), the Solar Magnetic Field Telescope (SMFT) at
Huairou Solar Observation Station (HSOS), and the Transition Region
and Coronal Explorer (TRACE). Three dimensional (3D) extrapolation of
photospheric magnetic field, assuming a potential field configuration,
reveals the existence of two magnetic null points in the corona above
the active region. We look at their role in the triggering of the main
flare, by using the bright patches observed in TRACE 1600 Å images as
tracers at the solar surface of energy release associated with magnetic
reconnection at the null points. All the bright patches observed before
the flare correspond to the low-altitude null point. They have no
direct relationship with the X1.2 flare because the related separatrix
is located far from the eruptive site. No bright patch corresponds
to the high-altitude null point before the flare. We conclude that
eruptions can be triggered without pre-eruptive coronal null point
reconnection, and the presence of null points is not a sufficient
condition for the occurrence of flares. We propose that this eruptive
flare results from the loss of equilibrium due to persistent flux
emergence, continuous photospheric motion and strong shear along the
magnetic neutral line. The opening of the coronal field lines above
the active region should be a byproduct of the large 3B/X1.2 flare
rather than its trigger.

---------------------------------------------------------
Title: Magnetic Sources of Flares and CMEs from Multi-Wavelength
Flare Studies
Authors: Schmieder, B.; Mandrini, C.; Berlicki, A.; Démoulin, P.;
Li, H.
2006ESASP.617E.145S Altcode: 2006soho...17E.145S
No abstract at ADS

---------------------------------------------------------
Title: Magnetic Sources of flares and CMEs in October 2003
Authors: Schmieder, B.; Démoulin, P.; Berlicki, A.; Mandrini, C.;
Hui, Li
2006sf2a.conf..565S Altcode:
We present the data analysis of an observing campaign on October 2003
with the objective of understanding the onset of Coronal Mass Ejections
(CME) and solar flares. The magnetic field was observed with THEMIS
and MDI, the chromosphere with the MSDP operating on THEMIS, the EUV
images with SOHO/EIT and TRACE, the X-rays with RHESSI. Two examples
of flares will be presented: the 28 Oct 2003 X17 flare and the 20
October 2003 M1.9 flare. The magnetic field analysis of the active
regions is done using a linear-force-free field code. The X17 flare is
at the origin of a halo CME while the M1.9 flare has no corresponding
CME. Before the X17 flare there was a pre-flare event which allowed
to change the connectivities in a first phase and to destabilize the
stressed field in a second phase producing the X17 flare. A compact
twisted emerging flux was responsible of the M1.9 flare, which remains
a compact flare due to very tied overlaying loops. These two examples
illustrate the major role of the magnetic configuration involved on
the flare physical characteristics.

---------------------------------------------------------
Title: A Multi-Wavelength Study of the Compact M1 Flare on October
22, 2002
Authors: Zanna, G. Del; Berlicki, A.; Schmieder, B.; Mason, H. E.
2006SoPh..234...95Z Altcode:
In this paper we present a further study of the Ml class
flare observed on October 22, 2002. We focus on the SOHO Coronal
Diagnostic Spectrometer (CDS) spectral observations performed during a
multi-wavelength campaign with TRACE and ground-based instruments (VTT,
THEMIS). Strong blue-shifts are observed in the CDS coronal lines in
flare kernels during the impulsive phase of this flare. From a careful
wavelength calibration we deduce upflows of 140 km/s for the Fe XIX
flare emission, with a pattern of progressively smaller flows at lower
temperatures. Large line-widths were observed, especially for the Fe XIX
line, which indicate the existence of turbulent velocities. The strong
upflows correspond to full shifts of the line profiles. These flows
are observed at the initial phase of the flare, and correspond to the
"explosive evaporation". The regions of the blueshifted kernels, a few
arc seconds away from the flare onset location, could be explained by
the chain reaction of successive magnetic reconnections of growing
emerging field line with higher and higher overlying field. This
interpretation is evidenced by the analysis of the magnetic topology
of the active region using a linear force-free-field extrapolation of
THEMIS magnetograms.

---------------------------------------------------------
Title: A Multi-Wavelength Study of the Compact M1 Flare on October
22, 2002
Authors: del Zanna, G.; Berlicki, A.; Schmieder, B.; Mason, H. E.
2006SoPh..234...95D Altcode: 2006SoPh..234...95Z
In this paper we present a further study of the Ml class
flare observed on October 22, 2002. We focus on the SOHO Coronal
Diagnostic Spectrometer (CDS) spectral observations performed during a
multi-wavelength campaign with TRACE and ground-based instruments (VTT,
THEMIS). Strong blue-shifts are observed in the CDS coronal lines in
flare kernels during the impulsive phase of this flare. From a careful
wavelength calibration we deduce upflows of 140 km/s for the Fe XIX
flare emission, with a pattern of progressively smaller flows at lower
temperatures. Large line-widths were observed, especially for the Fe
XIX line, which indicate the existence of turbulent velocities. The
strong upflows correspond to full shifts of the line profiles. These
flows are observed at the initial phase of the flare, and correspond
to the “explosive evaporation”. The regions of the blueshifted
kernels, a few arc seconds away from the flare onset location, could be
explained by the chain reaction of successive magnetic reconnections of
growing emerging field line with higher and higher overlying field. This
interpretation is evidenced by the analysis of the magnetic topology
of the active region using a linear force-free-field extrapolation of
THEMIS magnetograms.

---------------------------------------------------------
Title: Hard X-ray emission at the footpoints of solar flares
Authors: Falewicz, R.; Siarkowski, M.; Berlicki, A.
2006AdSpR..38..956F Altcode:
We analyse X-ray flare observations made by the Soft X-ray Telescope
and Hard X-ray Telescope on the Yohkoh satellite during period 1999
2001. For the strongest flares, when HXT imaging with high time cadence
(0.5 1 s) is possible, clear changes in the asymmetry of the observed
footpoints fluxes are revealed. We present four examples of flares
which illustrate such asymmetrical time variations the best. Observed
asymmetries are usually interpreted as due to a difference in magnetic
field strength or field divergence at the footpoints, however this
interpretation should lead to the existence of strong magnetic field
oscillations or movements of the footpoints’ locations in the presence
of strong magnetic gradients. Our analysis indicates rather that either
differences in the electron injection or electron distribution in each
loop’s leg is the source of the observed asymmetry variations. We
discuss possible mechanisms which may be responsible for such effect.

---------------------------------------------------------
Title: THEMIS/MSDP magnetic field measurements
Authors: Berlicki, A.; Mein, P.; Schmieder, B.
2006A&A...445.1127B Altcode:
We present an analysis of longitudinal magnetic field measurements
using the spectral data obtained with the French - Italian
polarisation free telescope THEMIS working in Multichannel Subtractive
Double Pass (MSDP) mode. We also used SOHO/MDI data to extend our
analysis. THEMIS observations in the MSDP mode allows us to perform
imaging spectropolarimetry characterized by high spatial and time
resolution. In our analysis we used the observations of solar active
region NOAA 10484 performed on October 20, 2003. From THEMIS 2D
spectral images recorded in Na D1 5896 Å line we obtained
the longitudinal magnetic field in the active region. The value of
the magnetic field was calculated at different distances from the
Na D1 line centre. We determine the LOS magnetic field at
different heights in the solar atmosphere. SOHO/MDI observations provide
the longitudinal magnetic field in Ni I (6768 Å) line. THEMIS/MSDP
measurements at Δλ= 0.30 Å are similar to SOHO/MDI results. Gradients
of longitudinal magnetic fields derived from MSDP measurements at Δλ=
0.08 and Δλ=0.24 Å exhibit different behaviours according to solar
targets. A decrease with height is seen in spot umbrae and penumbrae,
while the gradient in facular and network areas suggests a slight
increase of the longitudinal magnetic field, which might be explained
by the 3D-structure of canopies.

---------------------------------------------------------
Title: Magnetic Topology before a 3B/X1.2 Flare and the Associated CME
Authors: Li, H.; Schmieder, B.; Aulanier, G.; Berlicki, A.
2006IAUS..233..399L Altcode:
We extrapolated observed photospheric magnetic field before the 3B/X1.2
flare occurred in NOAA 10486 on 2003 October 26. Two magnetic null
points exist above the active region, which have no crucial role in
triggering the flare, even though enhanced TRACE EUV/UV emission was
observed before the main flare due to magnetic reconnection near the
lower-altitude null point. We conclude that this flare results from the
loss of equilibrium due to persistent flux emergence and photospheric
motion, and strong shear. The accompanying fast CME with velocity of
∼ 800 km s^{-1} shows quick mass pickup and energy increase in the low
corona. Its kinetic energy is always larger than its potential energy.

---------------------------------------------------------
Title: Small GOES flares with intense hard X-ray emission
Authors: Siarkowski, M.; Falewicz, R.; Berlicki, A.
2006AdSpR..38..972S Altcode:
Large solar flares with intense soft X-ray emission (i.e., high GOES
class) generally tend to show a strong hard X-ray emission. However,
there are examples of low GOES class events with unusually strong hard
X-ray emission. In this paper, we analyse the morphology and physical
parameters of such small GOES intensity flares with strong hard X-ray
emission, using Yohkoh SXT images and photometric data obtained from
INTERBALL-TAIL RF15-I X-ray Photometer. We observe a great variety
in the soft X-ray morphology of such flares (a large diversity of
loop configurations). Some of these flares do not differ greatly
in their morphology from large intense flares, but most flares are
generally compact. In spite of their low intensities in soft X-rays,
the significant hard X-ray emission is observed by INTERBALL up to
30 60 keV. We briefly discuss some of the possible causes of the soft
and hard X-ray emission ratio of these events.

---------------------------------------------------------
Title: On Line Profile Asymmetries in a Solar Flare
Authors: Prosecký, T.; Kotrč, P.; Berlicki, A.
2006CEAB...30...31P Altcode:
To detect vertical velocity fields from observed Hα profiles
we analyse spectral line profile asymmetries in the flare on August
10, 2003. In addition to a bisector method we use a comparison of the
observed and non-LTE calculated profiles. In most of the analysed
flare kernels we detect a weak blue asymmetry and interpret it in
terms of a downward motion. Capacities and results of the two methods
are compared and discussed.

---------------------------------------------------------
Title: Magnetic reconfiguration before the X 17 Solar flare of
October 28 2003
Authors: Schmieder, B.; Mandrini, C. H.; Démoulin, P.; Pariat, E.;
Berlicki, A.; Deluca, E.
2006AdSpR..37.1313S Altcode:
An active region (AR) NOAA 10486, which produced a large number of
X-ray flares during October November 2003, was observed during a
multi-wavelength campaign with ground based and space instruments. We
focus our analysis on the observations of October 28, 2003. The
magnetic field was observed with THEMIS (Na D1) and MDI (Ni I), the
chromosphere with THEMIS (Ca II 8542 Å) and with the Meudon heliograph
in Hα, the EUV images with SOHO/EIT and TRACE. Two pre-events started
just before the major X 17 flare. One was related to localized flux
emergence and lasted until the decay phase of the X flare; while the
second one involved a large scale quadrupolar reconnection, that we
infer by modeling the AR magnetic field. Extended dimming areas across
the equator (EIT), large arcades of post-flare loops (TRACE 195 Å)
and a halo CME (LASCO) were observed consequently after the flare. We
perform an extrapolation of the magnetic field above the photosphere
using a linear force-free-field approximation that allows us to find
the connectivity among the four polarities that would be involved
in the quadrupolar reconnection event. The X 17 flare is plausibly
due to the destabilisation of a twisted flux tube, the bottom part
of this magnetic structure can be visualized by the presence of a
filament. The destabilization is caused by converging and shearing
photospheric motions towards the main magnetic inversion line. The
large scale quadrupolar reconnection related to the second pre-event
would favour the opening of the field above the twisted flux tube and,
consequently, the coronal mass ejection.

---------------------------------------------------------
Title: Active Region Magnetic Field Observed with Themis/msdp and
Soho/mdi Instruments
Authors: Berlicki, A.; Mein, P.; Schmieder, B.
2005ESASP.600E..57B Altcode: 2005ESPM...11...57B; 2005dysu.confE..57B
No abstract at ADS

---------------------------------------------------------
Title: Multi-Wavelength Analysis of Plasma Flows during Solar Flares
Authors: Berlicki, A.; Schmieder, B.; Heinzel, P.; Li, H.; Del Zanna,
G.; Rudawy, P.
2005ESASP.600E..58B Altcode: 2005dysu.confE..58B; 2005ESPM...11...58B
No abstract at ADS

---------------------------------------------------------
Title: A Multi-Wavelength Study of the 3B/X1.2 Flare Observed on
2003 October 26
Authors: Li, Hui; Li, Jian-Ping; Fang, Cheng; Schmieder, Brigitte;
Berlicki, Arkadiusz; Du, Qiu-Sheng
2005ChJAA...5..645L Altcode:
We report results from a multi-wavelength study of the 3B/X1.2
two-ribbon disk flare (S15E44), which was well observed by both
ground-based and space-borne instruments. Two pairs of conjugate kernels
K1 and K4, and K2 and K3 in the Hα images are identified. These kernels
are linked by two different systems of EUV loops. K1 and K4 correspond
to the two 17 GHz and 34 GHz microwave sources observed by the Nobeyama
Radioheliograph (NoRH), while K2 and K3 have no corresponding microwave
sources. Optical spectroscopic observations suggest that all the four
kernels are possible precipitating sites of non-thermal electrons. Thus
the energy of electron deposited in K2 and K3 should be less than 100
keV. Two-dimensional distributions of the full widths at half maximum
(FWHM) of the Hα profiles and the line-of-sight (LOS) velocities
derived from the Ca II 8542 Å profiles indicate that the largest
FWHM and LOS velocity tends to be located near the outer edges of Hα
kernels, which is consistent with the scenario of current two-ribbon
flare models and previous results. When non-thermal electron bombardment
is present, the observed Hα and Ca II 8542 Å profiles are similar to
previous observational and theoretical results, while the He I 10830
Å profiles are different from the theoretical ones. This puts some
constraints on future theoretical calculation of the He I 10830 Å line.

---------------------------------------------------------
Title: Flows and Heating of the Solar Atmosphere during Solar Flares
Authors: Schmieder, B.; Berlicki, A.; Li, H.; Del Zanna, G.; Mason, H.
2005ESASP.592..543S Altcode: 2005soho...16E.102S; 2005ESASP.592E.102S
No abstract at ADS

---------------------------------------------------------
Title: Thermal and non-thermal effects driven by magnetic
reconnections observed in a confined flare
Authors: Li, H.; Berlicki, A.; Schmieder, B.
2005A&A...438..325L Altcode:
In order to better understand the energy processes occurring during
the impulsive phase of solar flares we compare observations with our
magnetic model calculations. We study the 1N/M1.9 confined flare of
20 October 2003 observed during a Joint Observation Program (JOP157),
and concentrate on the spectral analysis of the Reuven Ramaty High
Energy Solar Spectroscopic Imager (RHESSI). These X-ray observations
are combined with those from the Solar and Heliospheric Observatory
(SOHO) instruments, the French Italian magnetograph (THEMIS), and the
Multi-channel Infrared Solar Spectrograph (MISS). The flare occurred
in a complex active region, NOAA 10484, with a δ configuration. For
model calculations we extrapolate magnetic field lines, which allows
us to understand the magnetic topology of the region. This topology
and the long impulsive phase of the flare with numerous peaks (GOES,
RHESSI) suggest multiple magnetic field reconnection processes. The
RHESSI images show a bright structure in hard X-rays (HXR) that could
be the tops of the loops. We measure a significant displacement
of this structure between the two main maxima of emission, which
infers different sites for the reconnection process. The energy
release processes can be understood by analyzing the RHESSI spectra
using different models. First, using the thermal plus broken power law
non-thermal component, we derive the low energy cutoff for the power law
distribution of the high-energy electrons (≈25 keV). Then, we apply
two models (thermal plus thick-target and thermal plus thin-target
non-thermal component) that allow us to fit the observations. These
two models lead to similar results; non-thermal energy contributes a
significant amount (approximately 20%) of the total flare energy only
during the first peak of the impulsive phase. This suggests that the
energy that heats the chromosphere is transported mainly by thermal
conduction. The temperature of the thermal plasma is 34 MK and 20 MK
at the first and second peaks, respectively.

---------------------------------------------------------
Title: Non-LTE diagnostics of velocity fields during the gradual
phase of a solar flare
Authors: Berlicki, A.; Heinzel, P.; Schmieder, B.; Mein, P.; Mein, N.
2005A&A...430..679B Altcode:
We perform an analysis of the velocity field within the Hα ribbons
during the gradual phase of an M 1.0 solar flare observed on October 22,
2002. We use spectroscopic observations performed with the German VTT
(Vacuum Tower Telescope) working in the MSDP (Multichannel Subtractive
Double Pass spectrograph) observing mode. From these observations
the Hα line profiles in chosen areas of the flare ribbons were
reconstructed and these observational profiles were compared with
a grid of synthetic Hα line profiles calculated by the non-LTE
radiative-transfer code. This code allows us to calculate different
models of the chromosphere with a prescribed velocity field. By
optimising the best fit between the observed and synthetic profiles
we find the most appropriate models of the chromosphere and vertical
structure of the velocity field in the analysed areas of the flare
ribbons. By means of the non-LTE radiative-transfer calculations
we show that in most analysed areas of the Hα flare ribbons the
chromospheric plasma exhibited upward motion with a mean velocity of
a few km;s-1. These results are consistent with previous
estimates and support the scenario of a gentle evaporation during the
gradual phase.

---------------------------------------------------------
Title: Evolution and magnetic topology of the M 1.0 flare of October
22, 2002
Authors: Berlicki, A.; Schmieder, B.; Vilmer, N.; Aulanier, G.;
Del Zanna, G.
2004A&A...423.1119B Altcode:
In this paper we analyse an M 1.0 confined flare observed mainly
during its gradual phase. We use the data taken during a coordinated
observational campaign between ground based instruments (THEMIS and
VTT) and space observatories (SoHO/CDS and MDI, TRACE and RHESSI). We
use these multi-wavelength observations to study the morphology
and evolution of the flare, to analyse its gradual phase and to
understand the role of various heating mechanisms. During the flare,
RHESSI observed emission only within the 3-25 keV spectral range. The
RHESSI spectra indicate that the emission of the flare was mainly of
thermal origin with a small non-thermal component observed between
10 and 20 keV. Nevertheless, the energy contained in the non-thermal
electrons is negligible compared to the thermal energy of the flaring
plasma. The temperature of plasma obtained from the fitting of the
RHESSI X-ray spectra was between 8.5 and 14 MK. The lower temperature
limit is typical for a plasma contained in post flare loops observed
in X-rays. Higher temperatures were observed during a secondary peak
of emission corresponding to a small impulsive event. The SoHO/CDS
observations performed in EUV Fe XIX line also confirm the presence
of a hot plasma at temperatures similar to those obtained from RHESSI
spectra. The EUV structures were located at the same place as RHESSI
X-ray emission. The magnetic topology analysis of the AR coming from a
linear force-free field extrapolation explains the observed features
of the gradual phase of the flare i.e. the asymmetry of the ribbons
and their fast propagation. The combination of the multi-wavelength
observations with the magnetic model further suggests that the onset
of the flare would be due to the reconnection of an emerging flux in
a sheared magnetic configuration.

---------------------------------------------------------
Title: Soft X-ray heating of the solar chromosphere during the
gradual phase of two solar flares
Authors: Berlicki, A.; Heinzel, P.
2004A&A...420..319B Altcode:
In this paper we perform an analysis of the energetics of the solar
flaring chromosphere irradiated by soft X-rays (SXR) emitted from
overlying hot flare loops. To study an expected SXR heating we used
the observations of two solar flares obtained with the Multichannel
Subtractive Double Pass (MSDP) spectrograph attached to the Large
Coronagraph of the Wrocław University. SXR observations of these flares
come from the Yohkoh SXR telescope (SXT). From MSDP spectral images
we derived mean Hα line profiles which were then used to construct
semi-empirical non-LTE models of the chromosphere in the analyzed areas
of flares. On the basis of SXR observations we calculated the mean
emission measure EM and the temperature in flaring coronal structures
located above the Hα kernels under study and these two quantities were
used to compute the SXR irradiation of the chromosphere between 1-300
Å. For each flare model we then evaluated the energy deposit due to
such irradiation and compared it with the net radiative cooling rates
at all depths in the chromosphere. By means of such modelling we were
able to demonstrate that the enhanced emission of selected Hα kernels
observed during the gradual phase of these two solar flares cannot be
explained in terms of the SXR heating of the chromosphere. We found
that radiative losses in all layers of the chromosphere exceeded
the amount of the energy deposited by the SXR radiation. However,
for stronger flares with much enhanced EM a certain contribution of
SXR to the heating cannot be ruled out.

---------------------------------------------------------
Title: Neupert effect in solar flares
Authors: Berlicki, A.; Falewicz, R.
2004cosp...35.2204B Altcode: 2004cosp.meet.2204B
Tha data obtained with Reuven Ramaty High Energy Solar Spectroscopic
Imager (RHESSI) were used to investigate the Neupert effect in a
few solar flares. RHESSI is capable to observe the X-ray emission
with high time resolution within a very wide energy range (from 3
keV to 17 MeV) and therefore is exceptionally useful to analyse this
effect. We used the observations of rather strong events, where the
X-ray flux was detected by RHESSI up to high energies. We analysed the
time profiles of 'soft' and 'hard' X-ray fluxes observed in diferent
energy bands. Our analysis indicates that the time derivatives of X-ray
fluxes in low-energy channels are in general agreement with the time
profiles of hard X-ray emission observed by RHESSI above 30 keV. The
results support the previous analysis of Neupert effect based on the
observations obtained with YOHKOH satellite.

---------------------------------------------------------
Title: Multi-wavelength flare study and magnetic configuration
Authors: Schmieder, Brigitte; Berlicki, A.; Vilmer, N.; Aulanier,
G.; Démoulin, P.; Mein, P.; Mandrini, C.; Deluca, E.
2004IAUS..223..397S Altcode: 2005IAUS..223..397S
Recent results of two observation campaigns (October 2002 and October
2003) are presented with the objective of understanding the onset
of flares and CMEs. The magnetic field was observed with THEMIS and
MDI, the chromosphere with the MSDP operating on the German telescope
VTT and on THEMIS, the EUV images with SOHO/CDS and TRACE, the X-ray
with RHESSI. We show how important is the magnetic configuration of
the active region to produce CMEs using two examples: the October 28
2003 X 17 flare and the October 22 2002 M 1.1 flare. The X 17 flare
gave a halo CME while the M 1.1 flare has no corresponding CME. The
magnetic topology analysis of the active regions is processed with a
linear-force-free field configuration.

---------------------------------------------------------
Title: Small GOES flares with intense hard X-ray emission
Authors: Siarkowski, M.; Falewicz, R.; Berlicki, A.
2004cosp...35.3384S Altcode: 2004cosp.meet.3384S
During the period of low solar activity numerous flares of GOES class B
and early C can be observed. Part of them has quite strong hard X-ray
emission (above 20 keV). We are looking for such events using data
obtained from BATSE and/or RF15-I X-ray photometer aboard INTERBALL-Tail
satellite for the period between January 1994 and November 1998. We
analyse morphology and physical parameters of these small flares using
the Yohkoh SXT images.

---------------------------------------------------------
Title: Multi-Wavelength Observations of an M1.0 Flare on 22 October
2002
Authors: Berlicki, A.; Schmieder, B.; Vilmer, N.; Mein, P.; Mein,
N.; Heinzel, P.; Staiger, J.; Deluca, E. E.
2004IAUS..219..669B Altcode:
No abstract at ADS

---------------------------------------------------------
Title: H-alpha spectral observations of the X17+ solar flare on 28
october 2003
Authors: Radziszewski, K.; Rudawy, P.; Schmieder, B.; Berlicki, A.
2004cosp...35.1248R Altcode: 2004cosp.meet.1248R
In this paper we present the results of H-alpha observations of the
giant X17+ GOES class solar flare on 28 October 2003. The observational
data were collected with the Large Coronagraph and MSDP spectrograph of
the Astronomical Observatory of Wroclaw University (Poland). During
the nearly 3.5 hours of observations we have collected 176 scans
covering the whole flaring region (200 000 x 240 000 km2). After
the standard data reduction we have obtained quasi-monochromatic 2D
images of the flare as well as H-alpha line profiles (+/-0.12 nm)
for all pixels of the images. The temporal resolution of our data
is equal to about 50 second; the spatial resolution is of the order
of 1 second of arc. In this paper we present the main properties of
the H-alpha flare: translations of the flare kernels, motion of the
matter along the arcade of the H-alpha loops, comparison of the H-alpha
structures with ones observed in UV by TRACE and SOHO as well as with
magnetograms and numerical models of the magnetic fields and emission
of the flaring kernels.

---------------------------------------------------------
Title: Flare evolution and magnetic configuration study
Authors: Berlicki, A.; Schmieder, B.; Aulanier, G.; Vilmer, N.; Yan,
Y. H.
2004cosp...35.2200B Altcode: 2004cosp.meet.2200B
We will present the analysis of M1.0 confined flare emission and
evolution in the context of the topology of the coronal magnetic
field. This flare was observed in NOAA 0162 on 22 October 2002. The
multiwavelength data were taken during a coordinated observational
campaign between ground based instruments and space observatories. The
photospheric line-of-sight magnetic field observations were obtained
with THEMIS and SOHO/MDI. We used these data to perform linear
force-free field extrapolation of magnetic field into the corona. Our
extrapolation provides an explanation of the appearance of H-alpha
flare ribbons. An elongated shape of X-ray emission observed by Reuven
Ramaty High Energy Solar Spectroscopic Imager (RHESSI) also follow
the predicted shape of extrapolated field lines. Moreover, the X-ray
emission observed by RHESSI permit to see thermal emission of coronal
loops heated probably by non-thermal electrons, accelerated during the
reconnection processes. The presence of non-thermal particles can be
deduced from RHESSI X-ray spectra reconstructed during the gradual phase
of the flare. On Huairou vector magnetograms of the AR we see that there
was strong shear between one of main negative spot and the north small
positive spot. The extrapolation with non-constant alpha force-free
field model did not obtain any loop to connect these two spots.

---------------------------------------------------------
Title: Hard X-ray emission at the footpoints of solar flares
Authors: Falewicz, R.; Siarkowski, M.; Berlicki, A.
2004cosp...35.1257F Altcode: 2004cosp.meet.1257F
We analyze hard and soft X-ray observations from the SXT and HXT
instruments on the Yohkoh satellite of a few flares of 2000 year. For
the strongest events, when the Yohkoh Hard X-ray Telescope imaging
with high time cadences (0.5 - 1 sec) is possible, we have revealed
clear changes in the asymmetry of the observed footpoints fluxes. We
investigate also carefully such characteristics as spectral index
variation or footpoints movements during the flare. Observed asymmetry
is usually interpreted as an effect of the difference in magnetic field
strength or the field divergence at the footpoints. Such traditional
interpretation should lead to the existence of strong magnetic
field oscillations or movements of the footpoints' locations in the
presence of strong magnetic gradient. Our analysis indicates rather
the differences in the injection conditions in each loop's leg as a
source of the observed asymmetry variations. We analyze few possible
mechanisms which may be responsible for observed effect.

---------------------------------------------------------
Title: Soft X-ray Heating of Stellar Chromospheres
Authors: Heinzel, P.; Berlicki, A.
2003IAUS..210P.B15H Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Soft X-ray heating of the solar chromosphere: gradual phase
of a solar flare
Authors: Berlicki, A.; Heinzel, P.; Jakimiec, J.
2002ESASP.506..549B Altcode: 2002svco.conf..549B; 2002ESPM...10..549B
In this paper we present the analysis of energetics of solar flaring
chromosphere heated by soft X-ray radiation coming from overlying
hot flare loops. During the solar flare, a large amount of its energy
is emitted from hot coronal part in soft X-ray spectral range. This
radiation can penetrate into the chromosphere and transmit the
energy. This additional heating modifies vertical structure of the
chromosphere and it can cause the enhanced emission from some parts of
the flare. Therefore, such a mechanism can be responsible for emission
of chromospheric flaring structures commonly observed in Hα and other
spectral lines during the gradual phases when non-thermal processes
are unimportant. To analyze the effect of X-ray heating we used the
observations of the solar flare of 25 September 1997. This flare
was observed with the Wroclaw Multichannel Subtractive Double Pass
spectrograph (MSDP) coupled with the Large Coronagraph. We also use
X-ray observations of the flare taken with the SXT telescope. Within
the approximation of the quasi steady-state we have calculated the
deposit of X-ray energy in the chromosphere. By means of the non-LTE
radiative transfer calculations we show that enhanced emission of some
H-alpha structures observed during the gradual phase of this solar
flare can be partially explained in terms of the soft X-ray heating of
the chromosphere by hot 'post-flare' loops seen on the SXT images. We
also analyzed the energy budget of X-ray heated flaring chromosphere
and found that radiative losses from the chromosphere can be balanced
by soft X-ray heating only in some layers of the solar chromosphere.

---------------------------------------------------------
Title: Search for short period coronal plasma oscillations. SECIS
results from 1999 and 2001 total eclipses
Authors: Rudawy, P.; Phillips, K. J. H.; Read, P.; Gallagher, P. T.;
Rompolt, B.; Berlicki, A.; Williams, D.; Keenan, F. P.; Buczylko, A.
2002ESASP.506..967R Altcode: 2002ESPM...10..967R; 2002svco.conf..967R
Results of the analysis of the high-cadence observations of the solar
corona, taken with the Solar Eclipse Coronal Imaging System instrument
during joint British-Polish expeditions during the total solar eclipses
of 1999 August 11 in Bulgaria (12768 images) and 2001 June 21 in Zambia
(16000 images) are presented. Using data collected during the both solar
eclipses we searched for possible periodic changes of the 530.3 nm line
intensity emitted by the selected points of the solar corona in the
frequency range up to 10 Hz. The time resolution of the collected data
is close to 0.05 sec and the pixel size is approximately 4 seconds of
arc. The standard photometric processing and correction of the image
motions caused by temporal drifts of the instrument pointing were
made. Using classical Fourier spectral analysis and wavelet analysis
tools we investigated temporal changes of the 530.3 nm coronal line
brightness of many thousands of points at various heights and position
angles above the solar limb. We did not find any statistically important
evidence of periodicity in the frequency range from 1 to 10 Hz in any
of the investigated points.

---------------------------------------------------------
Title: Hot plasma motion observed in sigmoidal loop during the flare
in NOAA 8323 active region on 4 September 1998
Authors: Berlicki, A.; Rudawy, P.; Siarkowski, M.; Jurecki, M.
2002AdSpR..30..605B Altcode:
We present a study of the hot plasma motion in a sigmoidal loop during
the C2.2 class solar flare in NOAA 8323 active region on 4 September
1998. In our work we analysed spectra and images taken with Wrocław
Large Coronagraph coupled with Multi-Channel Subtractive Double Pass
Spectrograph and Hα camera, Yohkoh Soft X-ray Telescope, Yohkoh Bragg
Crystal Spectrometer, whole-disk integrated X-ray flux measurements
made by GOES and INTERBALL RF15-I photometer as well as radio flux
measurements taken with Ondrejov RT3 radiotelescope. The SXT images
reveal an expansion of the X-ray flare kernels along the both legs
of the sigmoidal loop toward the loop-top. Assuming circular shape of
the loop we calculated full velocity vectors of the kernels and their
line-of-sight components. The calculated line-of-sight velocities were
of the same order as velocities evaluated from BCS spectra. We suppose
that observed event was direct manifestation of the plasma evaporation
in the flaring loop.

---------------------------------------------------------
Title: Ejection during the solar flare in NOAA 8739 active region
on 26 October 1999
Authors: Rudawy, P.; Berlicki, A.; Siarkowski, M.; Kasiniak, K.
2002AdSpR..30..611R Altcode:
We analysed a huge ejection of the matter along an extended system of
the magnetic loops in NOAA 8739 active region on 26 October 1999. The
study was made using high cadence ground-base Multi-Channel Double
Pass Spectrograph Hα spectra, TRACE 171 Å and 195 Å ultraviolet,
Yohkoh Soft X-ray Telescope images and INTERBALL RF15-I 2-30 keV
photometer X-ray measurements. We found the following: The ejection
was associated with a C6.5 GOES class solar flare with precursor. The
ejection consisted of two distinct stages. The cool matter, visible
in Hα line, was ejected at first, after the precursor but before the
impulsive phase of the flare. The hotter plasma, visible in UV lines,
was ejected two minutes later just before the impulsive phase. The
kinetic energy of the ejected Hα matter was relatively low and only
a fraction of the matter was transferred to the opposite footpoints
of the loop system. The significant part of the matter fell back
into the ejection region. A new magnetic field emerged from below
the chromosphere in the flaring region just after the ejection. The
field was visualised as a co-linear system of the dark loops and
fibrils. They then merged with the adjacent filament, extending its
length. All flare-like Hα brightenings (with flat or reversed profiles)
in the whole active region occurred simultaneously or just after the
very distinct increases of the X-ray signal recorded in the 10-15 keV
channel. The increases of the signals recorded in the softer channels
were much less distinct or did not occur in all. The profiles of the
Hα line emitted by the flaring kernels were significantly shifted to
the red.

---------------------------------------------------------
Title: Multi-wavelength observations of the flares in NOAA 8307
active region
Authors: Siarkowski, M.; Rudawy, P.; Berlicki, A.
2002AdSpR..30..583S Altcode:
We analyse in detail a series of four solar flares observed in NOAA
8307 active region on 18 and 19 August 1998 using ground-based Hα
and space-based X-ray observations. All the four analysed flares had
very similar structure. The observed changes in their morphology and
physical properties can be attributed to the gradual changes of the
macroscopic magnetic fields of the active region.

---------------------------------------------------------
Title: Interpretation of the MSDP Hα line profiles recorded during
the gradual phase of a solar flare
Authors: Berlicki, A.; Rudawy, P.; Rompolt, B.
2002AdSpR..30..595B Altcode:
In our paper we presented the results of analysis of Hα line profiles
emitted by some bright flaring structures observed during the gradual
phase of the C7.2 X-ray class flare. The flare was observed in NOAA 8088
active region on 25 September 1997 at 11:50 UT. We have used Hα line
spectra obtained with the Wrocław Multichannel Subtractive Double Pass
Spectrograph for all the points of the recorded field of view with the
temporal resolution of the order of 2 minutes. We analysed the time
evolution of the Hα profiles emitted by some selected structures of
the flare. We found that during the gradual phase of the flare the
Hα spectra exhibited mainly redshifts. The line of sight velocities,
corresponding to these shifts, did not exceed +13 km s -1. We
found that only few very small areas outside the flare structures
showed blueshifted spectra. Hα emission kernels located probably
close to X-ray loops footpoints also exhibited redshifted line
profiles. In contrast, the modelling made by Antiochos and Sturrock
(1978) as well as by Acton et al. (1982) predict the existence of a
"gentle evaporation" of plasma heated during the thermal phase of the
flares. Such a gentle upward motion of the chromospheric plasma should
produce mostly blueshifted profiles of the observed chromospheric
spectral lines (Schmieder et al., 1987).

---------------------------------------------------------
Title: Cornoal Heating by MHD Waves: Results from the SECIS Instrument
during the 1999 Eclipse
Authors: Phillip, K. J. H.; Gallagher, P. T.; Williams, D. R.; Keenan,
F. P.; Rudawy, P.; Rompolt, B.; Berlicki, A.
2001IAUS..203..467P Altcode:
We report on observational evidence for the rôles that small flare-like
events and short-period MHD waves play in the heating of the solar
corona. In several studies of SOHO and Yohkoh data, we examine the
numbers and energies of small events in the EUV and in soft X-rays
can account for the necessary energetics of the quiet-Sun corona,
finding that EUV events at least might be sufficient to provide the
heating, at least in closed-field regions. Results will be summarized
in this paper. However, MHD waves may still play an important part,
and in a separate investigation we have used fast-cadence imaging of
the white-light and green-line corona during the total eclipse of 1999
August 11 to search for short-period modulations. The imaging system
is the Solar Eclipse Coronal Imaging System (SECIS), and consists of a
pair of CCD cameras and an adapted PC to form images of the corona at
a frame rate of 44 s-1. Preliminary analysis of the data
suggests the presence of fast changes over the 2-minute-long period
of eclipse totality. This paper will also report on the SECIS data.

---------------------------------------------------------
Title: SECIS: The Solar Eclipse Coronal Eclipse Imaging System
Authors: Phillips, K. J. H.; Read, P. D.; Gallagher, P. T.; Keenan,
F. P.; Rudawy, P.; Rompolt, B.; Berlicki, A.; Buczylko, A.; Diego,
F.; Barnsley, R.; Smartt, R. N.; Pasachoff, J. M.; Babcock, B. A.
2000SoPh..193..259P Altcode:
The Solar Eclipse Coronal Imaging System (SECIS) is an instrument
designed to search for short-period modulations in the solar corona
seen either during a total eclipse or with a coronagraph. The CCD
cameras used in SECIS have the capability of imaging the corona at a
rate of up to 70 frames a second, with the intensities in each pixel
digitised in 12-bit levels. The data are captured and stored on a
modified PC. With suitable optics it is thus possible to search for
fast changes or short-period wave motions in the corona that will
have important implications for the coronal heating mechanism. The
equipment has been successfully tested using the Evans Solar Facility
coronagraph at National Solar Observatory/Sacramento Peak and during
the 11 August 1999 eclipse at a site in north-eastern Bulgaria. The
instrument is described and preliminary results are outlined.

---------------------------------------------------------
Title: Hα Spectral and X-ray Observations of the Solar Flare on 2
May 1998
Authors: Berlicki, A.; Falewicz, R.; Rudawy, P.
1999ESASP.448..759B Altcode: 1999ESPM....9..759B; 1999mfsp.conf..759B
No abstract at ADS

---------------------------------------------------------
Title: Rotational motion of material in surges
Authors: Rompolt, B.; Mińko-Wasiluk, A.; Berlicki, A.
1998PAICz..88..225R Altcode:
No abstract at ADS

---------------------------------------------------------
Title: Evidence for prolonged acceleration based on a detailed
analysis of the long-duration solar gamma-ray flare of June 15, 1991
Authors: Akimov, V. V.; Ambrož, P.; Belov, A. V.; Berlicki, A.;
Chertok, I. M.; Karlický, M.; Kurt, V. G.; Leikov, N. G.; Litvinenko,
Yu. E.; Magun, A.; Minko-Wasiluk, A.; Rompolt, B.; Somov, B. V.
1996SoPh..166..107A Altcode:
Gamma-ray emission extending to energies greater than 2 GeV and lasting
at least for two hours as well as 0.8-8.1 MeV nuclear line emission
lasting 40 min were observed with very sensitive telescopes aboard
the GAMMA and CGRO satellites for the well-developed post-flare loop
formation phase of the 3B/X12 flare on June 15, 1991. We undertook
an analysis of optical, radio, cosmic-ray, and other data in order to
identify the origin of the energetic particles producing these unusual
gamma-ray emissions. The analysis yields evidence that the gamma-rays
and other emissions, observed well after the impulsive phase of the
flare, appear to be initiated by prolonged nonstationary particle
acceleration directly during the late phase of the flare rather than by
a long-term trapping of energetic electrons and protons accelerated at
the onset of the flare. We argue that such an acceleration, including
the acceleration of protons up to GeV energies, can be caused by
a prolonged post-eruptive energy release following a coronal mass
ejection (CME), when the magnetic field above the active region,
strongly disturbed by the CME eruption, relaxes to its initial state
through magnetic reconnection in the coronal vertical current sheet.