BEGIN:VCALENDAR
VERSION:2.0
PRODID:icalendar-ruby
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/9713/7840847
DTSTART:20170427T090000Z
DTEND:20170427T100000Z
CLASS:PUBLIC
CREATED:20170426T105549Z
DESCRIPTION:Speaker: Clara Froment
LAST-MODIFIED:20260220T074006Z
LOCATION:Oslo (broadcasted at MPS)\, Room: seminar rooms D + E +F
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESPOS: European Solar Physics Online Seminar (Clara Froment)
URL;VALUE=URI:https://www.mps.mpg.de/events/9713/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/9830/7840847
DTSTART:20170427T090000Z
DTEND:20170427T100000Z
CLASS:PUBLIC
CREATED:20170503T083237Z
DESCRIPTION: The coupling of fast and Alfven magnetohydrodynamic (MHD) wave
 s is of fundamental interest in astrophysical plasmas. Under certain condi
 tions\, Alfven waves can be resonantly excited by fast mode waves\, result
 ing in a localised accumulation of energy in the plasma. In the solar comm
 unity this is often referred to as resonant absorption\, while in the magn
 etospheric community it's known as field line resonance. These processes h
 ave applications in coronal heating and in magnetospheric dynamics.Alfven 
 resonances are well understood in 1D and 2D\, but not so in 3D\, particula
 rly in non-Cartesian geometries. We present a theoretical way of understan
 ding the structure and temporal development of Alfven resonances in 3D\, w
 hich is corroborated by numerical simulations.\nSpeaker: Thomas Elsden
LAST-MODIFIED:20260220T074017Z
LOCATION:St Andrews (broadcasted at MPS)\, Room: Aquila + Bootes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESPOS - European Solar Physics Online Seminar: Theoretical F
 oundation of 3D Alfven Resonances: Time Dependent Solutions (T. Elsden)
URL;VALUE=URI:https://www.mps.mpg.de/events/9830/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/9989/7840847
DTSTART:20170518T090000Z
DTEND:20170518T100000Z
CLASS:PUBLIC
CREATED:20170512T123015Z
DESCRIPTION:Oscillations in sunspots have been extensively studied for seve
 ral decades. Most of the research conducted about sunspot oscillations has
  focussed around variations in Doppler velocities and intensities. Fewer o
 bservational studies have focused on variations of the magnetic field in t
 he photosphere\, reporting contradicting results. Recently\, variations in
  the magnetic field strength up to ∼200 G associated with running penumb
 ral waves (RPWs) in the chromosphere have been reported. In this study\, w
 e analyze variations in the magnetic field associated with umbral flashes 
 (UFs) and RPWs. We use spectropolarimetric observations recorded with CRis
 p Imaging SpectroPolarimeter (CRISP) mounted at Swedish 1-m Solar Telescop
 e (SST). We have obtained the photospheric and chromospheric magnetic fiel
 d of a sunspot by performing inversions of the Fe I 6301.5 &amp\; 6302.5 
 Å and the Ca II 8542 Å spectral lines\, respectively\, with the non-LTE 
 inversion code NICOLE. Our results do not show any significant variations 
 in the magnetic field strength in the photosphere. At chromospheric layers
 \, UFs indicate peak-to-peak variation of ∼275 G\, whereas in RPWs varia
 tions inthe amplitude of the magnetic field strength are reduced to ∼100
  G. Variations in the magnetic field in UFs and RPWs are correlated to the
  variations in the temperature. In the past\, many authors have suggested 
 that observed temporal variation in the photospheric magnetic field of sun
 spots could be an effect of changing opacity due to oscillations in thermo
 dynamical parameters. We analyzed changes in the geometrical height scale 
 of inferred magnetic field due to oscillations in the thermodynamical para
 meters. Our results suggest that the observed variations in the umbral and
  penumbral chromospheric magnetic field can not be explained only by opaci
 ty changes caused by these propagating shocks. Hence\, we conclude that th
 e observed magnetic field variations associated with UFs and RPWs are intr
 insic in nature.\nSpeaker: Jayant Joshi
LAST-MODIFIED:20260220T073955Z
LOCATION:Stockholm (broadcasted at MPS)\, Room: Hydra
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Magnetic field variations associated wit
 h umbral flashes and penumbral waves (J. Joshi)
URL;VALUE=URI:https://www.mps.mpg.de/events/9989/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/10907/7840847
DTSTART:20170831T090000Z
DTEND:20170831T100000Z
CLASS:PUBLIC
CREATED:20170828T083859Z
DESCRIPTION:Penumbral formation is a significant part of the flux emergence
  process. Despite the new advanced techniques in observations and simulati
 ons\, there are still processes that need to be clarified. In particular\,
  two aspects have been carefully investigated: whether there is a preferre
 d location where the penumbra starts to form and how the Evershed flow set
 s in. Recent observations by Schlichenmaier et al. (2010) show that the pe
 numbra forms in sectors and that the area between the two polarities preve
 nts the settlement of a stable penumbra. Using high-resolution spectropola
 rimetric data acquired by IBIS\, as well as HMI data\, we studied penumbra
 l formation in NOAA active region 11490. The results for the leading polar
 ity show that the onset of the classical Evershed flow occurs in a very sh
 ort time scale (1-3 hours) while the penumbra is forming. In addition\, we
  observed a clear evolution from redshift to blueshift in the penumbral fi
 laments in about 1 hour. Studying the formation of the first penumbral sec
 tor around the following pore\, we found that a stable penumbra forms in t
 he area facing the opposite polarity\, located below an AFS\, i.e. in a fl
 ux emergence region\, in contrast with the results of Schlichenmaier et al
 . (2010). Finally\, analysing six active regions\, we find no preferred lo
 cation for the formation of the first penumbral sector and we observe the 
 appearance of an inverse Evershed flow that changes sign when the penumbra
  appears.\nSpeaker: Mariarita Murabito
LAST-MODIFIED:20260220T073943Z
LOCATION:Catania (broadcasted at MPS)\, Room: Hydra
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Formation of the penumbra and start of t
 he Evershed Flow (M. Murabito)
URL;VALUE=URI:https://www.mps.mpg.de/events/10907/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/11017/7840847
DTSTART:20170914T090000Z
DTEND:20170914T100000Z
CLASS:PUBLIC
CREATED:20170908T070642Z
DESCRIPTION:Deep learning has emerged as a very powerful set of techniques 
 to extract relevant information from observations\, sometimes showing much
  better results that other set of finely tuned algorithms. In this contrib
 ution I present our efforts in applying deep learning to several problems 
 in Solar Physics\, from the estimation of horizontal velocities in the sol
 ar surface to fast image reconstruction.\nSpeaker: Andrés Asensio Ramos 
LAST-MODIFIED:20260220T073930Z
LOCATION:La Laguna\, Tenerifa (broadcasted at MPS\, Room: Aquila + Bottes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Deep Learning in Solar Physics (A. Asens
 io Ramos)
URL;VALUE=URI:https://www.mps.mpg.de/events/11017/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/11134/7840847
DTSTART:20170928T090000Z
DTEND:20170928T100000Z
CLASS:PUBLIC
CREATED:20170925T095624Z
DESCRIPTION:In this talk we will focus on diagnostic potential of the spect
 ral region around D lines of Sodium. We will first outline our approach to
  non-lte inversions\, and present a method for computation of response fun
 ctions in non-local thermodynamic equilibrium. We will then discuss the se
 nsitivity of Sodium D lines to the atmospheric parameters and present some
  example inversions of that spectral region.\nSpeaker: Ivan Milic
LAST-MODIFIED:20260220T073919Z
LOCATION:Goettingen\, Germany (boradcasted at MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Spectropolarimetric diagnostics using So
 dium D lines (I.Milic)
URL;VALUE=URI:https://www.mps.mpg.de/events/11134/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/11684/7840847
DTSTART:20171130T100000Z
DTEND:20171130T110000Z
CLASS:PUBLIC
CREATED:20171127T094433Z
DESCRIPTION: At the interface between the Sun's surface and million-degree 
 outer atmosphere or corona lies the chromosphere. At 10\,000K it is much c
 ooler than the corona\, but also many orders of magnitude denser. The chro
 mosphere processes all magneto-convective energy that drives the heating o
 f the million-degree outer atmosphere or corona\, and requires a heating r
 ate that is at least as large as that required for the corona. Yet many qu
 estions remain about what drives the chromospheric dynamics and energetics
  and how these are connected to the transition region and corona. The Inte
 rface Region Imaging Spectrograph (IRIS) is a NASA small explorer satellit
 e that was launched in 2013 to study how the Sun's magneto-convection powe
 rs the low solar atmosphere. I will review recent results from IRIS in whi
 ch observations and models are compared to study the role of small-scale m
 agnetic fields in the generation of violent jets and how these jets feed p
 lasma into the transition region and hot corona.\nSpeaker: Bart de Pontieu
LAST-MODIFIED:20260220T073856Z
LOCATION:Lockheed Martin Solar & Astrophysics Laboratory (broadcasted at MP
 S)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Interface Region Imaging Spectrograph vi
 ews of how the solar (B. de Pontieu) atmosphere is energized 
URL;VALUE=URI:https://www.mps.mpg.de/events/11684/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/11731/7840847
DTSTART:20171207T100000Z
DTEND:20171207T110000Z
CLASS:PUBLIC
CREATED:20171201T105641Z
DESCRIPTION:We study small-scale brightenings in Ca II 8542 Å line-core im
 ages to determine their nature and effect on localized heating and mass tr
 ansfer in active regions. To that end\, we analyzed high-resolution 2D spe
 ctroscopic observations of an active region acquired with the GREGOR Fabry
 -Perot Interferometer attached to the 1.5-meter GREGOR telescope onTenerif
 e\, Spain. The ground-based data were complemented with AIA and HMI images
  from SDO. Inversions of the spectra were carried out using NICOLE. We ide
 ntified three brightenings of sizes up to 2”x2”. We found evidence tha
 t the brightenings belonged to the footpoints of a microflare (MF). The pr
 operties of the observed brightenings disqualified the scenarios of Ellerm
 an bombs or IRIS bombs. However\, this MF shared some common properties wi
 th flaring active-region fibrils or flaring arch filaments (FAFs): (1) FAF
 s and MFs are both apparent in chromospheric and coronal layers according 
 to the AIA channels\, and (2) both show flaring arches with lifetimes of a
 bout 3.0-3.5 min and lengths of about 20”. Moreover\, the inversions rev
 ealed heating by 600 K at the footpoint location in the ambient chromosphe
 re during the impulsive phase. Bidirectional flows were present in the foo
 tpoints of the MF.\nSpeaker: Bart de Pontieu
LAST-MODIFIED:20260220T073846Z
LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) broadcasted on MP
 S\, Room: Aquila + Bootes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Ca II 8542 Å Brightenings Induced by a 
 Solar Microflare (C. Kuckein)
URL;VALUE=URI:https://www.mps.mpg.de/events/11731/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/11931/7840847
DTSTART:20180111T100000Z
DTEND:20180111T110000Z
CLASS:PUBLIC
CREATED:20180105T094214Z
DESCRIPTION: Surges are ubiquitous cool ejections in the solar atmosphere t
 hat often appear associated with other interesting phenomena such as UV bu
 rsts or coronal jets. Recent observations from the Interface Region Imagin
 g Spectrograph show that surges\, although traditionally related to chromo
 spheric lines such as H I 6563 Å or Ca II 8542 Å\, can exhibit enhanced 
 emission in Si IV and\, as a consequence\, lead to spectral profiles that 
 are brighter than for the average transition region. However\, a theoretic
 al explanation to understand that behaviour was missing. In this talk\, we
  analyse the response of the transition region to surge phenomena. To that
  end\, we carried out two 2.5D radiative-MHD numerical experiments using t
 he Bifrost code and including the non-equilibrium ionisation of silicon an
 d oxygen. In the experiments\, a cool and dense surge is obtained as a con
 sequence of magnetic flux emergence. We find that non-equilibrium is key t
 o understand why surges show enhanced emissivity in transition region line
 s. Studying the properties of emitting surge plasma\, we point out the imp
 ortant role of the optically thin radiative cooling and heat conduction fo
 r the non-equilibrium ionisation. Furthermore\, through the calculation of
  synthetic spectra of O IV\, we provide predictions for future observation
 s.\nSpeaker: Daniel Nóbrega-Siverio
LAST-MODIFIED:20260220T073835Z
LOCATION:Instituto de Astrofisica (IAC)\, La Laguna\, Tenerife\, Spain (bro
 adcasted on MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: On the Importance of Non-equilibrium Ion
 isation. Understanding (D. Nobrega Siverio) the Enhanced Emissivity of Si 
 IV and O IV in Solar Surges 
URL;VALUE=URI:https://www.mps.mpg.de/events/11931/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/12582/7840847
DTSTART:20180125T100000Z
DTEND:20180125T110000Z
CLASS:PUBLIC
CREATED:20180119T133337Z
DESCRIPTION: Sunspots are the longest known manifestation of solar activity
  and their magnetic nature has been known for more than a century. Despite
  this\, the boundary between umbrae and penumbrae\, the two fundamental su
 nspot regions\, has hitherto been solely defined by an intensity threshold
 . We now unveil the empirical law of the magnetic nature of the umbra-penu
 mbra boundary in stable sunspots: an invariant vertical component of the m
 agnetic field. We study the magnetic nature of umbra-penumbra boundaries i
 n sunspots of different sizes\, morphology\, evolutionary stage\, and phas
 e of the solar cycle. We use a sample of 88 scans of Hinode/SOT spectropol
 arimeter to infer the magnetic field properties at the umbral boundaries. 
 We define these boundaries by an intensity threshold and perform a statist
 ically analysis of the magnetic field properties at these boundaries. We s
 tatistically prove that the umbra-penumbra boundary in stable sunspots is 
 characterised by an invariant value of the vertical component of the magne
 tic field: The vertical component of the magnetic field strength does not 
 depend on the umbra size\, its morphology\, and phase of the solar cycle. 
 With statistical Bayesian inference\, we find that the vertical component 
 of the magnetic field strength is\, with 99\\% likelihood\, in the range o
 f 1849-1885 G with the most probable value of 1867 G. In contrast\, the ma
 gnetic field strength and inclination averaged along individual boundaries
  are found to be dependent on the umbral size: The larger the umbra\, the 
 stronger and more horizontal the magnetic field at its boundary is.\nSpeak
 er: Jan Jurčák 
LAST-MODIFIED:20260220T073826Z
LOCATION:Astronomical Institute of the Czech Academy of Sciences (broadcast
 ed at MPS)\, Room: Aquila + Bootes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: The Magnetic Nature of the Umbra-Penumbr
 a Boundary in Sunspots (J. Jurčák)
URL;VALUE=URI:https://www.mps.mpg.de/events/12582/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/12867/7840847
DTSTART:20180208T100000Z
DTEND:20180208T110000Z
CLASS:PUBLIC
CREATED:20180201T155656Z
DESCRIPTION: Ellerman bombs and UV bursts are transient brightenings that a
 re ubiquitously observed in the lower atmospheres of active and emerging f
 lux regions. While some Ellerman bombs display clear UV burst signatures\,
  not all have correlated UV signal or vice versa\, suggesting the underlyi
 ng atmospheric and magnetic properties may differ between events. As both 
 are believed to pinpoint sites of magnetic reconnection in reconfiguring f
 ields\, understanding their occurrence and detailed evolution may provide 
 helpful insights in the overall evolution of active regions. Here we prese
 nt results from observations and inversions of SST/CRISP and CHROMIS\, as 
 well as IRIS data of these transient events. At unprecedented spatial reso
 lution the CHROMIS Ca II H &amp\; K observations reveal dynamic fine struc
 ture suggesting a plasmoid-mediated reconnection process. We investigate s
 everal cases\, combining information from the Mg II h &amp\; k and Ca II 8
 542Å and H &amp\; K lines in order to infer the temperature stratificatio
 n and magnetic field configuration within which these events occur. I’ll
  address the difficulties of successfully inverting their Si IV profiles a
 nd will discuss our results in light of the current debate on the connecti
 on between UV bursts and Ellerman bombs\, their occurrence heights and in 
 particular the temperatures that they may (or may not) reach.\nSpeaker: Gr
 egal Vissers 
LAST-MODIFIED:20260220T073814Z
LOCATION:Institute for Solar Physics\, Stockholm University (broadcasted at
  MPS)\, Room: Cygnus + Draco
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Dissecting bombs and bursts: inversions 
 of reconnection events in SST-IRIS observations (G. Vissers) 
URL;VALUE=URI:https://www.mps.mpg.de/events/12867/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/12973/7840847
DTSTART:20180222T100000Z
DTEND:20180222T110000Z
CLASS:PUBLIC
CREATED:20180216T120936Z
DESCRIPTION: The magnetic field in the Sun undergoes a cyclic modulation wi
 th a reversal typically every 11 years due to a dynamo operating under the
  surface. Also\, other solar-like stars exhibit magnetic activity\, most o
 f them with much higher levels compared to the Sun. Some of these stars sh
 ow cyclic modulation of their activity similar to the Sun. The rotational 
 dependence of activity and cycle length suggests a common underlying dynam
 o mechanism.Here we present results of 3D MHD convective dynamo simulation
 s of slowly and rapidly rotating solar-type stars\, where the interplay be
 tween convection and rotation self-consistently drives a large-scale magne
 tic field. With the help of the test-field method\, we are able to measure
  the turbulent transport coefficients in these simulations and therefore g
 et insights about the dynamo mechanism operating in these simulations. It 
 allows us to derive a scaling of the cycle period with the relevant effect
 s of the dynamo.We discuss how magnetic helicity is a key quantity connect
 ing the stellar convection zone with the stellar surface and stellar coron
 ae. Magnetic helicity is produced in the convection zone of stars via a dy
 namo in the presence of convection and rotation. At the surface\, it plays
  an important role in the formation process of active regions. In the coro
 na\, it is believed to be essential for the release of energy leading to t
 he eruption of plasma via coronal mass ejections and is thought to play an
  important role in the heating process of the coronal plasma. Numerical si
 mulations of stellar convection zones and the solar corona allow us to inv
 estigate this process.\nSpeaker: Gregal Vissers 
LAST-MODIFIED:20260220T073750Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: What can numerical simulations tell us a
 bout the mechanism of solar and stellar activity? (J. Warnecke) 
URL;VALUE=URI:https://www.mps.mpg.de/events/12973/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/13239/7840847
DTSTART:20180222T100000Z
DTEND:20180222T110000Z
CLASS:PUBLIC
CREATED:20180305T130903Z
DESCRIPTION: Propagating slow magneto-acoustic waves are regularly observed
  in the solar corona\, particularly in sunspot related loop structures. Th
 ese waves exhibit rapid damping as they propagate along the loops. Several
  physical and geometrical effects were found to produce the observed decay
  in the wave amplitude. It has also been shown that the damping is frequen
 cy dependent. A majority of the observed characteristics have been attribu
 ted to damping by thermal conduction in the solar corona. Although it is b
 elieved that these waves originate in the photosphere\, their damping beha
 viour in the sub-coronal layers is relatively less studied. Using high spa
 tial and temporal resolution images of a sunspot\, we investigated propaga
 tion and damping characteristics of slow magnetoacoustic waves up to trans
 ition region heights. The major conclusions from this study will be discus
 sed in the talk which include: 1) The energy flux in slow waves estimated 
 from the relative amplitudes decays gradually right from the photosphere e
 ven when the oscillation amplitude is increasing. 2) The damping displayed
  by slow waves is frequency dependent well below coronal heights. 3) A spa
 tial comparison of power spectra across the umbra highlights enhancement o
 f high-frequency waves near the umbral center.\nSpeaker: Gregal Vissers 
LAST-MODIFIED:20260220T073803Z
LOCATION:Queen's University Belfast (broadcasted on MPS)\, Room: Aquila + B
 ootes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Frequency-dependent Damping of Slow Magn
 eto-acoustic Waves in Sunspots (K. Prasad ) 
URL;VALUE=URI:https://www.mps.mpg.de/events/13239/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/13317/7840847
DTSTART:20180322T100000Z
DTEND:20180322T110000Z
CLASS:PUBLIC
CREATED:20180316T141728Z
DESCRIPTION: Ellerman bombs and UV bursts are transient brightenings that a
 re ubiquitously observed in the lower atmospheres of active and emerging f
 lux regions. While some Ellerman bombs display clear UV burst signatures\,
  not all have correlated UV signal or vice versa\, suggesting the underlyi
 ng atmospheric and magnetic properties may differ between events. As both 
 are believed to pinpoint sites of magnetic reconnection in reconfiguring f
 ields\, understanding their occurrence and detailed evolution may provide 
 helpful insights in the overall evolution of active regions. Here we prese
 nt results from observations and inversions of SST/CRISP and CHROMIS\, as 
 well as IRIS data of these transient events. At unprecedented spatial reso
 lution the CHROMIS Ca II H &amp\; K observations reveal dynamic fine struc
 ture suggesting a plasmoid-mediated reconnection process. We investigate s
 everal cases\, combining information from the Mg II h &amp\; k and Ca II 8
 542Å and H &amp\; K lines in order to infer the temperature stratificatio
 n and magnetic field configuration within which these events occur. I’ll
  address the difficulties of successfully inverting their Si IV profiles a
 nd will discuss our results in light of the current debate on the connecti
 on between UV bursts and Ellerman bombs\, their occurrence heights and in 
 particular the temperatures that they may (or may not) reach.\nSpeaker: Pe
 tros Syntelis
LAST-MODIFIED:20260220T073735Z
LOCATION:St. Andrews University\, Scotland\, UK (broadcasted at MPS)\, Room
 : Aquila + Bootes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Recurrent CME-like Eruptions in Flux Eme
 rgence Simulations (P. Syntelis)
URL;VALUE=URI:https://www.mps.mpg.de/events/13317/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/13639/7840847
DTSTART:20180412T090000Z
DTEND:20180412T100000Z
CLASS:PUBLIC
CREATED:20180411T081029Z
DESCRIPTION: Long-period intensity pulsations have been recently detected i
 n coronal loops with EUV images of both SoHO/EIT (Auchère et al.\, 2014) 
 and SDO/AIA (Froment et al.\, 2015). These pulsations have been interprete
 d as resulting from thermal non-equilibrium (TNE)\, thus providing a signa
 ture of a highly-stratified and quasi-constant heating at the loops footpo
 ints (Froment et al.\, 2017\; Auchère et al.\, 2016). Depending on the ad
 equacy between the geometry of the loop and the characteristics of the hea
 ting\, this can result in either complete (down to chromospheric temperatu
 res) or incomplete (&gt\; 1 MK) condensation and evaporation cycles\, that
  are responsible for the observed intensity pulsations. Using 1D hydrodyna
 mic simulations\, Froment et al. (2017\, 2018) were able to reproduce the 
 observed pulsations\, with incomplete condensation for the active region s
 tudied in their previous paper. The simulations also predict periodic plas
 ma flows along the loops footpoints\, with velocities up to 40 km/s. We tr
 y to detect these flows by using time series of spatially resolved spectra
  from the EUV spectrometer Hinode/EIS. We systematically search for EIS da
 tasets that correspond to the observation of pulsation events among the 30
 00+ that were detected in AIA data\, between 2010 and 2016. For the 11 dat
 asets that are found\, we derive series of Doppler velocity maps\, which a
 llows us to track the evolution of the plasma velocity in the loop over se
 veral pulsation periods. We then compare these data to the results of prev
 ious simulations and observations. We detect the signature of flows along 
 some loops that have velocity patterns consistent with the predictions fro
 m the simulations. However\, the expected pulsations in velocity cannot be
  identified in any of the datasets that we analysed\, either due to insuff
 icient temporal resolution\, or to line of sight ambiguities combined with
  low signal to noise.\nSpeaker: Gabriel Pelouze 
LAST-MODIFIED:20260220T073723Z
LOCATION:Institut d'Astrophysique Spatiale (broadcasted at MPS)\, Room: Aud
 itorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Search for predicted periodic flows in l
 oops undergoing thermal non-equilibrium (G. Pelouze) 
URL;VALUE=URI:https://www.mps.mpg.de/events/13639/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/13642/7840847
DTSTART:20180419T090000Z
DTEND:20180419T100000Z
CLASS:PUBLIC
CREATED:20180411T082054Z
DESCRIPTION: A giant solar filament was visible on the solar surface betwee
 n 8-23 November 2011. The filament stretched over more than half a solar d
 iameter. Multi-wavelength data from the SDO instrument AIA (171\, 193\, 30
 4\, and 211 Å) were used to examine counter-streaming flows within the sp
 ine of the filament. H-alpha images from the Kanzelhöhe Solar Observatory
  provided context information. We applied local correlation tracking (LCT)
  to a two-hour AIA time series from 16 November 2011 to derive horizontal 
 flow velocities of the filament. To enhance the contrast of the AIA images
 \, we employed noise adaptive fuzzy equalization (NAFE)\, allowing us to i
 dentify and quantify counter-streaming flows in the filament. We detected 
 counter-streaming flows in the filament\, visible in the time-lapse movies
  of all the examined AIA wavelength bands. Using time-lapse movies we foun
 d that these persistent flows lasted for at least two hours. Furthermore\,
  by applying LCT to the images we clearly determined counter-streaming flo
 ws in time series of 171 Å and 193 Å images. In the 304 Å wavelength ba
 nd we found only minor indications for counter-streaming flows with LCT\, 
 while in the 211 Å wavelength band the counter-streaming flows are not de
 tectable. The average horizontal flows reach mean flow speeds of 0.5 km/s.
  The highest horizontal flow speeds are identified in the 171 Å band with
  flow speeds of up to 2.5 km/s. The results are averaged over a time serie
 s of 90 min. Because the LCT sampling window has a finite width\, spatial 
 degradation cannot be avoided\, leading to lower estimates of the flow vel
 ocities as compared to feature tracking or Doppler measurements. The count
 er-streaming flows cover about 15-20% of the whole area of the EUV filamen
 t channel and are located in the central part of the spine. In conclusion\
 , we confirm counter-streaming flows are omnipresent also in giant quiet-S
 un filaments.\nSpeaker: Andrea Dierke
LAST-MODIFIED:20260220T073710Z
LOCATION:Leibniz Institute for Astrophysics Potsdam (AIP) broadcasted on MP
 S\, Room: Aquila\, Bootes\, Cygnus
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Counter-streaming Flows of a Giant Solar
  Filament as Observed in the Extreme Ultraviolet (A. Dierke)
URL;VALUE=URI:https://www.mps.mpg.de/events/13642/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/13935/7840847
DTSTART:20180503T090000Z
DTEND:20180503T100000Z
CLASS:PUBLIC
CREATED:20180502T114112Z
DESCRIPTION: We report multi-wavelength ultraviolet observations taken with
  the IRIS satellite\, concerning the emergence phase in the upper chromosp
 here and transition region of an emerging flux region (EFR) embedded in th
 e unipolar plage of active region NOAA 12529. IRIS data are complemented b
 y full-disk\, simultaneous observations of the Solar Dynamics Observatory 
 satellite\, relevant to the photosphere and the corona. The photospheric c
 onfiguration of the EFR is also analysed by measurements taken with the sp
 ectropolarimeter onboard the Hinode satellite\, when the EFR was fully dev
 eloped. Recurrent intense brightenings that resemble UV bursts\, with coun
 terparts in all coronal passbands\, are identified at the edges of the EFR
 . Jet activity is also found at chromospheric and coronal levels\, near th
 e observed brightness enhancement sites. Analysis of the IRIS line profile
 s reveals heating of dense plasma in the low solar atmosphere and the driv
 ing of bi-directional\, high-velocity flows with speeds up to 100 km/s at 
 the same locations. Comparing these signatures with previous observations 
 and numerical models\, we suggest evidence of several long-lasting\, small
 -scale magnetic reconnection episodes between the emerging bipole and the 
 ambient field. This process leads to the cancellation of a pre-existing ph
 otospheric flux concentration of the plage with the opposite polarity flux
  patch of the EFR. Moreover\, the reconnection appears to occur higher in 
 the atmosphere than usually found in UV bursts\, explaining the observed c
 oronal counterparts.\nSpeaker: Salvo Guglielmino 
LAST-MODIFIED:20260220T073651Z
LOCATION:Osservatorio Astrofisico di Catania (broadcasted at MPS)\, Room: A
 uditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Interactions between pre-existing and em
 erging magnetic flux systems observed with IRIS (S. Guglielmino)
URL;VALUE=URI:https://www.mps.mpg.de/events/13935/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/13942/7840847
DTSTART:20180614T090000Z
DTEND:20180614T100000Z
CLASS:PUBLIC
CREATED:20180503T073330Z
DESCRIPTION:We present an overview of K2 short cadence observations for 32 
 M dwarfswhich have spectral types between M0-L1. All of the stars in our s
 ampleshowed flares with the most energetic reaching 3x10^34 ergs. As previ
 ousstudies have found\, we find rapidly rotating stars tend to show morefl
 ares\, with evidence for a decline in activity in stars with rotationperio
 ds longer than approximately 10 days. We determined the rotationalphase of
  each flare and performed a simple statistical test on oursample to determ
 ine whether the phase distribution of the flares israndom or if there is a
  preference for phase. We find none show apreference for the rotational ph
 ase of the flares. If the analogybetween the physics of solar and stellar 
 flares holds and these eventsoccur from active regions which typically hos
 t spots\, then you wouldexpect to see more flares during the rotation mini
 mum where the starspotis most visible. However\, this is not the case with
  our sample and infact all of our stars show flares at all rotational phas
 es\, suggestingthese flares are not all originating from one dominant star
 spot on thesurface of the stars. We outline three scenarios which could ex
 plain thelack of a correlation between the number of flares and the stella
 rrotation phase.\nSpeaker: Lauren Doyle
LAST-MODIFIED:20260220T073638Z
LOCATION:Armagh Observatory\, Armagh\, UK (broadcasted at MPS)\, Room: Audi
 torium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Searching for the Origin of Flares in M 
 dwarfs (L. Doyle)
URL;VALUE=URI:https://www.mps.mpg.de/events/13942/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/15164/7840847
DTSTART:20180906T090000Z
DTEND:20180906T100000Z
CLASS:PUBLIC
CREATED:20180904T073414Z
DESCRIPTION:The strong enhancement of the ultraviolet emission during solar
  flares is usually taken as an indication of plasma heating in the low sol
 ar atmosphere caused by the deposition of the energy released during these
  events. Images taken with broadband ultraviolet filters by the Transition
  Region and Coronal Explorer (TRACE) and Atmospheric Imaging Assembly (AIA
  1600 and 1700 Å) have revealed the morphology and evolution of flare rib
 bons in great detail. However\, the spectral content of these images is st
 ill largely unknown. Without the knowledge of the spectral contribution to
  these UV filters\, the use of these rich imaging datasets is severely lim
 ited. Aiming to solve this issue\, we estimate the spectral contributions 
 of the AIA UV flare and plage images using high-resolution spectra in the 
 range 1300 to 1900 Å from the Skylab NRL SO82B spectrograph. We find that
  the flare excess emission in AIA 1600 Å is composed of the C IV 1550 Å 
 doublet (26%)\, Si I continua (20%)\, with smaller contributions from many
  other chromospheric lines such as C I 1561 and 1656 Å multiplets\, He II
  1640 Å\, Si II 1526 and 1533 Å. For the AIA 1700 Å band\, C I 1656 Å 
 multiplet is the main contributor (38%)\, followed by He II 1640 (17%)\, a
 nd accompanied by a multitude of other chromospheric lines\, with minimal 
 contribution from the continuum. Our results can be generalised to state t
 hat the AIA UV flare excess emission is of chromospheric origin\, while pl
 age emission is dominated by photospheric continuum emission in both chann
 els.\nSpeaker: Paulo Simões
LAST-MODIFIED:20260220T073627Z
LOCATION:University of Glasgow (broadcasted at MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: The spectral content of SDO/AIA 1600 and
  1700 Å filters from flare and plage observations (P. Simões)
URL;VALUE=URI:https://www.mps.mpg.de/events/15164/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/15354/7840847
DTSTART:20180920T090000Z
DTEND:20180920T100000Z
CLASS:PUBLIC
CREATED:20180914T085647Z
DESCRIPTION: We present preliminary results derived from the analysis of sp
 ectropolarimetric measurements of active region AR12546\, which represents
  one of the largest sunspots to have emerged onto the solar surface over t
 he last 20 years. The region was observed with full-Stokes scans of the Fe
  I 617.3 nm and Ca II 854.2 nm lines with the Interferometric BIdimensiona
 l Spectrometer (IBIS) instrument at the Dunn Solar Telescope over an uncom
 mon\, extremely long time interval exceeding three hours. We show prelimin
 ary results from the phase lag analysis of different quantities and discus
 s the results in terms of the literature on the subject and MHD wave propa
 gation theory.\nSpeaker: Marco Stangalini
LAST-MODIFIED:20260220T073614Z
LOCATION:University of Glasgow (broadcasted at MPS)\, Room: Aquila + Bootes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Multi-height spectropolarimetric study o
 f MHD waves in a big sunspot observed with IBIS (M. Stangalini)
URL;VALUE=URI:https://www.mps.mpg.de/events/15354/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/15547/7840847
DTSTART:20181004T090000Z
DTEND:20181004T100000Z
CLASS:PUBLIC
CREATED:20180927T133431Z
DESCRIPTION:While surface waves propagating at tangential discontinuities h
 ave been studied in great detail\, few studies have been dedicated to the 
 investigation of the nature of waves at contact discontinuities\, i.e. pla
 sma discontinuity\, where the background magnetic field crosses the interf
 ace between two media. In this talk\, I will show that by introducing magn
 etic field inclination\, the frequency of waves is rendered complex\, wher
 e the imaginary part describes wave attenuation\, due to lateral energy le
 akage. We investigate the eigenvalue and initial value problem and determi
 ne the conditions of transition from contact with the tangential discontin
 uity. Finally\, I will present an investigation into the effect of magneti
 c field inclination on magnetic Rayleigh-Taylor instability.\nSpeaker: Ele
 anor Vickers 
LAST-MODIFIED:20260220T073602Z
LOCATION:Plasma Dynamics Group\, University of Sheffield (broadcasted at MP
 S)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Surface waves and instabilities in the p
 resence of an inclined magnetic field (E. Vickers)
URL;VALUE=URI:https://www.mps.mpg.de/events/15547/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/16081/7840847
DTSTART:20181115T100000Z
DTEND:20181115T110000Z
CLASS:PUBLIC
CREATED:20181112T095812Z
DESCRIPTION:Are solar MHD waveguides symmetric? It is convenient to assume 
 that they are. The solar physics community is familiar with the traditiona
 l notion of sausage and kink waves\, which propagate along waveguides in t
 he solar atmosphere that we assume are symmetric. In this talk\, we drop t
 his assumption and motivate the study of MHD wave propagation in asymmetri
 c waveguides from theoretical and observational viewpoints. We discuss the
  implications that asymmetric waveguides have for mode identification\, hi
 ghlighting the observational ambiguity between waves in symmetric and asym
 metric waveguides\, which becomes a crucial consideration when implementin
 g magneto-seismology diagnostics. We present a novel technique for solar m
 agneto-seismology that utilises the observed asymmetry of MHD waves to dia
 gnose background parameters of the solar atmosphere that are difficult to 
 measure using traditional methods. We present a preliminary application of
  this technique to chromospheric fibrils as a proof-of-concept and discuss
  the potential further application to prominences\, elongated magnetic bri
 ght points\, and sunspot light walls.\nSpeaker: Matthew Allcock
LAST-MODIFIED:20260220T073544Z
LOCATION:Plasma Dynamics Group\, University of Sheffield (broadcasted at MP
 S)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Asymmetric Solar Waveguides: Theory and 
 Observations (M. Allcock)
URL;VALUE=URI:https://www.mps.mpg.de/events/16081/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/16502/7840847
DTSTART:20181129T100000Z
DTEND:20181129T110000Z
CLASS:PUBLIC
CREATED:20181123T075818Z
DESCRIPTION:The emergence of magnetic flux through the photosphere and into
  the outer solar atmosphere produces\, amongst many other phenomena\, the 
 appearance of Ellerman bombs (EBs) in the photosphere. EBs are observed in
  the wings of Hα and are highly likely to be due to reconnection in the p
 hotosphere\, below the chromospheric canopy. But signs of the reconnection
  process are also observed in several other spectral lines\, typical of th
 e chromosphere or transition region. An example are the UV bursts observed
  in the transition region lines of Si IV. In this work we analyse high-cad
 ence coordinated observations between the Swedish 1-m Solar Telescope (SST
 ) and the IRIS spacecraft in order to study the possible relationship betw
 een reconnection events at different layers in the atmosphere\, and in par
 ticular\, the timing history between them. High-cadence\, high-resolution 
 Hα images from the SST provide us with the positions\, timings and trajec
 tories of Ellerman bombs in an emerging flux region. Simultaneous co-align
 ed IRIS slit-jaw images at 2796Å\, 1400Å and 1330Å and detailed Mg II a
 nd Si IV spectra from the fast spectrograph raster allow us to study the p
 ossible chromospheric/transition region counterparts of those photospheric
  Ellerman bombs. Our main goal is to study whether there is a temporal and
  spatial relationship between the appearance of an EB and the appearance o
 f a UV burst.\nSpeaker: Ada Ortiz
LAST-MODIFIED:20260220T073529Z
LOCATION:University of Oslo Institute of Theoretical Astrophysics (broadcas
 ted at MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Ellerman bombs and UV bursts: reconnecti
 on at different atmospheric layers? (A. Ortiz)
URL;VALUE=URI:https://www.mps.mpg.de/events/16502/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/16967/7840847
DTSTART:20181213T100000Z
DTEND:20181213T110000Z
CLASS:PUBLIC
CREATED:20181207T082042Z
DESCRIPTION:Are some parts of the Interplanetary Magnetic Field’s (IMF) n
 eutral line more flare energetic than others? What are Hale Sector Boundar
 ies (HSBs) and are they connected with flares? Do they have anything to do
  with Active Longitudes? In this work\, I will discuss how RHESSI flares a
 re associated with structures in the solar magnetic field termed as HSBs. 
 If you think of the large-scale domains of different polarity that the IMF
  is formed of\, they the parts of the boundary between them\, that have th
 e same polarity change as the sunspots back at the Sun. As the polarity of
  sunspots follows Hale’s law\, the HSB of a particular polarity change w
 ill only occur in one hemisphere per cycle\, and then alternate in the nex
 t cycle. It has previously been shown that HSBs coincide with stronger mag
 netic fields and more frequent flare occurrence (Dittmer 1975\, Svalgaard 
 &amp\; Wilcox 1976\, Svalgaard et al. 2011). I will explain how we extende
 d this work through solar cycles 23 and 24 using RHESSI flare locations fr
 om2002 to 2016. We compared these flares to the HSBs determined using two 
 different methods. One uses the polarity change at the Earth to estimate w
 hen the HSB was at solar central meridian and the other uses Potential Fie
 ld Source Surface (PFSS) extrapolations to identify the HSB for all times.
  We found that for both Cycle 23 and 24 more than 40% of non-limb flares w
 ere located near a HSB\, a correlation that varies with cycle phase and he
 misphere. I will describe how this evolves with time and the potential of 
 these approaches for assisting flare forecasting. We then used the locatio
 ns of HSBs calculated with the first method\,using Earth-based data\, to a
  Carrington rotation system and comparedthem with the migration paths of A
 ctive Longitudes as show in Gyenge et al. (2016). We found that there are 
 times where they overlap\, but that is not happening in a consistent manne
 r. They often move at different rates relative to each other (and the Carr
 ington solar rotation rate) and these vary over each Cycle.\nSpeaker: Kons
 tantina Loumou 
LAST-MODIFIED:20260220T073512Z
LOCATION:University of Glasgow (broadcasted at MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: The association of RHESSI flares to the 
 Hale Sector Boundary and Active Longitudes (K. Loumou)
URL;VALUE=URI:https://www.mps.mpg.de/events/16967/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/17789/7840847
DTSTART:20181228T100000Z
DTEND:20181228T110000Z
CLASS:PUBLIC
CREATED:20190225T080843Z
DESCRIPTION: The Wilson depression is the difference in geometric height of
  the layer of unit continuum optical depth between the sunspot umbra and t
 he quiet Sun. Measuring the Wilson depression is important for understandi
 ng the geometry of sunspots. Current methods suffer from systematic effect
 s or need to make assumptions on the geometry of the magnetic field. This 
 leads to large systematic uncertainties of the derived Wilson depressions.
  Here we present a method for deriving the Wilson depression that only req
 uires the information about the magnetic field that are accessible by spec
 tropolarimetry and that does not rely on assumptions on the geometry of su
 nspots or on its magnetic field. Our method is based on minimizing the div
 ergence of the magnetic field vector derived from spectropolarimetric obse
 rvations. We focus on large spatial scales only in order to reduce the num
 ber of free parameters. We test the performance of our method using synthe
 tic Hinode data derived from two sunspot simulations. We find that the max
 imum and the umbral averaged Wilson depression for both spots determined w
 ith our method typically lies within 100 km of the true value obtained fro
 m the simulations. In addition\, we apply the method to spots from the Hin
 ode sunspot database at MPS. The derived Wilson depressions (500-700 km) a
 re consistent with results typically obtained from the Wilson effect. In o
 ur sample\, larger spots with a stronger magnetic field exhibit a higher W
 ilson depression than smaller spots.\nSpeaker: Björn Löptien
LAST-MODIFIED:20260220T073500Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: A new method for measuring the Wilson de
 pression of sunspots (Björn Löptien)
URL;VALUE=URI:https://www.mps.mpg.de/events/17789/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/17478/7840847
DTSTART:20190131T100000Z
DTEND:20190131T110000Z
CLASS:PUBLIC
CREATED:20190123T092501Z
DESCRIPTION:Solar observations offer both a rich interdisciplinary laborato
 ry on fundamental astrophysics and precious tools for Space Weather applic
 ations. The involved plasma processes determine a complex radio emission p
 icture that could be efficiently explored through single-dish imaging at h
 igh frequencies. In particular\, mapping the brightness temperature of the
  free-free radio emission in the centimetre and millimetre range is an eff
 ective tool to characterise the vertical structure of the solar atmosphere
 .In this presentation I disclose the continuum imaging of chromosphere and
  corona in K-band (18-26.5 GHz) performed with the 32-m diameter Medicina 
 Radio Telescope and the 64-m diameter Sardinia Radio Telescope (SRT)\, as 
 a first scientific demonstration test for the potentialities of Italian si
 ngle-dish antennas in this field. These observations proved that the anten
 nas and K-band receivers are stable during solar pointing and could provid
 e full mapping of the solar disk in about 1 hour exposure using state-of-t
 he-art imaging techniques. This study will be useful for the assessment of
  observation parameters aiming at studying in detail the chromospheric bri
 ghtness temperature of the quiet Sun\, the solar flares and the sunspots\;
  in perspective\, a contribution will be provided to Space Weather monitor
 ing networks and forecast\, filling different gaps that presently exist in
  the worldwide observing scenario.\nSpeaker: Giulia Murtas
LAST-MODIFIED:20260220T073431Z
LOCATION:University of Exeter (broadcasted at MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Imaging of the solar atmosphere in the c
 entimetre-millimeter band through Single-Dish observations (G. Murtas)
URL;VALUE=URI:https://www.mps.mpg.de/events/17478/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/17646/7840847
DTSTART:20190214T100000Z
DTEND:20190214T110000Z
CLASS:PUBLIC
CREATED:20190207T153041Z
DESCRIPTION: We present high spatial resolution narrow-band images in three
  different chromospheric spectral lines\, including Ca II K with the new C
 HROMospheric Imaging Spectrometer installed at the Swedish 1-m Solar Teles
 cope. These observations feature a unipolar region enclosed in a supergran
 ular cell\, and located 68º off the disk-centre. The observed cell exhibi
 ts a radial arrangement of the fibrils which recalls of a chromospheric ro
 sette. However\, in this case\, the convergence point of the fibrils is lo
 cated at the very centre of the supergranular cell. Our study aims to show
  how the chromosphere appears in this peculiar region and retrieve its mag
 netic field and velocity distribution. In the centre of the cell\, we meas
 ured a significant blue-shift in the Ca II K nominal line core associated 
 to an intensity enhancement. We interpreted it as the product of a strong 
 velocity gradient along the line of sight. In this talk\, we will discuss 
 the techniques employed to obtain magnetic field maps so close to the limb
  and suggest a possible configuration that takes into account also the mea
 sured velocity within the unipolar region.\nSpeaker: Carolina Robustini 
LAST-MODIFIED:20260220T073419Z
LOCATION:Institute for Solar Physics\, Stockholm University (broadcasted at
  MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Chromospheric observations and magnetic 
 configuration of a supergranular structure (Carolina Robustini) 
URL;VALUE=URI:https://www.mps.mpg.de/events/17646/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/17972/7840847
DTSTART:20190314T100000Z
DTEND:20190314T110000Z
CLASS:PUBLIC
CREATED:20190308T124330Z
DESCRIPTION:The ubiquitous presence of small magnetic elements in the Quiet
  Sun represents a prominent coupling between the photosphere and the upper
  layers of the Sun’s atmosphere. Small magnetic element tracking has bee
 n widely used to study the transport and diffusion of the magnetic field o
 n the solar photosphere. From the analysis of the displacement spectrum of
  these tracers\, it has been recently agreed that a regime of super-diffus
 ivity dominates the solar surface. In this talk we will focus on the analy
 sis of the bipolar magnetic pairs in the solar photosphere and their diffu
 sion properties\, using a 25-h dataset from the HINODE satellite. Interest
 ingly\, the displacement spectrum for bipolar couples behaves similarly to
  the case where all magnetic pairs are considered. We also measure\, from 
 the same dataset\, the magnetic emergence rate of the bipolar magnetic pai
 rs and we interpret them as the magnetic footpoints of emerging magnetic l
 oops. The measured magnetic emergence rate is used to constrain a simplifi
 ed model that mimics the advection on the solar surface and evolves the po
 sition of a great number of loops\, taking into account emergence\, reconn
 ection and cancellation events. In particular we compute the energy releas
 ed by the reconnection between different magnetic loops in the nano-flares
  energy range. Our model gives a quantitative estimate of the energy relea
 sed by the reconfiguration of the magnetic loops in a quiet Sun area as a 
 function of height in the solar atmosphere\, from hundreds of Km above the
  photosphere up to the corona\, suggesting that an efficiency of ~10% in t
 he energy deposition might sustain the million degree corona.\nSpeaker: Lu
 ca Giovannelli
LAST-MODIFIED:20260220T073408Z
LOCATION:University of Rome Tor Vergata (broadcasted at MPS)\, Room: Aquila
  + Bootes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Emerging bipolar magnetic pairs in the s
 olar photosphere: diffusion properties and contribution to the coronal hea
 ting (Luca Giovannelli)
URL;VALUE=URI:https://www.mps.mpg.de/events/17972/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/18135/7840847
DTSTART:20190328T100000Z
DTEND:20190328T110000Z
CLASS:PUBLIC
CREATED:20190321T164208Z
DESCRIPTION:To understand the links between the distribution of the promine
 nce plasma\, the configuration of its magnetic field and the observations 
 of prominence/filament fine structures obtained in UV/EUV\, optical and ra
 dio domains from various vantage points\, we need complex 3D prominence mo
 dels. We have developed two such models which combine 3D magnetic field co
 nfigurations of an entire prominence with a detailed description of the pr
 ominence plasma distributed along hundreds of fine structures. The first 3
 D Whole-Prominence Fine Structure (WPFS) model\, developed by Gunár &amp\
 ; Mackay (2015)\, uses a magnetic field configuration obtained from non-li
 near force-free field simulations of Mackay &amp\; van Ballegooijen (2009)
 . The second WPFS model was developed by Gunár\, Dudík\, Aulanier\, Schm
 ieder &amp\; Heinzel (2018). The model employs a magnetic field configurat
 ion of a polar crown prominence based on the linear force-free field model
 ling approach designed by Aulanier &amp\; Démoulin (1998) which allows us
  to calculate linear magneto-hydrostatic extrapolations from photospheric 
 flux distributions. The prominence plasma in both models is located in mag
 netic dips that occur naturally in the predominantly horizontal prominence
  magnetic field. This plasma has a realistic distribution of the density a
 nd temperature\, including the prominence-corona transition region. The mo
 dels thus provide comprehensive information about the 3D distribution of t
 he prominence plasma and magnetic field which can be consistently studied 
 both as a prominence on the limb and as a filament on the disk. These mode
 ls can be visualized for example in the H-alpha spectral line. Together wi
 th the models\, we will present some of their capabilities which allow us 
 to study the evolution of prominences/filaments or to analyze the true and
  apparent shapes and motions of the prominence fine structures.\nSpeaker: 
 Stanislav Gunár 
LAST-MODIFIED:20260220T073355Z
LOCATION:Astronomical Institute of the Czech Academy of Sciences (broadcast
 ed at MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: 3D Whole-Prominence Fine Structure model
 s: the current state of the affairs (Stanislav Gunár)
URL;VALUE=URI:https://www.mps.mpg.de/events/18135/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/18257/7840847
DTSTART:20190411T090000Z
DTEND:20190411T100000Z
CLASS:PUBLIC
CREATED:20190405T094526Z
DESCRIPTION:The Astronomical Observatory of the Coimbra University has a co
 llection of solar observations on a daily basis\, since 1926. We obtain re
 gular observations of the full solar disk using a classical spectroheliogr
 aph\, in the spectral lines of Ca II and Halpha (this one only after 1989)
 . Until 2007 the acquisition was based on photographic plates and films. T
 his data is digitized and public. Since then\, a 12-bit CCD camera is oper
 ational. Nowadays\, the local weather conditions allows observations in mo
 re than 300 days/year. This data is\, particularly\, suitable for solar cy
 cle studies. In this talk\, we briefly present a history of these observat
 ions\; we discuss recent results using the data\; and we present some pers
 pectives for the near future. The ubiquitous presence of small magnetic el
 ements in the Quiet Sun represents a prominent coupling between the photos
 phere and the upper layers of the Sun’s atmosphere. Small magnetic eleme
 nt tracking has been widely used to study the transport and diffusion of t
 he magnetic field on the solar photosphere. From the analysis of the displ
 acement spectrum of these tracers\, it has been recently agreed that a reg
 ime of super-diffusivity dominates the solar surface. In this talk we will
  focus on the analysis of the bipolar magnetic pairs in the solar photosph
 ere and their diffusion properties\, using a 25-h dataset from the HINODE 
 satellite. Interestingly\, the displacement spectrum for bipolar couples b
 ehaves similarly to the case where all magnetic pairs are considered. We a
 lso measure\, from the same dataset\, the magnetic emergence rate of the b
 ipolar magnetic pairs and we interpret them as the magnetic footpoints of 
 emerging magnetic loops. The measured magnetic emergence rate is used to c
 onstrain a simplified model that mimics the advection on the solar surface
  and evolves the position of a great number of loops\, taking into account
  emergence\, reconnection and cancellation events. In particular we comput
 e the energy released by the reconnection between different magnetic loops
  in the nano-flares energy range. Our model gives a quantitative estimate 
 of the energy released by the reconfiguration of the magnetic loops in a q
 uiet Sun area as a function of height in the solar atmosphere\, from hundr
 eds of Km above the photosphere up to the corona\, suggesting that an effi
 ciency of ~10% in the energy deposition might sustain the million degree c
 orona.\nSpeaker: João Fernandes 
LAST-MODIFIED:20260220T073337Z
LOCATION:University of Coimbra\, Portugal (broadcasted at MPS)\, Room: Audi
 torium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: The Sun from Coimbra: history\, recent r
 esults and perspectives (João Fernandes)
URL;VALUE=URI:https://www.mps.mpg.de/events/18257/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/18348/7840847
DTSTART:20190425T090000Z
DTEND:20190425T100000Z
CLASS:PUBLIC
CREATED:20190418T065732Z
DESCRIPTION:We carry out multi-dimensional kinematic analysis of a prominen
 ce eruption in order to characterise the role of eruptive ideal-MHD instab
 ilities. Using SDO/AIA and STEREO/EUVI-A we reconstruct the leading edge o
 f the prominence in 3D\, as observed between 26-Feb-2013 20:30:00 UT and 2
 7-Feb-2013 05:45:00 UT. We use a novel semi-automated\, dual\, edge detect
 ion method to precisely detect the leading edge and create height-time pro
 files from SDO/AIA image sequences in He II 30.4 nm\, to analyse the kinem
 atics of erupting plasma along radial slits intersecting the leading edge 
 coordinates. Constraining the power index parameter of fitted functions ch
 aracterizing the linear and non-linear phases of the eruption\, we investi
 gate a set of fits of the eruption profile across all slits and identify t
 he best fit in order to compare different eruption mechanisms. We also par
 ameterise the onset time of the acceleration phase in order to confine the
  start time of the torus instability. For the first time\, 3D kinematic an
 alysis has identified a significant delay in the onset time of the acceler
 ation phase together with a corresponding critical height at which acceler
 ation starts to occur\, as a function of position along the leading edge\,
  which is in remarkable agreement with the determination of the critical h
 eight according to the decay index governing the torus instability.\nSpeak
 er: Thomas Rees-Crockford 
LAST-MODIFIED:20260220T073324Z
LOCATION:Northumbria University (broadcasted at MPS)\, Room: Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: 2D and 3D Kinematic Analysis of an Ideal
 -MHD Prominence Eruption (Thomas Rees-Crockford)
URL;VALUE=URI:https://www.mps.mpg.de/events/18348/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/18582/7840847
DTSTART:20190509T090000Z
DTEND:20190509T100000Z
CLASS:PUBLIC
CREATED:20190502T134108Z
DESCRIPTION: Since the work of Carlin et al. (2012)\, more studies have inv
 estigated\, with the help of MHD models of the solar chromosphere\, the be
 havior of scattering linear polarization (LP) in presence of macroscopic m
 otions and weak magnetic fields. The results of the spatio-temporal simula
 tions revealed a variable spectral morphology in the polarization of chrom
 ospheric lines\, as well as modulations of LP amplitude that affect Hanle 
 diagnosis\, and also several situations with clear potential for diagnosin
 g solar and stellar atmospheres. While much of these results resorts in th
 e dynamic variations of radiation field anisotropy along the (also dynamic
 ) formation region\, they also pose new questions that seem to transcend t
 he role of the anisotropy. On the other hand\, two problems slow down furt
 her research in this area. One is the SNR reached with current telescopes\
 , which is insufficient to compare observations with time-resolved simulat
 ions of scattering polarization. And the other is the extension and comple
 xity of the formation region of the polarization signals\, which often dem
 ands analysis of multidimensional simulations to extract conclusions. In t
 his regard\, I seek to develop a standard model for polarization that is p
 recise enough to explain the signals but simple enough to provide analyses
  without relying in MHD models. We will start this seminar by summarizing 
 the physical situation concerning the formation of dynamical LP in the ext
 ernal solar layers and by supporting the need of investigating the circula
 r polarization. We will then focus on the novel exploration of NLTE circul
 ar polarization considering atomic orientation and velocity gradients. Thi
 s approach leads to a better understanding of the formation of polarizatio
 n by avoiding the limb-darkening modulation (introduced by the anisotropy 
 in LP) and by allowing effective comparisons with observations. To explain
  this I will advance some observational results and I will present the fir
 st version of a simple and insightful model for explaining NLTE polarizati
 on signals. A particularity of the approach here proposed is the associati
 on of the zeroes of the emergent polarization spectrum with its morphology
  and with the properties of the scattering medium.\nSpeaker: Edgar S. Carl
 in 
LAST-MODIFIED:20260220T073313Z
LOCATION:Instituto de Astrofísica de Canarias (broadcasted at MPS)\, Room:
  Auditorium
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Formation and morphology of solar circul
 ar polarization with dichroism\, atomic polarization and velocity gradient
 s (Edgar S. Carlin)
URL;VALUE=URI:https://www.mps.mpg.de/events/18582/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/19000/7840847
DTSTART:20190620T090000Z
DTEND:20190620T100000Z
CLASS:PUBLIC
CREATED:20190613T122005Z
DESCRIPTION:Speaker: Ioannis Kontogiannis 
LAST-MODIFIED:20260220T073301Z
LOCATION:Instituto de Astrofísica de Canarias (broadcasted at MPS)\, Room:
  Online only
ORGANIZER;CN=AIP:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Emergence of small-scale magnetic flux i
 n the quiet Sun\, observed from the photosphere to the corona (Ioannis Kon
 togiannis)
URL;VALUE=URI:https://www.mps.mpg.de/events/19000/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/20192/7840847
DTSTART:20190912T090000Z
DTEND:20190912T100000Z
CLASS:PUBLIC
CREATED:20190905T085552Z
DESCRIPTION:Speaker: JiaJia Liu 
LAST-MODIFIED:20260220T073247Z
LOCATION:Plasma Dynamics Group\, University of Sheffield (broadcasted at MP
 S)\, Room: Seminar rooms Aquila + Bootes
ORGANIZER;CN=Andreas Lagg:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Swirls and Alfvén pulses in the Solar A
 tmosphere (JiaJia Liu)
URL;VALUE=URI:https://www.mps.mpg.de/events/20192/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/20638/7840847
DTSTART:20190926T090000Z
DTEND:20190926T100000Z
CLASS:PUBLIC
CREATED:20190919T130725Z
DESCRIPTION:Speaker: Paolo Romano 
LAST-MODIFIED:20260220T073234Z
LOCATION:University of Catania / INAF - Catania Astrophysical Observatory (
 broadcasted at MPS)\, Room: Seminar rooms Cygnus + Draco
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: The largest flares of solar cycle 24 as 
 potential clues for stellar superflares (Paolo Romano)
URL;VALUE=URI:https://www.mps.mpg.de/events/20638/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/21746/7840847
DTSTART:20191010T090000Z
DTEND:20191010T100000Z
CLASS:PUBLIC
CREATED:20191004T091326Z
DESCRIPTION:Speaker: Daniel Nóbrega-Siverio
LAST-MODIFIED:20260220T073221Z
LOCATION:Rosseland Centre for Solar Physics\, University of Oslo (broadcast
 ed at MPS)\, Room: Seminar rooms Aquila + Bootes
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Nonequilibrium ionization and ambipolar 
 diffusion in magnetic flux emergence processes (Daniel Nóbrega-Siverio)
URL;VALUE=URI:https://www.mps.mpg.de/events/21746/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/22055/7840847
DTSTART:20191024T090000Z
DTEND:20191024T100000Z
CLASS:PUBLIC
CREATED:20191022T151307Z
DESCRIPTION:Speaker: Petros Syntelis
LAST-MODIFIED:20260220T073206Z
LOCATION:University of St Andrews broadcasted at MPS\, Room: Seminar room G
 emini
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Eruptions and flaring activity in emergi
 ng quadrupolar regions (Petros Syntelis) 
URL;VALUE=URI:https://www.mps.mpg.de/events/22055/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/22420/7840847
DTSTART:20191107T100000Z
DTEND:20191107T110000Z
CLASS:PUBLIC
CREATED:20191104T153230Z
DESCRIPTION:Speaker: Anwar Ali Aldhafeeri 
LAST-MODIFIED:20260220T073142Z
LOCATION:The University of Sheffield (broadcasted at MPS)\, Room: Seminar r
 oom Gemini
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: MHD wave modes in the solar magnetic flu
 x tubes with elliptical cross-section (Anwar Ali Aldhafeeri) 
URL;VALUE=URI:https://www.mps.mpg.de/events/22420/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/22667/7840847
DTSTART:20191107T100000Z
DTEND:20191107T110000Z
CLASS:PUBLIC
CREATED:20191114T132702Z
DESCRIPTION:Speaker: Julius Koza
LAST-MODIFIED:20260220T073154Z
LOCATION:Astronomical Institute\, Slovak Academy of Sciences (broadcasted a
 t MPS)\, Room: Seminar room Gemini
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Spectral diagnostics of cool flare loops
  observed by SST (Julius Koza)
URL;VALUE=URI:https://www.mps.mpg.de/events/22667/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/23063/7840847
DTSTART:20191205T100000Z
DTEND:20191205T110000Z
CLASS:PUBLIC
CREATED:20191128T173402Z
DESCRIPTION:Speaker: Mariarita Murabito 
LAST-MODIFIED:20260220T073127Z
LOCATION:INAF-OAR National Institute for Astrophysics\, Italy (broadcasted 
 at MPS)\, Room: Seminar rooms Aquila + Bootes
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Penumbral brightening events (Mariarita 
 Murabito)
URL;VALUE=URI:https://www.mps.mpg.de/events/23063/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/23203/7840847
DTSTART:20191219T100000Z
DTEND:20191219T110000Z
CLASS:PUBLIC
CREATED:20191212T160942Z
DESCRIPTION: The variation in solar irradiance is commonly assumed to be dr
 iven by its surface magnetism. Until recently\, this assumption could not 
 be verified conclusively as models of solar irradiance variability based o
 n solar surface magnetism have to be calibrated to solar irradiance measur
 ements. Making use of realistic three-dimensional magnetohydrodynamic simu
 lations of the solar atmosphere and state-of-the-art full-disk magnetogram
 s from SDO\, we developed a model of total solar irradiance (TSI) that doe
 s not require any such calibration. The modelled TSI variability is theref
 ore\, unlike preceding models\, independent of TSI measurements. The model
  replicates over 95% of the observed variability over the lifetime of SDO\
 , confirming the relationship to solar surface magnetism and leaving limit
 ed scope for alternative drivers of solar irradiance variability (at least
  over the time scales examined\, that is\, days to years).\nSpeaker: Kok L
 eng Yeo
LAST-MODIFIED:20260220T073112Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Auditorium
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Solar irradiance variability and surface
  magnetism (Kok Leng Yeo)
URL;VALUE=URI:https://www.mps.mpg.de/events/23203/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/23576/7840847
DTSTART:20200123T100000Z
DTEND:20200123T110000Z
CLASS:PUBLIC
CREATED:20200117T151909Z
DESCRIPTION: The magnetic Rayleigh–Taylor instability is a fundamental MH
 D instability and recent observations show that this instability develops 
 in the solar prominences. We analyze the observations from Solar Dynamic O
 bservatory/Atmospheric Imaging Assembly of a MRT unstable loop-like promin
 ence. Initially\, some small-scale perturbations are developed horizontall
 y and vertically at the prominence-cavity interface. These perturbations a
 re associated with the hot and low dense coronal plasma as compared to the
  surrounding prominence. The interface supports magneto-thermal convection
  process\, which acts as a buoyancy to launch the hot and low denser plume
 s (P1 and P2) propagating with the speed of 35–46 km s-1 in the overlyin
 g prominence. The self-similar plume formation initially shows the growth 
 of a linear MRT-unstable plume (P1)\, and thereafter the evolution of a no
 nlinear single-mode MRT-unstable second plume (P2). A differential emissio
 n measure analysis shows that plumes are less denser and hotter than the p
 rominence. We have estimated the observational growth rate for both the pl
 umes as 1.32±0.29×10−3 s−1 and 1.48±0.29×10^−3 s^−1\, respecti
 vely\, which are comparable to the estimated theoretical growth rate (1.95
 ×10^−3 s^−1). Later\, these MRT unstable plumes get stabilize via for
 mation of rolled (vortex-like) plasma structures at the prominence-cavity 
 interface in the downfalling plasma. These rolled-plasma structures depict
  Kelvin-Helmholtz instability\, which corresponds to the nonlinear phase o
 f MRT instability. However\, even after the full development of MRT instab
 ility\, the overlying prominence is not erupted. Later\, a Rayleigh-Taylor
  unstable tangled plasma thread is evident in the rising segment of this p
 rominence. This tangled thread is subjected to the compression between eru
 ption site and overlying dense prominence at the interface. This compressi
 on initiates strong shear at the prominence-cavity interface and causes Ke
 lvin-Helmholtz vortex-like structures. Due to this shear motion\, the plas
 ma downfall is occurred at the right part of the prominence–cavity bound
 ary. It triggers the characteristic KH unstable vortices and MRT-unstable 
 plasma bubbles propagating at different speeds and merging with each other
 . The shear motion and lateral plasma downfall may initiate hybrid KH-RT i
 nstability there.\nSpeaker: Sudheer K. Mishra
LAST-MODIFIED:20260220T073050Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Aquila + Bo
 otes
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Magnetic Rayleigh–Taylor Unstable Plum
 es and Hybrid KH-RT Instability into a Loop-like Eruptive Prominence (Sudh
 eer K. Mishra)
URL;VALUE=URI:https://www.mps.mpg.de/events/23576/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/24196/7840847
DTSTART:20200220T100000Z
DTEND:20200220T110000Z
CLASS:PUBLIC
CREATED:20200217T123758Z
DESCRIPTION: During a solar flare\, it is believed that reconnection takes 
 place in the corona followed by fast energy transport to the chromosphere.
  The resulting intense heating strongly disturbs the chromospheric structu
 re and induces complex radiation hydrodynamic effects. Interpreting the ph
 ysics of the flaring solar atmosphere is one of the most challenging tasks
  in solar physics. We present a novel deep learning approach\, an invertib
 le neural network\, to understanding the chromospheric physics of a flarin
 g solar atmosphere via the inversion of observed solar line profiles in H&
 amp\;alpha\; and Ca II &amp\;lambda\;8542. The network is trained using fl
 are simulations from the 1D radiation hydrodynamic code RADYN as the expec
 ted atmosphere and line profile. This model is then applied to whole image
 s from an observation of an M1.1 solar flare taken with the Swedish 1 m So
 lar Telescope/CRisp Imaging SpectroPolarimeter instrument. The inverted at
 mospheres obtained from observations provide physical information on the e
 lectron number density\, temperature and bulk velocity flow of the plasma 
 throughout the solar atmosphere ranging in height from 0 to 10 Mm. Our met
 hod can invert a 1k x 1k field-of-view in approximately 30 minutes and we 
 show results from the whole image inversions and error calculations on the
  inversions. Furthermore\, we delve into the mammoth task of analysing the
  wealth of data we have accumulated through these inversions. The magnetic
  Rayleigh–Taylor instability is a fundamental MHD instability and recent
  observations show that this instability develops in the solar prominences
 . We analyze the observations from Solar Dynamic Observatory/Atmospheric I
 maging Assembly of a MRT unstable loop-like prominence. Initially\, some s
 mall-scale perturbations are developed horizontally and vertically at the 
 prominence-cavity interface. These perturbations are associated with the h
 ot and low dense coronal plasma as compared to the surrounding prominence.
  The interface supports magneto-thermal convection process\, which acts as
  a buoyancy to launch the hot and low denser plumes (P1 and P2) propagatin
 g with the speed of 35–46 km s-1 in the overlying prominence. The self-s
 imilar plume formation initially shows the growth of a linear MRT-unstable
  plume (P1)\, and thereafter the evolution of a nonlinear single-mode MRT-
 unstable second plume (P2). A differential emission measure analysis shows
  that plumes are less denser and hotter than the prominence. We have estim
 ated the observational growth rate for both the plumes as 1.32±0.29×10
 −3 s−1 and 1.48±0.29×10^−3 s^−1\, respectively\, which are compa
 rable to the estimated theoretical growth rate (1.95×10^−3 s^−1). Lat
 er\, these MRT unstable plumes get stabilize via formation of rolled (vort
 ex-like) plasma structures at the prominence-cavity interface in the downf
 alling plasma. These rolled-plasma structures depict Kelvin-Helmholtz inst
 ability\, which corresponds to the nonlinear phase of MRT instability. How
 ever\, even after the full development of MRT instability\, the overlying 
 prominence is not erupted. Later\, a Rayleigh-Taylor unstable tangled plas
 ma thread is evident in the rising segment of this prominence. This tangle
 d thread is subjected to the compression between eruption site and overlyi
 ng dense prominence at the interface. This compression initiates strong sh
 ear at the prominence-cavity interface and causes Kelvin-Helmholtz vortex-
 like structures. Due to this shear motion\, the plasma downfall is occurre
 d at the right part of the prominence–cavity boundary. It triggers the c
 haracteristic KH unstable vortices and MRT-unstable plasma bubbles propaga
 ting at different speeds and merging with each other. The shear motion and
  lateral plasma downfall may initiate hybrid KH-RT instability there.\nSpe
 aker: John Armstrong
LAST-MODIFIED:20260220T073022Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Aquila + Bo
 otes
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Learning to Invert Solar Flares with RAD
 YN Physics
URL;VALUE=URI:https://www.mps.mpg.de/events/24196/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/25158/7840847
DTSTART:20200220T100000Z
DTEND:20200220T110000Z
CLASS:PUBLIC
CREATED:20200619T123806Z
DESCRIPTION: During a solar flare\, it is believed that reconnection takes 
 place in the corona followed by fast energy transport to the chromosphere.
  The resulting intense heating strongly disturbs the chromospheric structu
 re and induces complex radiation hydrodynamic effects. Interpreting the ph
 ysics of the flaring solar atmosphere is one of the most challenging tasks
  in solar physics. We present a novel deep learning approach\, an invertib
 le neural network\, to understanding the chromospheric physics of a flarin
 g solar atmosphere via the inversion of observed solar line profiles in H&
 amp\;alpha\; and Ca II &amp\;lambda\;8542. The network is trained using fl
 are simulations from the 1D radiation hydrodynamic code RADYN as the expec
 ted atmosphere and line profile. This model is then applied to whole image
 s from an observation of an M1.1 solar flare taken with the Swedish 1 m So
 lar Telescope/CRisp Imaging SpectroPolarimeter instrument. The inverted at
 mospheres obtained from observations provide physical information on the e
 lectron number density\, temperature and bulk velocity flow of the plasma 
 throughout the solar atmosphere ranging in height from 0 to 10 Mm. Our met
 hod can invert a 1k x 1k field-of-view in approximately 30 minutes and we 
 show results from the whole image inversions and error calculations on the
  inversions. Furthermore\, we delve into the mammoth task of analysing the
  wealth of data we have accumulated through these inversions. The magnetic
  Rayleigh–Taylor instability is a fundamental MHD instability and recent
  observations show that this instability develops in the solar prominences
 . We analyze the observations from Solar Dynamic Observatory/Atmospheric I
 maging Assembly of a MRT unstable loop-like prominence. Initially\, some s
 mall-scale perturbations are developed horizontally and vertically at the 
 prominence-cavity interface. These perturbations are associated with the h
 ot and low dense coronal plasma as compared to the surrounding prominence.
  The interface supports magneto-thermal convection process\, which acts as
  a buoyancy to launch the hot and low denser plumes (P1 and P2) propagatin
 g with the speed of 35–46 km s-1 in the overlying prominence. The self-s
 imilar plume formation initially shows the growth of a linear MRT-unstable
  plume (P1)\, and thereafter the evolution of a nonlinear single-mode MRT-
 unstable second plume (P2). A differential emission measure analysis shows
  that plumes are less denser and hotter than the prominence. We have estim
 ated the observational growth rate for both the plumes as 1.32±0.29×10
 −3 s−1 and 1.48±0.29×10^−3 s^−1\, respectively\, which are compa
 rable to the estimated theoretical growth rate (1.95×10^−3 s^−1). Lat
 er\, these MRT unstable plumes get stabilize via formation of rolled (vort
 ex-like) plasma structures at the prominence-cavity interface in the downf
 alling plasma. These rolled-plasma structures depict Kelvin-Helmholtz inst
 ability\, which corresponds to the nonlinear phase of MRT instability. How
 ever\, even after the full development of MRT instability\, the overlying 
 prominence is not erupted. Later\, a Rayleigh-Taylor unstable tangled plas
 ma thread is evident in the rising segment of this prominence. This tangle
 d thread is subjected to the compression between eruption site and overlyi
 ng dense prominence at the interface. This compression initiates strong sh
 ear at the prominence-cavity interface and causes Kelvin-Helmholtz vortex-
 like structures. Due to this shear motion\, the plasma downfall is occurre
 d at the right part of the prominence–cavity boundary. It triggers the c
 haracteristic KH unstable vortices and MRT-unstable plasma bubbles propaga
 ting at different speeds and merging with each other. The shear motion and
  lateral plasma downfall may initiate hybrid KH-RT instability there.\nSpe
 aker: John Armstrong
LAST-MODIFIED:20260220T073033Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Aquila + Bo
 otes
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Learning to Invert Solar Flares with RAD
 YN Physics
URL;VALUE=URI:https://www.mps.mpg.de/events/25158/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/24396/7840847
DTSTART:20200305T100000Z
DTEND:20200305T110000Z
CLASS:PUBLIC
CREATED:20200227T154844Z
DESCRIPTION: Studying the polarization properties of penumbral microjets th
 at have the shortest durations requires spectropolarimetric observations w
 ith the fastest temporal cadence possible and is currently a challenging t
 ask. Here\, we approach this task using fast-cadence spectropolarimetric m
 easurements of the Ca II 8542 A line made with the CRISP instrument at the
  Swedish 1 m Solar Telescope. We exploited the diagnosis capabilities of t
 his line to retrieve the magnetic field configuration and its evolution in
  the upper photosphere and low chromosphere by applying the weak field app
 roximation to its wings and line core wavelengths respectively. We found t
 hat the short-lived microjets are associated with a transient perturbation
  in the photospheric magnetic field and sometimes they show clear but weak
 er changes in the chromospheric field as well. We will describe the differ
 ent types of evolution that were identified.\nSpeaker: Azaymi Litzi Siu Ta
 pia 
LAST-MODIFIED:20260220T073009Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Aquila + Bo
 otes
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESPOS Online Seminar: Magnetic properties of short-lived pen
 umbral microjets (Azaymi Litzi Siu Tapi) 
URL;VALUE=URI:https://www.mps.mpg.de/events/24396/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/24779/7840847
DTSTART:20200514T090000Z
DTEND:20200514T100000Z
CLASS:PUBLIC
CREATED:20200507T110928Z
DESCRIPTION:We present the application of the weighted horizontal gradient 
 of magnetic field (WGM) flare prediction method to 3D extrapolated magneti
 c configurations of flaring solar ARs. The main aim is to identify an opti
 mal height range\, if any\, in the interface region between the photospher
 e and lower corona\, where the flare onset time prediction capability of W
 GM is best exploited. The optimal height is where flare prediction\, by me
 ans of the WGM method\, is achieved earlier than at the photospheric level
 . 3D magnetic structures\, based on potential and non-linear force-free fi
 eld extrapolations\, are constructed to study a vertical range from the ph
 otosphere up to the low corona with a 45 km step size. We found that apply
 ing the WGM method between 1000 and 1800 km above the solar surface would 
 improve the prediction of the flare onset time by around 2-8 hrs. Certain 
 caveats and an outlook for future work along these lines are also discusse
 d.\nSpeaker: Marianna Korsos 
LAST-MODIFIED:20260220T072954Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Solar Flare Prediction Using Magnetic Fi
 eld Diagnostics Above the Photosphere (Marianna Korsos) 
URL;VALUE=URI:https://www.mps.mpg.de/events/24779/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/24842/7840847
DTSTART:20200528T090000Z
DTEND:20200528T100000Z
CLASS:PUBLIC
CREATED:20200525T093140Z
DESCRIPTION:Solar flares and eruptions are one of the most energetic phenom
 ena occuring in the solar system. They are typically described by the cart
 oon-like 2D Standard model of solar flares. This model is however not capa
 ble of describing J-shaped (hooked) solar flare ribbons\, bright elongated
  structures typically observed in the UV part of the spectrum. Their descr
 iption requires 3D MHD modelling of magnetic flux ropes\, bundles of twist
 ed field lines rooted in the hooked endings of flare ribbons. The standard
  flare model in three dimensions\, developed in the Observatory of Paris\,
  was recently used to find predictions on how do the field lines reconnect
  during solar eruptions with respect to the positions of flare ribbons (Au
 lanier &amp\; Dudík 2019\, A&amp\;A\, 621\, 72). Authors of this study id
 entified three geometries involving field lines composing and/or surroundi
 ng the erupting flux rope. With a help of high-resolution EUV data\, these
  were identified in a series of publications focused on eruptive events. U
 sing data from the Atmospheric Imaging Assembly (AIA) onboard the Solar Dy
 namics Observatory\, we will present the manifestations of the different 3
 D reconnection scenarios and discuss under what conditions can their const
 ituents be observed. We present the application of the weighted horizontal
  gradient of magnetic field (WGM) flare prediction method to 3D extrapolat
 ed magnetic configurations of flaring solar ARs. The main aim is to identi
 fy an optimal height range\, if any\, in the interface region between the 
 photosphere and lower corona\, where the flare onset time prediction capab
 ility of WGM is best exploited. The optimal height is where flare predicti
 on\, by means of the WGM method\, is achieved earlier than at the photosph
 eric level. 3D magnetic structures\, based on potential and non-linear for
 ce-free field extrapolations\, are constructed to study a vertical range f
 rom the photosphere up to the low corona with a 45 km step size. We found 
 that applying the WGM method between 1000 and 1800 km above the solar surf
 ace would improve the prediction of the flare onset time by around 2-8 hrs
 . Certain caveats and an outlook for future work along these lines are als
 o discussed.\nSpeaker: Juraj Lorinčík 
LAST-MODIFIED:20260220T072940Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Understanding hooks of solar flare ribbo
 ns and the evolution of coronal mass ejections (Juraj Lorinčík)
URL;VALUE=URI:https://www.mps.mpg.de/events/24842/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/24885/7840847
DTSTART:20200611T090000Z
DTEND:20200611T100000Z
CLASS:PUBLIC
CREATED:20200528T152424Z
DESCRIPTION:Propagating kink waves have been reported recently and have bee
 n found to be ubiquitous in the solar corona including in the quiet Sun. I
 t is imperative to understand the mechanisms that enable their energy to b
 e transferred to the plasma. Carrying on the legacy of the standing kink w
 aves\, mode conversion via resonant absorption is thought to be one of the
  main mechanisms for damping of these propagating kink waves\, and is cons
 idered to play a key role in the process of energy transfer. We use the Do
 ppler velocity images of the Coronal Multi-channel Polarimeter (CoMP) for 
 the study of propagating kink waves in quiescent coronal loops. A coherenc
 e-based method is used to track the Doppler velocity signal of the waves\,
  enabling an investigation into the spatial evolution of velocity perturba
 tions. To enable accurate estimates of these quantities\, the first deriva
 tion is provided of a likelihood function suitable for fitting models to t
 he ratio of two power spectra obtained from discrete Fourier transforms. M
 aximum likelihood estimation is used to fit an exponential damping model t
 o the observed variation in power ratio as a function of frequency. This a
 lso confirms earlier indications that propagating kink waves are undergoin
 g frequency-dependent damping. Additionally\, it is found that the rate of
  damping decreases for longer coronal loops that reach higher in the coron
 a. The analysis techniques are used to create a statistical sample of quie
 scent loops to study the statistical properties of propagating kink waves 
 and compare it to the studies of standing kink waves. It is noted that the
  damping for the propagating waves appears to be significantly weaker than
  that found from measurements of standing kink modes. The propagating kink
  waves also exhibit signatures of power amplification of waves. These prop
 agating kink waves provide a new avenue to perform coronal magneto-seismol
 ogy even during the quiet Sun period and this reliable method is not limit
 ed by requiring the eruptive activity of the Sun.\nSpeaker: Ajay Tiwari
LAST-MODIFIED:20260220T072926Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESP Online Seminar: Study of damping of propagating kink wav
 es in the solar corona (Ajay Tiwari)
URL;VALUE=URI:https://www.mps.mpg.de/events/24885/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/28447/7840847
DTSTART:20210603T090000Z
DTEND:20210603T100000Z
CLASS:PUBLIC
CREATED:20210602T133815Z
DESCRIPTION:The Mg I b2 line at 5173 Å forms over a large range of heights
  but itscore\, which forms under conditions of non-local thermodynamicequi
 librium\, is most sensitive to heights near the temperature minimum\,a reg
 ion of the solar atmosphere that has not been sufficientlyexplored. The ne
 xt-generation solar observatories will have access tothis spectral line an
 d will allow for multi-line observations to studythe different layers of t
 he solar atmosphere simultaneously and withunprecedented polarimetric sens
 itivity. We will present a morphologicalclassification of the intensity an
 d circular polarization profiles ofthis spectral line at high-spatial-reso
 lution\, using observations fromthe Swedish 1-m Solar Telescope. We will a
 lso discuss the results of theweak field approximation applied to the Mg I
  b2 line\, and theircomparison with inversion results of the Fe I 6173 Å 
 line to understandhow the magnetic field changes with height in the solar 
 atmosphere.\nSpeaker: Azaymi Litzi Siu Tapia 
LAST-MODIFIED:20260219T095205Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESPOS Online Seminar: The solar atmosphere as observed throu
 gh the Mg I b2 line at highspatial resolution (Azaymi Litzi Siu Tapia)
URL;VALUE=URI:https://www.mps.mpg.de/events/28447/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/28520/7840847
DTSTART:20210603T090000Z
DTEND:20210603T100000Z
CLASS:PUBLIC
CREATED:20210610T111034Z
DESCRIPTION:The Mg I b2 line at 5173 Å forms over a large range of heights
  but itscore\, which forms under conditions of non-local thermodynamicequi
 librium\, is most sensitive to heights near the temperature minimum\,a reg
 ion of the solar atmosphere that has not been sufficientlyexplored. The ne
 xt-generation solar observatories will have access tothis spectral line an
 d will allow for multi-line observations to studythe different layers of t
 he solar atmosphere simultaneously and withunprecedented polarimetric sens
 itivity. We will present a morphologicalclassification of the intensity an
 d circular polarization profiles ofthis spectral line at high-spatial-reso
 lution\, using observations fromthe Swedish 1-m Solar Telescope. We will a
 lso discuss the results of theweak field approximation applied to the Mg I
  b2 line\, and theircomparison with inversion results of the Fe I 6173 Å 
 line to understandhow the magnetic field changes with height in the solar 
 atmosphere.\nSpeaker: Azaymi Litzi Siu Tapia 
LAST-MODIFIED:20260219T095214Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESPOS Online Seminar: The solar atmosphere as observed throu
 gh the Mg I b2 line at highspatial resolution (Azaymi Litzi Siu Tapia)
URL;VALUE=URI:https://www.mps.mpg.de/events/28520/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/28630/7840847
DTSTART:20210701T090000Z
DTEND:20210701T100000Z
CLASS:PUBLIC
CREATED:20210625T115156Z
DESCRIPTION:The X1.6 flare observed on 22 October 2014 (SOL2014-10-22T14:28
 ) was among the strongest flares that occurred in the magnetically complex
 \, great active region NOAA 12192. Despite the large amount of released en
 ergy\, it was a confined flare\, without an accompanying CME. In our work 
 we attempt to deepen our understanding of the magnetic field configuration
  of the active region NOAA 12192. We analyzed the polarization signatures 
 during the flare using full spectro-polarimetric data acquired by the IBIS
 /DST instrument along the photospheric Fe I 617.3 nm and the chromospheric
  Ca II 854.2 nm lines in a one-hour time interval immediately following th
 e peak of the X1.6 flare. The results obtained provide evidence of signifi
 cant changes in the magnetic field configuration of the chromosphere durin
 g the analyzed time interval.\nSpeaker: Fabiana Ferrente
LAST-MODIFIED:20260219T095155Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Pradeep Chitta:mailto:
SUMMARY:ESPOS: ESPOS Online Seminar: Polarization signatures during the X1.
 6 flare observed in active region NOAA 12192 (Fabiana Ferrente)
URL;VALUE=URI:https://www.mps.mpg.de/events/28630/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/29284/7840847
DTSTART:20210707T090000Z
DTEND:20210707T100000Z
CLASS:PUBLIC
CREATED:20211004T100118Z
DESCRIPTION:The Space Weather effects in the near-Earth environment as well
  as in atmospheres of other terrestrial planets arise by corpuscular radia
 tion from the Sun\, known as the solar wind. The solar magnetic fields gov
 ern the solar corona structure. Magnetic-field strength values in the sola
 r wind sources - key information for modeling and forecasting the Space We
 ather climate - are derived from various solar space- and ground-based obs
 ervations\, but\, so far not accounting for specific types of radio bursts
 . These are “fractured” type II radio bursts attributed to collisions 
 of shock waves with coronal structures emitting the solar wind. Here\, we 
 report about radio observations of two “fractured” type II bursts to d
 emonstrate a novel tool for probing of magnetic field variations in the so
 lar wind sources. These results have direct impact on interpretations of t
 his class of bursts and contribute to the current studies of the solar win
 d emitters.\nSpeaker: Artem Koval 
LAST-MODIFIED:20211004T100806Z
LOCATION:Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Online Seminar: Shock-wave radio probing of solar wind
  sources in coronal magnetic fields (Artem Koval 
URL;VALUE=URI:https://www.mps.mpg.de/events/29284/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/29444/7840847
DTSTART:20211021T090000Z
DTEND:20211021T100000Z
CLASS:PUBLIC
CREATED:20211015T094938Z
DESCRIPTION:Minifilaments are miniature versions of filaments\, first obser
 ved in H-alpha filtergrams of quiet Sun. Recent studies have showcased the
 ir association with small-scale eruptive events\, highlighting their impor
 tance in energetic processes of the quiet Sun. We present the first detail
 ed study of such an event\, using high-cadence\, high-spectral resolution 
 imaging observations. The minifilament formed between small-scale\, opposi
 te-polarity magnetic concentrations and erupted within an hour after its a
 ppearance in H-alpha\, exhibiting a twisted\, thread-like structure. Its e
 ruption took place in two phases (slow and fast)\, producing a coronal dim
 ming\, while part of the erupting material returned to the chromosphere. T
 he observed similarities to large-scale filament eruptions indicate the ac
 tion of common mechanisms. Their properties\, combined with their abundanc
 e in quiet Sun\, constitute minifilaments ideal targets for the new ground
 -based solar telescopes.\nSpeaker: Ioannis Kontogiannis 
LAST-MODIFIED:20211015T095719Z
LOCATION:Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Online Seminar: High-resolution spectroscopy of a mini
 filament eruption (Ioannis Kontogiannis)
URL;VALUE=URI:https://www.mps.mpg.de/events/29444/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/29582/7840847
DTSTART:20211104T100000Z
DTEND:20211104T110000Z
CLASS:PUBLIC
CREATED:20211029T112053Z
DESCRIPTION:Solar flares originate from active regions (ARs) hosting comple
 x and strong bipolar magnetic fluxes. Forecasting the probability of an AR
  to flare and defining reliable precursors of intense flares\, i.e.\, X- o
 r M-class flares\, are extremely challenging tasks in the space weather fi
 eld. In this talk\, we focus on two metrics as flare precursors\, the unsi
 gned flux R*\, tested on MDI/SOHO data and calibrated for higher spatial r
 esolution SDO/HMI maps\, and a novel topological parameter D representing 
 the complexity of a solar active region. The parameter D is based on the a
 utomatic recognition of magnetic polarity inversion lines (PILs) in identi
 fied SDO/HMI ARs and is able to evaluate their magnetic topological comple
 xity. We use both a heuristic approach and a supervised machine-learning m
 ethod to validate the effectiveness of these metrics to predict the occurr
 ence of X- or M-class flares in a given solar AR during the following 24 h
 r period. Our feature ranking analysis shows that both parameters play a s
 ignificant role in prediction performances. Moreover\, the analysis demons
 trates that the new topological parameter D is the only one\, among 173 ov
 erall predictors\, that is systematically ranked within the top 10 positio
 ns.\nSpeaker: Luca Giovannelli 
LAST-MODIFIED:20260219T095145Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Online Seminar: Forecasting solar flares with a new to
 pological parameter and a supervised machine-learning method (Luca Giovann
 elli)
URL;VALUE=URI:https://www.mps.mpg.de/events/29582/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/29663/7840847
DTSTART:20211118T100000Z
DTEND:20211118T110000Z
CLASS:PUBLIC
CREATED:20211112T102414Z
DESCRIPTION:Magnetic reconnection is widely accepted to be a major contribu
 tor to nonthermal particle acceleration in the solar atmosphere. We invest
 igate particle acceleration in two evolving field geometries: first in an 
 isolated tearing current sheet\, then in a full-scale coronal jet. Both ge
 ometries involve 3D reconnection with at least one magnetic null point. A 
 test-particle approach is employed\, using electromagnetic fields from mag
 netohydrodynamic (MHD) simulations of these geometries. Using this method\
 , we examine the trajectories of high-energy protons and electrons injecte
 d near reconnecting null points and how the directionality of their accele
 ration differs. We will discuss what the ejection and impact patterns of h
 eliosphere and photosphere-incident particles respectively can tell us abo
 ut the location\, size and shape of field structures that are formed in te
 aring current sheets during null-point reconnection in the solar corona. W
 e will also consider how we may observe the simulated differences between 
 proton and electron impact patterns.\nSpeaker: Ross Pallister 
LAST-MODIFIED:20260219T095116Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Seminar: Test-particle simulations at tearing coronal 
 null-point current sheets (Ross Pallister)
URL;VALUE=URI:https://www.mps.mpg.de/events/29663/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/29741/7840847
DTSTART:20211202T100000Z
DTEND:20211202T110000Z
CLASS:PUBLIC
CREATED:20211126T120851Z
DESCRIPTION:Invoking the effects of thermal conductivity\, compressive\, vi
 scosity\, radiative losses\, and heating-cooling misbalance\, we derive th
 e new general dispersion relation for the propagating slow MHD waves in th
 e solar corona and solve it to determine the phase shifts of density and t
 emperature perturbations along with their dependence on the equilibrium pa
 rameters of the plasma such as the background density and temperature. We 
 also derive a new generalised mathematical expression for the polytropic i
 ndex using the linear MHD model and find that in the presence of thermal c
 onduction alone it remains close to its classical value for all the consid
 ered equilibrium density and temperature observed in typical coronal loops
 . Under the considered heating and cooling models\, we find that the expec
 ted polytropic index can be matched with the observed value of 1.1 ± 0.02
  in typical coronal loops if the thermal conductivity is enhanced by an or
 der of magnitude compared to its classical value. We also explore the role
  of different heating functions for typical coronal parameters and find th
 at although the polytropic indices remain close to 5/3\, the phase differe
 nce between density and temperature perturbations is highly dependent on t
 he form of heating function.\nSpeaker: Abhinav Prasad 
LAST-MODIFIED:20260219T095058Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Seminar: Role of Heating-Cooling Misbalance on the Pha
 se Shift of Propagating Slow Waves in Non-adiabatic Solar Coronal Loops (A
 bhinav Prasad)
URL;VALUE=URI:https://www.mps.mpg.de/events/29741/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/30107/7840847
DTSTART:20220203T100000Z
DTEND:20220203T110000Z
CLASS:PUBLIC
CREATED:20220128T073307Z
DESCRIPTION:The physical conditions resulting in the formation and disappea
 rance of penumbral regions are poorly understood. We investigated these co
 nditions by using high-resolution spectropolarimetric observations of a su
 nspot penumbra from different instruments at ground- and space-based teles
 copes\, namely the SST/CRISP\, SDO/HMI\, and Hinode/SP. The studied data a
 llowed us to assess the evolution of the magnetic and velocity properties 
 of plasma in the observed region and to analyze the role of several proces
 ses found therein. The penumbra forms only on one side of the observed reg
 ion\, characterized by the absence of an overlying magnetic canopy. The pe
 numbra later disappears progressively in time and space. This final evolut
 ion of the studied region seems to be governed by the presence of moving m
 agnetic features (MMFs) and of overlying canopies.\nSpeaker: Mariarita Mur
 abito 
LAST-MODIFIED:20260219T095037Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Seminar: Formation and disappearance of a penumbra: Re
 cent results (Mariarita Murabito)
URL;VALUE=URI:https://www.mps.mpg.de/events/30107/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/30399/7840847
DTSTART:20220303T100000Z
DTEND:20220303T110000Z
CLASS:PUBLIC
CREATED:20220302T175459Z
DESCRIPTION:Observational precursors of large solar flares provide a basis 
 for future operational systems for forecasting. We studied the evolution o
 f the normalized emergence (EM)\, shearing (SH)\, and total (T) magnetic h
 elicity flux components for 14 flaring (with at least one X-class flare) a
 nd 14 nonflaring (&lt\;M5-class flares) active regions (ARs) using the Spa
 ce-weather Helioseismic Magnetic Imager Active Region Patches vector magne
 tic field data. Each of the selected ARs contain a δ-type spot. The three
  helicity components of these ARs were analyzed using wavelet analysis. Lo
 calized peaks of the wavelet power spectrum (WPS) were identified and stat
 istically investigated. We find that (i) the probability density function 
 of the identified WPS peaks for all the EM/SH/T profiles can be fitted wit
 h a set of Gaussian functions centered at distinct periods between ∼3 an
 d 20 hr. (ii) There is a noticeable difference in the distribution of peri
 ods found in the EM profiles between the flaring and nonflaring ARs\, whil
 e no significant difference is found in the SH and T profiles. (iii) In fl
 aring ARs\, the distributions of the shorter EM/SH/T periods (&lt\;10 hr) 
 split up into two groups after flares\, while the longer periods (&gt\;10 
 hr) do not change. (iv) When the EM periodicity does not contain harmonics
 \, the ARs do not host a large energetic flare. (v) Finally\, significant 
 power at long periods (∼20 hr) in the T and EM components may serve as a
  precursor for large energetic flares.\nSpeaker: Szabolcs Soós
LAST-MODIFIED:20220302T175924Z
LOCATION:Eötvös Loránd University (ELTE)\, Hungary  \, Room: Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Seminar: On the Differences in the Periodic Behavior o
 f Magnetic Helicity Flux in Flaring Active Regions (Szabolcs Soós)
URL;VALUE=URI:https://www.mps.mpg.de/events/30399/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/30400/7840847
DTSTART:20220317T100000Z
DTEND:20220317T110000Z
CLASS:PUBLIC
CREATED:20220302T180052Z
DESCRIPTION:Speaker: Juan Camilo Guevara Gómez
LAST-MODIFIED:20260219T154233Z
LOCATION:Max-Planck-Institut für Sonnensystemforschung\, Room: Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Seminar: Small-scale MHD waves in the solar chromosphe
 re with ALMA (Juan Camilo Guevara Gómez)
URL;VALUE=URI:https://www.mps.mpg.de/events/30400/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/30401/7840847
DTSTART:20220331T090000Z
DTEND:20220331T100000Z
CLASS:PUBLIC
CREATED:20220302T180152Z
DESCRIPTION:Speaker: Susanna Parenti
LAST-MODIFIED:20220324T115920Z
LOCATION:Zoom
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: Validation of a wave heated 3D MHD coronal-wind model using 
 Polarized Brightness and EUV observations
URL;VALUE=URI:https://www.mps.mpg.de/events/30401/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/30450/7840847
DTSTART:20220428T090000Z
DTEND:20220428T100000Z
CLASS:PUBLIC
CREATED:20220310T125942Z
DESCRIPTION:The analytical and numerical modelling of the behaviour of magn
 etohydrodynamic (MHD) waves in various magnetic geometries is a constantly
  evolving\, active area of research within the field of solar magneto-seis
 mology. Here\, we present our findings on MHD wave propagation and instabi
 lities in a family of asymmetric Cartesian waveguide models. Thanks to the
  introduction of various sources of asymmetry (background density\, magnet
 ic field or flow speed)\, this generalisation of classical (symmetric) sla
 b geometries allows us to refine our modelling of several important featur
 es in the richly structured solar atmosphere. Including background asymmet
 ry in these configurations influences the phase speeds and cut-off frequen
 cies of the eigenmodes\, and\, in the case of flow asymmetry\, it can also
  change the threshold for the onset of the Kelvin-Helmholtz instability. F
 urthermore\, the asymmetric nature of the models allows us to develop sola
 r magneto-seismologic tools and provide efficient methods for obtaining fu
 rther information about the solar plasma from current and future high-reso
 lution observations of multi-layered waveguides (such as e.g. magnetic bri
 ght points or light walls).
LAST-MODIFIED:20220426T195914Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Seminar: MHD wave propagation asymmetric solar wavegui
 des (Noémi Kinga Zsámberger) 
URL;VALUE=URI:https://www.mps.mpg.de/events/30450/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/31218/7840847
DTSTART:20220512T090000Z
DTEND:20220512T100000Z
CLASS:PUBLIC
CREATED:20220505T122028Z
DESCRIPTION:Plasmoid-mediated fast magnetic reconnection plays a fundamenta
 l role in driving explosive dynamics and heating in the solar atmosphere\,
  but relatively little is known about how it develops in partially ionised
  plasmas (PIP) of the chromosphere. Partial ionisation can largely alter t
 he dynamics of the coalescence instability\, which promotes fast reconnect
 ion and forms a turbulent reconnecting current sheet through plasmoid inte
 raction\, but it is still unclear to what extent PIP effects influence thi
 s process. In this talk\, I investigate the role of collisional ionisation
  and recombination in the development of plasmoid coalescence: I will pres
 ent 1D and 2.5D simulations of a two-fluid model of a partially ionised pl
 asma (PIP) and show how the dynamics change in the presence and absence of
  ionisation and recombination processes. The aim is to understand whether 
 these two-fluid coupling processes play a role in accelerating reconnectio
 n. In 1D calculations\, as the current sheet collapses it drives a burst o
 f ionisation. This results in the current of the current sheet growing at 
 a slower rate than calculations without ionisation and recombination\, and
  in a thicker current sheet. In 2.5D calculations\, it is found that\, in 
 general\, ionisation-recombination process slow down the coalescence. Unli
 ke our previous models that included thermal collisions only\, ionisation 
 and recombination stabilise current sheets and suppress non-linear dynamic
 s\, with turbulent reconnection occurring in limited cases: bursts of ioni
 sation lead to the formation of thicker current sheets\, even when radiati
 ve losses are included to cool the system. Therefore\, the coalescence tim
 e scale is very sensitive to ionisation-recombination processes.\nSpeaker:
  Giulia Murtas (University of Exeter\, United Kingdom)  
LAST-MODIFIED:20220505T122253Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Seminar: Collisional ionisation and recombination effe
 cts on coalescence instability in chromospheric partially ionised plasmas 
 (Giulia Murtas) 
URL;VALUE=URI:https://www.mps.mpg.de/events/31218/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/32565/7840847
DTSTART:20221020T090000Z
DTEND:20221020T100000Z
CLASS:PUBLIC
CREATED:20221017T151034Z
DESCRIPTION:Speaker: Michaela Brchnelova (KU Leuven\, Belgium)
LAST-MODIFIED:20221017T151659Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS Seminar: Coronal modelling: the good\, the bad and the
  ugly (Michaela Brchnelova) 
URL;VALUE=URI:https://www.mps.mpg.de/events/32565/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/36203/7840847
DTSTART:20231130T100000Z
DTEND:20231130T110000Z
CLASS:PUBLIC
CREATED:20231128T081727Z
DESCRIPTION:The solar corona temperature is maintained to more than 1 MK. O
 ne of the main theories of the coronal formation (Parker 1988) suggests th
 at the energy is dissipated into the corona through a high number of impul
 sive\, low energy (10²⁴ ergs) heating events\, called “nanoflares”.
  On 30 May 2020\, during its first high temporal and spatial resolutions o
 bservations\, 1463 small (400 – 4000 km) and short lived (10-100 s) EUV 
 brightenings were detected in the Quiet Sun by the high resolution UV imag
 er HRI-EUV (174 Å) on board Solar Orbiter. These may be the signatures of
  nanoflare heating. As HRI-EUV is sensitive to both coronal and transition
  region emission\, our goal is to verify if these brightenings indeed do r
 each coronal temperatures. As spectroscopic data were not available during
  the 2020 May observation\, we applied the time lag method to the SDO/AIA 
 coronal channels. The objective is to infer the thermal behavior of the ev
 ents. Our results suggest two possible interpretations: either (1) the eve
 nts peak below 1 MK\, where the AIA response functions behave similarly\, 
 or (2) the events cooling time scale is below the AIA cadence of 12s. As s
 pectroscopic observations should be able to clearly distinguish between bo
 th cases\, we then use cotemporal Quiet Sun observations of Solar Orbiter 
 HRI-EUV and SPICE\, coordinated with Hinode/EIS\, on 8 and 17 March 2022\,
  and on 4 April 2023. We first detect the events in HRI-EUV\, and identify
  them in SPICE or EIS. Temperature diagnostics using SPICE or EIS data con
 firm that these events are dominated by plasma below coronal temperatures.
  We conclude that these small (&lt\; 4 Mm) EUV brightenings detected by HR
 I-EUV are dominated by plasma at chromospheric or transition region temper
 ature. As such\, they hardly contribute directly to coronal heating.\nSpea
 ker: Antoine Dolliou
LAST-MODIFIED:20231128T083511Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS - European Solar Physics Online Seminar: Small EUV bri
 ghtenings detected by HRI-EUV on board Solar Orbiter: estimation of their 
 termperature with SDO/AIA\, Solar Orbiter/SPICE and Hinode/EIS 
URL;VALUE=URI:https://www.mps.mpg.de/events/36203/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/36953/7840847
DTSTART:20240307T100000Z
DTEND:20240307T110000Z
CLASS:PUBLIC
CREATED:20240227T165920Z
DESCRIPTION:A new era of solar physics commences with observations of the q
 uiet Sun using the 4-metre Daniel K. Inouye Solar Telescope/Visible Spectr
 opolarimeter (DKIST/ViSP). We present full-Stokes observations taken durin
 g DKIST’s cycle 1\, in the Fe I 630.1/630.2 nm lines\, allowing us to ex
 amine small-scale magnetism in the photosphere. We use the Stokes Inversio
 n based on Response functions (SIR) code to invert the Fe I line pair. We 
 reveal the existence of a serpentine magnetic element for the first time. 
 A statistical analysis is undertaken\, comparing inversions of DKIST data 
 with Hinode data. A novel machine learning technique is used to characteri
 se and contrast the shapes of circular polarisation signals found in the g
 round-based and space-based data\, and synthetic observations produced fro
 m MANCHA simulations are used to aid our understanding of the differences 
 between datasets.\nSpeaker: Ryan Campbell
LAST-MODIFIED:20240227T170326Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS - DKIST's view of quiet photospheric magnetism and app
 lication of neural networks to the characterisation of Stokes profiles (R.
  Campbell)
URL;VALUE=URI:https://www.mps.mpg.de/events/36953/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/37171/7840847
DTSTART:20240321T100000Z
DTEND:20240321T110000Z
CLASS:PUBLIC
CREATED:20240318T194305Z
DESCRIPTION:The solar radiation in the cores of the Mg II h &amp\; k spectr
 al lines strongly correlates with solar magnetic activity and global varia
 tions of magnetic fields with the solar cycle. This work provides a data-d
 riven model of the temporal evolution of the solar full-disk Mg II h &amp\
 ; k profiles over the solar cycle. Based on selected 76 IRIS near-UV full-
 Sun mosaics covering almost the full solar cycle 24\, we find the paramete
 rs of double-Gaussian fits of the disk-averaged Mg II h &amp\; k profiles 
 and a model of their temporal evolution parameterized by the Bremen compos
 ite Mg II index. The Markov Chain Monte Carlo algorithm implemented in the
  IDL toolkit SoBAT is used in modeling and predicting the temporal evoluti
 on of the Mg II h &amp\; k peak-to-center intensity ratio and the Bremen M
 g II index. The relevant full-disk Mg II h &amp\; k calibrated profiles wi
 th uncertainties and spectral irradiances are provided as an online machin
 e-readable table. To facilitate the utilization of the model corresponding
  routines\, written in IDL\, are made publicly available on GitHub.Co-auth
 ors: Stanislav Gunár (The Czech Academy of Sciences\, Czech Republic)\, P
 avol Schwartz (Slovak Academy of Sciences\, Slovakia)\, Petr Heinzel (The 
 Czech Academy of Sciences\, Czech Republic\; University of Wrocław\, Pola
 nd)\, Wenjuan Liu (The Czech Academy of Sciences\, Czech Republic)\nSpeake
 r: Julius Koza
LAST-MODIFIED:20240318T194837Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS -Data-driven mode l of temporal evolution of the solar
  Mg II h and k profiles over the solar cycle (J. Koza) 
URL;VALUE=URI:https://www.mps.mpg.de/events/37171/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/37252/7840847
DTSTART:20240404T090000Z
DTEND:20240404T100000Z
CLASS:PUBLIC
CREATED:20240322T173311Z
DESCRIPTION:The solar atmosphere is filled with clusters of hot small-scale
  loops commonly known as Coronal Bright Points (CBPs). These ubiquitous st
 ructures stand out in the Sun by their strong X-ray and/or extreme ultravi
 olet (EUV) emission for hours to days\, which makes them a crucial piece w
 hen solving the solar coronal heating puzzle. Here we present a novel 3D n
 umerical model using the Bifrost code that explains the sustained CBP heat
 ing for several hours. We find that stochastic photospheric convective mot
 ions alone significantly stress the CBP magnetic field topology\, leading 
 to important Joule and viscous heating concentrated around the CBP’s inn
 er spine at a few megameters above the solar surface. We validate our mode
 l by comparing simultaneous CBP observations from SDO and SST with observa
 ble diagnostics calculated from the numerical results for EUV wavelengths 
 as well as for the Halpha line using the Multi3D synthesis code. Co-author
 s: Fernando Moreno-Insertis\, Klaus Galsgaard\, Kilian Krikova\, Luc Roupp
 e van der Voort\, Reetika Joshi\, and Maria Madjarska\nSpeaker: Daniel Nó
 brega-Siverio
LAST-MODIFIED:20240322T173549Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS - Deciphering solar coronal heating: Energizing small-
 scale loops through surface convection (D. Nóbrega-Siverio)
URL;VALUE=URI:https://www.mps.mpg.de/events/37252/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/37474/7840847
DTSTART:20240418T090000Z
DTEND:20240418T100000Z
CLASS:PUBLIC
CREATED:20240415T170801Z
DESCRIPTION: I briefly review some methods and measurements of elemental ab
 undances in the solar atmosphere\, with emphasis on the transition region 
 and corona. Some limitations in the methods\, in the modeling of the spect
 ral line intensities\, and the observations are discussed. Examples from t
 he X-rays\, the EUV\, the UV\, the visible\, and near-infrared are present
 ed. A significant improvement in the modeling of some of the ions is being
  made available with CHIANTI version 11. All the observations indicate tha
 t the solar corona has photospheric abundances and that the hot 3 MK activ
 e region cores have stable enhancements of a factor of about 3.2 in the ra
 tios of low to high-FIP elements. A lot of uncertainties and puzzles still
  exist\, requiring further analyses and\, more importantly\, future instru
 mentation.\nSpeaker: Giulio Del Zanna
LAST-MODIFIED:20240415T171003Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS - Thoughts on measuring elemental abundances in the so
 lar atmosphere (G. Del Zanna)
URL;VALUE=URI:https://www.mps.mpg.de/events/37474/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/37650/7840847
DTSTART:20240502T090000Z
DTEND:20240502T100000Z
CLASS:PUBLIC
CREATED:20240428T112411Z
DESCRIPTION: We present the results of coordinated observations of the Swed
 ish 1-m Solar Telescope with Solar Orbiter that took place from October 12
 th to 26th 2023. The campaign resulted in 7 datasets of various quality. T
 he observational programs were adjusted to the seeing conditions. The obse
 rvations cover two active regions and a coronal hole. We focus on the morp
 hology and evolution of several targets that are observed from two vantage
  points. We share the lessons we learned and give an outline of our plans 
 for October this year and the support we could give during remote sensing 
 windows 16 and 17.\nSpeaker: Sanja Danilovic
LAST-MODIFIED:20240428T112557Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS - An overview of last October's SST-SolO observational
  campaign (S. Danilovic)
URL;VALUE=URI:https://www.mps.mpg.de/events/37650/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/38264/7840847
DTSTART:20240530T090000Z
DTEND:20240530T100000Z
CLASS:PUBLIC
CREATED:20240529T064119Z
DESCRIPTION:Observations of small-scale brightenings in the low solar atmos
 phere can provide valuable constraints on possible heating and heat transp
 ort mechanisms. We present a method for the detection and analysis of brig
 ht points (BPs)\, and demonstrate its application to time-series imagery o
 f the Interface Region Imaging Spectrograph (IRIS) in the extreme ultravio
 let. The method is based on spatio-temporal band-pass filtering\, adaptive
  thresholding and centroid tracking\, and records an event’s spatial pos
 ition\, duration\, speed\, total brightness\, maximum brightness\, and int
 rinsic brightness. Spatial area\, brightness\, and position are also recor
 ded as functions of time throughout the event’s lifetime. Detected brigh
 tenings can fragment\, or merge\, over time – thus the number of distinc
 t regions constituting a brightening event is recorded over time\, and the
  maximum number of regions recorded as Nfrag\, which is a simple measure o
 f an event’s coherence or spatial complexity. The method is first tested
  on synthetic data based on Poisson statistics before being applied to rea
 l IRIS data. We present statistical characteristics of brightenings from t
 he application of this method to 1330\, 1400\, and 2796 Å IRIS slit-jaw i
 mage time series. Several thousand events are recorded that coexist in all
  three channels\, giving high confidence that they are real. Finally\, we 
 will also present continuing applications of this detection method to anal
 yse a large set of BPs and their characteristics – over 12\,000 BPs in t
 otal – and compare those that are found within ‘Active’ and ‘Quiet
 ’ domains within a QS region\, as well as possible future applications o
 f the detection method.\nSpeaker: Llŷr Dafydd Humphries
LAST-MODIFIED:20240529T064515Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS - Detection and in-depth analyses of quiet-Sun IRIS Br
 ight Points (Llŷr Dafydd Humphries)
URL;VALUE=URI:https://www.mps.mpg.de/events/38264/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/38303/7840847
DTSTART:20240613T090000Z
DTEND:20240613T100000Z
CLASS:PUBLIC
CREATED:20240605T065106Z
DESCRIPTION:It is well understood that the dynamics of sunspots lead to ene
 rgy being transferred to the solar atmosphere and stored in the coronal ma
 gnetic field. This provides a surplus of energy that may be released in so
 lar eruptions. The driving mechanisms for this energy transfer may include
  sunspot rotations\, both within individual sunspots and between sunspot p
 airs. Calculation of the rotations of individual sunspots have been carrie
 d out by several authors\, but studies of the rotation of sunspot pairs ha
 s been less systematically investigated.Calculation of rotations in either
  case rely on careful tracking of the sunspots from observation to observa
 tion. Identification and tracking of sunspots is therefore essential to un
 derstanding the energies in play that lead up to solar eruptions. To date\
 , this has predominantly been done manually which has restricted many stud
 ies to being a small number of case studies rather than large statistical 
 samples. In order to construct large samples\, the careful tracking of sun
 spots must be automated.We present a fully automatic method to identify an
 d track sunspots in long sequences of data from the Solar Dynamics Observa
 tory Helioseismic and Magnetic Imager (SDO/HMI) at a high temporal resolut
 ion. This includes registering the splitting and merging of sunspots\, and
  allocating sunspots to active regions. This information can be fed into a
 lgorithms to measure the rotation of individual sunspots or used to calcul
 ate the relative motion of sunspots with respect to each other (including 
 co-rotation).The method is applied to a four-month data set that has previ
 ously been analysed using a semi-automatic method where the basic sunspots
  were identified by eye\, and the results are compared to determine any di
 fferences between the methods. From this data\, sunspot dynamics such as s
 unspot rotation\, shearing and merging are calculated\, alongside sunspot 
 pair interactions. Case studies of successfully tracked sunspots will be p
 resented\, showing examples of the individual sunspot rotations and some i
 nitial results involving sunspot pair interactions with correlations to so
 lar activity.\nSpeaker: Charlotte Proverbs
LAST-MODIFIED:20240605T065255Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS -Automatic Identification and Tracking of Sunspots (Ch
 arlotte Proverbs)
URL;VALUE=URI:https://www.mps.mpg.de/events/38303/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/38437/7840847
DTSTART:20240627T090000Z
DTEND:20240627T100000Z
CLASS:PUBLIC
CREATED:20240620T064553Z
DESCRIPTION:The prediction of geomagnetic storms is becoming more and more 
 important\, with the aim to take effective measures for avoiding the possi
 ble damage from the extreme events. One of the important parameters when m
 odeling CMEs and CME-driven shocks\, is their arrival time at Earth. We pr
 esent a study of several halo CMEs with the propagation direction which si
 gnificantly deviated from the Sun-Earth line and as a result\, CMEs impact
 ed Earth as flank-encounters. We modeled selected events with the default-
 setup of EUHFORIA and the Cone model for the CMEs. The aim of our study is
  to better understand the importance of the CME’s direction of propagati
 on in the input parameters of the Cone model and improve the modeled arriv
 al time at Earth. We selected events that were propagating strongly non-ra
 dialy in the low corona\, in order to understand how important are the eff
 ects of the deflections in the low corona\, in the direction of propagatio
 n. Our results show that\, when the data from the DONKI database are used\
 , the modeled arrival time has the largest discrepancy(≥10h) when compar
 ed with observations. When the input parameters are taken employing the GC
 S fitting technique though\, up to the height of 12 Ro (solar radii)\, the
  accuracy of the modeled arrival time improves\, shifting closer to the ob
 served ones. This result reflects the characteristic that\, up to the heig
 hts of about 10 Ro\, CMEs experience all the low coronal deflections and h
 ave taken their final direction of propagation.\nSpeaker: Charlotte Prover
 bs
LAST-MODIFIED:20240620T064807Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS - Modeling of non-radially propagating halo CMEs and f
 orecasting their arrival time at Earth(Angelos Valentino)
URL;VALUE=URI:https://www.mps.mpg.de/events/38437/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/39048/7840847
DTSTART:20240905T090000Z
DTEND:20240905T100000Z
CLASS:PUBLIC
CREATED:20240901T160720Z
DESCRIPTION: Strong magnetic skew characterizes several non-potential struc
 tures in the solar corona\, including filaments\, which can erupt\, bringi
 ng about major geomagnetic effects. Skew is thus an indicator of the forma
 tion of filament channels and a useful property in making forecasts from g
 lobal coronal models. For skew to be used in this way\, its formation and 
 evolution must be identified\, with particular consideration of when this 
 occurs within the field of view observable from Earth. Magnetofrictional s
 imulations are performed\, with the photospheric boundary condition provid
 ed by an observed flux distribution. New techniques are presented for iden
 tifying where strong skew forms\, and the production and persistence of st
 rong skew in the corona studied systematically. Strong skew is found to fo
 rm incrementally\, in small patches\, especially around recently emerged b
 ipolar regions. As such\, skew is produced and persists over very long per
 iods of time\, comparable with the timescale for solar rotation. Consequen
 tly\, most skew on the Earth-facing side of the Sun rotates onto it\, havi
 ng formed on the far side\, rather than forming within the Earth’s field
  of view. Therefore\, in a data-driven model that is limited to including 
 the emergence of flux observed only from Earth\, most of the resultant ske
 w will form after this flux has rotated out of view and onto the far side 
 of the Sun. Given this\, it will be important to study how a wider field o
 f view for capturing emergent flux before it rotates into longitudes visib
 le from Earth\, afforded by multi-viewpoint observations\, would improve o
 ur capacity to model and predict Earth-facing phenomena on the Sun\, which
  are important for space weather. Possible effects of multi-viewpoint obse
 rvations on similar models of the formation of skew are considered. Co-aut
 hors: D. H. Mackay\, and L. A. Upton\nSpeaker: Jack Reid 
LAST-MODIFIED:20240901T161023Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS -Quantifying when and where strong magnetic skew forms
  in a data-driven global model of the solar corona when limited observatio
 nal data exist (J. Reid) 
URL;VALUE=URI:https://www.mps.mpg.de/events/39048/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/39191/7840847
DTSTART:20240919T090000Z
DTEND:20240919T100000Z
CLASS:PUBLIC
CREATED:20240915T111123Z
DESCRIPTION: Solar observations have often served as benchmarks of stellar 
 conditions. A particularly illustrative example of the above link is given
  by the observations in the Ca II K and H lines at 393.367 nm and 396.847 
 nm\, respectively\, which are the two deepest and broadest absorption line
 s in the visible spectrum of the Sun. Although widely observed over the ye
 ars\, several aspects of the emission of these lines are however still not
  fully understood. This is the case of e.g. the exact relationship between
  Ca II K emission and magnetic field strength. To the aim of reassessing t
 his relationship\, we analyzed state-of-the-art observations of the solar 
 atmosphere obtained at the Swedish Solar Telescope with the CRisp Imaging 
 SPectropolarimeter and with the CHROMospheric Imaging Spectrometer on regi
 ons characterized by a different ambient magnetic field. On these observat
 ions we analyzed the dependence of the Ca II K line brightness\, as well a
 s the relationship between Ca II K emission and magnetic field strength on
  different surrounding conditions of the solar atmosphere and characterist
 ics of the observations\, such as spectral bandwidth and spatial scale. Th
 e data and methods employed\, and results achieved by our analysis will be
  presented\, with emphasis on their impact on the interpretation of previo
 us findings in the literature and application in future studies.\nSpeaker:
  Mariarita Murabito
LAST-MODIFIED:20240915T111556Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Ca II K brightness as a function of magnetic field st
 rength and characteristics of the observations (M. Murabito)
URL;VALUE=URI:https://www.mps.mpg.de/events/39191/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/39363/7840847
DTSTART:20241003T090000Z
DTEND:20241003T100000Z
CLASS:PUBLIC
CREATED:20240926T170228Z
DESCRIPTION: Sustained kink oscillations in coronal loops have long been ob
 served in TRACE\, SDO/AIA\, and more recently in SolO/EUI images. Although
  their properties are quite well-known now\, their driver and excitation m
 echanism remain under active debate. In this talk I will give an overview 
 over the different ideas/theories that discuss the role of photospheric dr
 iving in the generation of kink oscillations. We exploited an unique datas
 et of high-resolution coronal and photospheric observations taken recently
  by SolO/EUI/HRI and the Swedish 1-m Solar Telescope (SST) respectively du
 ring a dedicated coordinated campaign run in October 2023. Using the SST/C
 RISP data we estimated and quantified the strength of photospheric driving
  at the footpoints of active region coronal loops\, that include pore\, pl
 age\, enhanced-network and sunspot regions. We then looked at kink oscilla
 tion signatures in the same coronal loops within the EUI/HRI coronal image
 s. An attempt was then made to link the photospheric and coronal results t
 ogether. I will finally discuss the implications of this work on the drivi
 ng and excitation mechanism of kink oscillations\, and future perspectives
 .\nSpeaker: Nicolas Poirier
LAST-MODIFIED:20240926T170359Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Transverse oscillations in coronal loops and photosph
 eric driving: combining high-resolution coronal and photospheric diagnosti
 cs together (N. Poirier)
URL;VALUE=URI:https://www.mps.mpg.de/events/39363/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/39585/7840847
DTSTART:20241017T090000Z
DTEND:20241017T100000Z
CLASS:PUBLIC
CREATED:20241011T144417Z
DESCRIPTION: Solar filaments (also called prominences when seen off-disk) a
 re solar atmospheric structures consisting of dense\, cool plasma clouds f
 loating within the sun's corona. Since the beginning of solar observations
 \, it has been seen that the prominences oscillate with a wide variety of 
 motions. These periodic motions are very common\, but there are no systema
 tic studies of these oscillations. It has recently been shown that spectra
 l analysis of solar filaments is a powerful tool to identify oscillations 
 in these structures. With this technique\, the power spectral density (PSD
 ) is calculated for each pixel of the Halpha images. To differentiate betw
 een a detection or a spurious oscillation\, it is necessary to determine t
 he background noise. We have seen that this background noise is a combinat
 ion of red and white noise. The red-noise nature of the PSD is problematic
  in their study since most of the statistical tools developed to identify 
 real oscillations from the noise are for white-noise PSD. The most appropr
 iate approach for this problem is the usage of Bayesian statistics and Mon
 te Carlo Markov Chains (MCMC). MCMC methods can be computationally expensi
 ve and have been proven to be too slow for our research aims\, so we tackl
 e this problem with deep learning techniques\, specifically Convolutional 
 Neural Networks (CNNs). We developed two neural networks\, which reproduce
  the same outcomes as the MCMC methods. Both have been trained with synthe
 tic data as well as real data from the MCMC methods. The results obtained 
 show negligible differences with the results from the MCMC methods but wit
 h the advantage of computing times orders of magnitude smaller.\nSpeaker: 
 Guillem Castelló i Baceló
LAST-MODIFIED:20241011T144723Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Spectral analysis of solar filaments using Convolutio
 nal-Neural Networks (CNNs) (G. Castelló i Barceló)
URL;VALUE=URI:https://www.mps.mpg.de/events/39585/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/39710/7840847
DTSTART:20241031T100000Z
DTEND:20241031T110000Z
CLASS:PUBLIC
CREATED:20241026T151856Z
DESCRIPTION: Recent advancements in spectropolarimetric instrumentation\, s
 uch as the new facilities at the GREGOR and DKIST telescopes\, have genera
 ted vast amounts of data with each observation. This increase in data volu
 me results in longer processing times heightened demands on computational 
 resources\, and an expanded carbon footprint\, complicating scientific dev
 elopment timelines. The numerical inversion codes used for data analysis\,
  based on radiative transfer models\, are inherently complex. Modern proje
 cts focused on the solar atmosphere and its magnetic field require additio
 nal assumptions\, significantly increasing processing times for each pixel
 . To address this challenge\, new methods are being developed\, leveraging
  modern data processing algorithms from statistics and machine learning. W
 e are testing a 1D convolutional neural network model inspired by the 1D p
 arallel atmosphere model of radiative transfer to enhance spectropolarimet
 ric inversions and achieve significant reductions in processing times\, as
  demonstrated in previous studies. Our approach aims to integrate physical
  constraints into the learning process\, allowing the model to not only re
 plicate inversions but also gain insights into the underlying physics. The
  data for our project was synthesized using state-of-the-art codes for mag
 netohydrodynamics (MURaM) and radiative transfer under non-local thermodyn
 amic equilibrium (NICOLE). Preliminary results without physical constraint
 s show loss rates approaching 10-3 orders of magnitude and Pearson correla
 tions of the order of 0.8 on average along different optical depths invert
 ed in the process for thermodynamic quantities.\nSpeaker: Juan Esteban Agu
 delo 
LAST-MODIFIED:20241026T152124Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Solar spectropolarimetric inversions applying Deep Le
 arning techniques (Juan Esteban Agudelo) 
URL;VALUE=URI:https://www.mps.mpg.de/events/39710/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/39824/7840847
DTSTART:20241114T100000Z
DTEND:20241114T110000Z
CLASS:PUBLIC
CREATED:20241110T140415Z
DESCRIPTION: Small solar flares\, or microflares (GOES B class and fainter)
 \, are frequent bursts of energy released in the Sun’s atmosphere\, exhi
 biting heating and particle acceleration similar to that of large flares. 
 X-ray observations provide direct diagnostics to study these processes by 
 examining thermal emission from the hot flare loops and non-thermal emissi
 on from accelerated electrons. We present analysis of the X-ray emission f
 rom small solar flares jointly observed with the Nuclear Spectroscopic Tel
 escope Array (NuSTAR) and the Spectrometer Telescope for Imaging X-rays (S
 TIX) on Solar Orbiter\, providing different viewing angles of each event. 
 NuSTAR is a highly sensitive X-ray imaging spectrometer that can directly 
 image the Sun from 2.5 keV using focusing optics. STIX is an imaging spect
 rometer which instead uses indirect optics but has detectors capable of ha
 ndling a wide range of solar X-ray fluxes from 4 to 150 keV. NuSTAR is in 
 Earth orbit\, whereas STIX is orbiting the Sun\, so the two instruments co
 mbined can give different viewing angles of solar X-ray emission\, providi
 ng a clearer picture of the flare’s structure. Combining analysis of NuS
 TAR and STIX’s X-ray spectra\, we can take advantage of their different 
 strengths\, gaining a better understanding of the energy release in solar 
 flares. We present observations of flares from June 2020 (on-disk for both
  instruments) and September 2022 (occulted for NuSTAR but on-disk for STIX
  - allowing us to probe a pre-flare non-thermal coronal source with NuSTAR
  and bright lower atmosphere flare emission with STIX).\nSpeaker: Natalia 
 Bajnokova
LAST-MODIFIED:20241110T140718Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: First joint NuSTAR and Solar Orbiter/STIX X-ray obser
 vations of solar microflares
URL;VALUE=URI:https://www.mps.mpg.de/events/39824/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/40023/7840847
DTSTART:20241114T100000Z
DTEND:20241114T110000Z
CLASS:PUBLIC
CREATED:20241124T125205Z
DESCRIPTION: Magnetic reconnection and turbulence are two phenomena that ar
 e often invoked to address outstanding open questions as the energy dissip
 ation problem and the heating and acceleration of the solar wind. These tw
 o phenomena are closely related to each other in a wide range of plasmas. 
 Turbulent fluctuations can emerge in critical regions of reconnection even
 ts\, and magnetic reconnection can occur as a product of the turbulent cas
 cade. In this seminar I present some results exploring the interlink betwe
 en turbulence and reconnection. This talk is divided in two sections\, the
  first one Exploring the Effect of Driving Turbulent-like Fluctuations on 
 a Harris Current Sheet Configuration and the Formation of Plasmoids and th
 e second one Characterising Sub-Grid-Scale Effects on the Ohms Law Terms i
 n Hybrid Simulations of Turbulence at the Earth’s Magnetosheath. The con
 necting thread is the non-linear and multi-scale nature of turbulence and 
 reconnection as well as the importance of the small-scale dynamics on the 
 large-scale one. In the first study\, we perform 2D particle-in-cell simul
 ations of a reconnecting Harris current sheet in the presence of turbulent
  fluctuations to explore the effect of turbulence on the reconnection proc
 ess in collisionless non-relativistic pair-plasmas. We find that the prese
 nce of a turbulent field can affect the onset and evolution of magnetic re
 connection. Moreover\, we observe the existence of a scale dependent ampli
 tude of magnetic field fluctuations above which these fluctuations can dis
 rupt the growing of magnetic islands. These fluctuations provide thermal e
 nergy to the particles within the current sheet and preferential perpendic
 ular thermal energy to the background population. In our second study we a
 ddress the challenge that poses the modelling of large-scale systems while
  accounting for the small-scale phenomena by characterising the contributi
 on of the small-scale dynamic terms on the generalized Ohms law in Vlasov-
 Hybrid simulations of turbulence in Earth’s magnetosheath. This with the
  aim of providing insight on Sub-Grid-Scale models that can be incorporate
 d in Large Eddy Simulations. Our results are highly relevant to the future
  modelling of large-scale turbulent plasmas such as magnetospheres\, the s
 olar wind\, the solar atmosphere\, and other astrophysical systems.\nSpeak
 er: Jeffersson Agudelo Rueda 
LAST-MODIFIED:20241124T125430Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Turbulence and reconnection: exploring the role of ki
 netic fluctuations on the formation of plasmoids in a current sheet and ho
 w to include small-scale phenomena on large-scale systems (Jeffersson Agud
 elo Rued) 
URL;VALUE=URI:https://www.mps.mpg.de/events/40023/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/40562/7840847
DTSTART:20250130T100000Z
DTEND:20250130T110000Z
CLASS:PUBLIC
CREATED:20250126T213830Z
DESCRIPTION: Stellar flares cannot be spatially resolved\, which means that
  we have to extract complex three-dimensional behavior from a one-dimensio
 nal disk-integrated spectrum. Due to their proximity to Earth\, solar flar
 es can serve as a stepping stone for understanding their stellar counterpa
 rts\, especially when using a Sun-as-a-star instrument in combination with
  spatially resolved observations. In this talk I will discuss a confined X
 2.2 flare and its eruptive X9.3 successor as measured by the HARPS-N Sun-a
 s-a-star telescope. The behavior of multiple photospheric and chromospheri
 c spectral lines are investigated by means of activity indices and contras
 t profiles\, which are then related to physical processes directly observe
 d in high-resolution observations made with the Swedish 1-meter Solar Tele
 scope (SST). We further explore these relations by using the newly develop
 ed Numerical Sun-as-a-Star Integrator (NESSI) code to convert high-resolut
 ion SST flares to full disk spectra. Our findings suggest a relationship b
 etween the evolving shapes of the disk integrated spectra and the flare lo
 cations on the solar disk\, which could be act as a guide for constraining
  flare locations in stellar spectra.\nSpeaker: Alex Pietrow
LAST-MODIFIED:20250126T214139Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Sun-as-a-star flare observations with HARPS-N and SST
  (Alex Pietrow)
URL;VALUE=URI:https://www.mps.mpg.de/events/40562/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/40773/7840847
DTSTART:20250213T100000Z
DTEND:20250213T110000Z
CLASS:PUBLIC
CREATED:20250209T103907Z
DESCRIPTION: In the recent decades\, three-dimensional modelling of solar f
 lares and eruptions has made a number of predictions that were subsequentl
 y indicated by high-resolution imaging observations. These include existen
 ce of magnetic reconnection geometries involving the erupting flux rope it
 self\, which drifts as a result\, and also the apparent slipping and slip-
 running motion of footpoints of individual reconnecting structures. In thi
 s talk\, we will summarize the predictions of the MHD models as well as th
 e corroborating evidence\, with particular emphasis on recent observations
  of super-Alfvénic slippage of flare kernels.\nSpeaker: Jaroslav Dudík 
LAST-MODIFIED:20250209T104202Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Three dimensional magnetic reconnection: Theory and o
 bservations (Jaroslav Dudík)
URL;VALUE=URI:https://www.mps.mpg.de/events/40773/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/41018/7840847
DTSTART:20250227T100000Z
DTEND:20250227T110000Z
CLASS:PUBLIC
CREATED:20250221T152639Z
DESCRIPTION: The Sun is a dynamic star\, displaying activities ranging from
  subtle\, short-lived events to major coronal mass ejections (CMEs) and po
 werful flares. Differentiating between “flaring” and “non-flaring”
  active region (AR) configurations is critical for heliophysics research. 
 This study investigates whether small to medium-scale activity in ARs hold
 s clues about their eruptive potential and future behaviour. Using data fr
 om the Atmospheric Imaging Assembly (AIA) and the Helioseismic and Magneti
 c Imager (HMI) onboard the Solar Dynamics Observatory (SDO)\, we analyse t
 ransient brightenings and their relationship to the magnetic polarity inve
 rsion line (PIL) in ARs. We observe significant differences between pre-fl
 aring and non-flaring ARs in terms of the spatial distribution and tempora
 l evolution of transient brightenings around the PIL. Key parameters inclu
 de the number\, intensity\, and magnetic flux of brightenings over time\, 
 as well as their behaviour across multiple wavelengths. These variations o
 ffer insights into the Sun’s atmospheric dynamics and the mechanisms dri
 ving major flares and – in case of coronal mass ejections – eruptions.
  By understanding the pre-eruptive activity in ARs\, we aim to improve sol
 ar event prediction capabilities and advance our knowledge of the relevant
  dynamics.\nSpeaker: Augustin André-Hoffmann
LAST-MODIFIED:20250221T152844Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: How BRADPIT could help us in flare forecasting throug
 h small AR activity monitoring (Augustin André-Hoffmann)
URL;VALUE=URI:https://www.mps.mpg.de/events/41018/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/41141/7840847
DTSTART:20250313T100000Z
DTEND:20250313T110000Z
CLASS:PUBLIC
CREATED:20250306T140410Z
DESCRIPTION:On October 28\, 2021 the first X-class solar flare of Solar Cyc
 le 25 occurred in active region NOAA AR 12887 with a peak at 15:35 UT. It 
 produced the rare event of ground-level enhancement of the solar relativis
 tic proton flux and a global extreme ultraviolet wave\, along with a fast 
 halo coronal mass ejection (CME) as seen from Earth’s perspective. A few
  hours before the flare\, a slower CME had erupted from a quiet Sun region
  just behind the northwestern solar limb. Solar Orbiter was almost aligned
  with the Sun-Earth line and\, during a synoptic campaign\, its coronagrap
 h Metis detected the two CME events in both Visible Light (VL) and UltraVi
 olet (UV) channels. The earlier CME took place in the north-west (NW) sect
 or of Metis field of view\, while several bright features of the flare-rel
 ated event appeared mostly to the south-east (SE). The NW and SE events ha
 ve two distinct origins\, but were both characterized by a very bright emi
 ssion in HI Ly-alpha visible in the UV images of Metis up to 8 solar radii
 . This work is a follow-up study of two out of the six events analyzed by 
 Russano et al. 2024 (A&amp\;A\, 683\, A191)\, aimed at investigating the e
 volution of these two almost co-temporal CMEs but originating in such dist
 inct source regions. To that end\, we extensively inspect data sets from n
 umerous remote-sensing instruments observing the Sun in several spatial an
 d spectral regimes. We characterize several aspects of these CMEs\, includ
 ing their three-dimensional properties\, kinematics\, mass\, and temporal 
 evolution of those quantities. Results of this work point to notable diffe
 rences between these two events showing significant UV emission in the cor
 ona. Co-authors: H. Cremades\, F. A. Iglesias\, L. Teriaca\, R. Aznar Cuad
 rado\, F. M. López\, L. Di Lorenzo\, M. Temmer\, M. Romoli\, D. Spadaro\,
  and the Metis Team\nSpeaker: Yara De Leo
LAST-MODIFIED:20250306T140833Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Two Distinct Eruptive Events Observed by Metis on Oct
 ober 28\, 2021 (Yara de Leo)
URL;VALUE=URI:https://www.mps.mpg.de/events/41141/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/41511/7840847
DTSTART:20250313T100000Z
DTEND:20250313T110000Z
CLASS:PUBLIC
CREATED:20250404T172058Z
DESCRIPTION:On October 28\, 2021 the first X-class solar flare of Solar Cyc
 le 25 occurred in active region NOAA AR 12887 with a peak at 15:35 UT. It 
 produced the rare event of ground-level enhancement of the solar relativis
 tic proton flux and a global extreme ultraviolet wave\, along with a fast 
 halo coronal mass ejection (CME) as seen from Earth’s perspective. A few
  hours before the flare\, a slower CME had erupted from a quiet Sun region
  just behind the northwestern solar limb. Solar Orbiter was almost aligned
  with the Sun-Earth line and\, during a synoptic campaign\, its coronagrap
 h Metis detected the two CME events in both Visible Light (VL) and UltraVi
 olet (UV) channels. The earlier CME took place in the north-west (NW) sect
 or of Metis field of view\, while several bright features of the flare-rel
 ated event appeared mostly to the south-east (SE). The NW and SE events ha
 ve two distinct origins\, but were both characterized by a very bright emi
 ssion in HI Ly-alpha visible in the UV images of Metis up to 8 solar radii
 . This work is a follow-up study of two out of the six events analyzed by 
 Russano et al. 2024 (A&amp\;A\, 683\, A191)\, aimed at investigating the e
 volution of these two almost co-temporal CMEs but originating in such dist
 inct source regions. To that end\, we extensively inspect data sets from n
 umerous remote-sensing instruments observing the Sun in several spatial an
 d spectral regimes. We characterize several aspects of these CMEs\, includ
 ing their three-dimensional properties\, kinematics\, mass\, and temporal 
 evolution of those quantities. Results of this work point to notable diffe
 rences between these two events showing significant UV emission in the cor
 ona. Co-authors: H. Cremades\, F. A. Iglesias\, L. Teriaca\, R. Aznar Cuad
 rado\, F. M. López\, L. Di Lorenzo\, M. Temmer\, M. Romoli\, D. Spadaro\,
  and the Metis Team\nSpeaker: Fallon Konow
LAST-MODIFIED:20250404T172416Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Two Distinct Eruptive Events Observed by Metis on Oct
 ober 28\, 2021 (Yara de Leo)
URL;VALUE=URI:https://www.mps.mpg.de/events/41511/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/41338/7840847
DTSTART:20250327T100000Z
DTEND:20250327T110000Z
CLASS:PUBLIC
CREATED:20250320T190312Z
DESCRIPTION:Solar Ultraviolet Imaging Telescope (SUIT) is the near Ultravio
 let imager (200-400 nm) on board the Indian Solar mission Aditya-L1. It wa
 s launched on September 2nd\, 2023 and was inserted in a halo orbit around
  the Earth-Sun L1 point on January 6th\, 2024. It has been regularly obser
 ving the Sun during its cruise phase and nominal observation time in the p
 ast year. Here\, we will present some of the selected flare observations c
 arried out by SUIT in the past year\, combining them with various multi-wa
 velength observations and highlighting the unique observation window SUIT 
 opens up in the lower solar atmosphere.\nSpeaker: Soumya Roy
LAST-MODIFIED:20250320T190513Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: First flare observations from SUIT (Soumya Roy)
URL;VALUE=URI:https://www.mps.mpg.de/events/41338/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/41549/7840847
DTSTART:20250410T090000Z
DTEND:20250410T100000Z
CLASS:PUBLIC
CREATED:20250409T155242Z
DESCRIPTION: We present a new network for space weather observation: Global
  Automatic Telescopes Exploring the SUN (GATES). GATES currently utilizes 
 two primary instruments: the Mojave Solar Observatory (MSO)\, located in A
 pple Valley\, California\, and the Tor Vergata Solar Synoptic Telescope (T
 SST)\, which is undergoing testing at the optical bench of the Università
  degli Studi di Roma Tor Vergata heliostat\, prior to its planned deployme
 nt to La Palma\, Canary Islands\, Spain. TSST consists of a dual-channel f
 ull disk telescope\, a lab-tested K magneto-optical filter (MOF) channel a
 nd a Hα channel for flare detection and localization. MSO houses a dual N
 a and K channel MOF-based telescope currently able to observe on-sky. With
  the completion and installation of the TSST\, the two nodes will observe 
 for an average of 20 hours a day\, obtaining line-of-sight velocity and ma
 gnetic field vector observations (Dopplergrams and magnetograms\, respecti
 vely)\, which we will use to analyze and predict space weather events. We 
 present preliminary data obtained using the network’s individual nodes a
 nd technical specifications for the future operation of the network as a w
 hole.\nSpeaker: Fallon Konow
LAST-MODIFIED:20250409T155415Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: GATES: A New Network for Synoptic Space Weather Obser
 vation (Fallon Konow) 
URL;VALUE=URI:https://www.mps.mpg.de/events/41549/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/41636/7840847
DTSTART:20250424T090000Z
DTEND:20250424T100000Z
CLASS:PUBLIC
CREATED:20250420T133117Z
DESCRIPTION: Spectral resolution and sampling present a design trade-off wh
 en building spectropolarimetric instruments to observe the Sun with very h
 igh spatial resolution. On the one hand\, for spectropolarimetric inversio
 ns\, high spectral resolution translates into a high depth resolution alon
 g the line of sight. On the other hand\, fine spectral sampling results in
  increased noise per wavelength bin\, smaller spectral ranges\, and higher
  data rates. In this talk\, we will explore how a finite spectral resoluti
 on changes the information content in stellar spectra. We do that by synth
 esizing spectra of the two magnetically sensitive photospheric lines of ir
 on around 630 nm and applying various spectral degradations and rebinning.
  We analyze how the dimensionality of the spectra changes and the performa
 nce of the spectropolarimetric inversions applied to these different synth
 etic datasets. We are especially interested in the effects of noise on the
  inferred parameters. We conclude that the fine spectral resolution (and h
 igh spectral fidelity) result in excellent inversions\, even at nominally 
 high noise levels. We support these conclusions with a few examples from T
 RIPPEL-SP and MiHI instruments at the Swedish Solar Telescope.\nSpeaker: I
 van Milic
LAST-MODIFIED:20250420T133347Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Spectral resolution effects on the information conten
 t in solar spectra (Ivan Milic)
URL;VALUE=URI:https://www.mps.mpg.de/events/41636/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/41741/7840847
DTSTART:20250508T090000Z
DTEND:20250508T100000Z
CLASS:PUBLIC
CREATED:20250503T153533Z
DESCRIPTION:Measuring the long-term variability of solar EUV/UV irradiances
  is needed for e.g. studying the Sun’s influence on space weather\, sate
 llite drag and for solar studies. However\, direct measurements remain lim
 ited\, making predictive modelling crucial. We have found linear correlati
 ons between EUV daily spectral irradiances obtained from SOHO/CDS and SDO/
 EVE and solar proxies of activity\, such as the F10.7\, F30 cm radio fluxe
 s and the Mg II index over several solar cycles\, analysing data from 1998
  until 2024. We confirm previous findings in that the F30 and the Mg II in
 dexes are better\, and that the variations increase with the formation tem
 perature of the lines\; the transition region lines show very little varia
 tions\, except the hydrogen and helium lines. A code to predict the EUV ir
 radiances of the main lines is provided. Relatively good agreement between
  the CDS and EVE irradiances is found\, but significant differences with h
 istorical measurements are found in some EVE lines\, especially at the lon
 ger wavelengths. Using the atomic data we made available in CHIANTI v.11 a
 nd the correlations with the proxies\, we are building a new model to pred
 ict the lines and continua in the whole EUV spectral range covered by SDO/
 EVE.\nSpeaker: Evangelia Deliporanidou
LAST-MODIFIED:20250503T153926Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Solar EUV irradiances\, their variations with the sol
 ar cycle and a new model (Evangelia Deliporanidou)
URL;VALUE=URI:https://www.mps.mpg.de/events/41741/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/41883/7840847
DTSTART:20250522T090000Z
DTEND:20250522T100000Z
CLASS:PUBLIC
CREATED:20250518T162942Z
DESCRIPTION: Kink oscillations of the decayless class are detected as small
  amplitude (&lt\; 1 Mm) persistent transverse repetitive displacements of 
 solar coronal plasma loops\, occurring without any association with solar 
 flares\, eruptions\, or other impulsive energy releases. The linear correl
 ation of the oscillation periods with the lengths of the oscillating loops
  demonstrates that the oscillations are natural modes of the loops. The st
 atistical distribution of oscillation amplitudes with the periods shows no
  pronounced peaks\, suggesting the lack of a periodic driver. Together wit
 h the lack of an impulsive excitation\, it suggests that the energy losses
  are compensated by the interaction of the loop with either quasi-steady o
 r random external plasma flows. In this study\, the decayless regime is as
 sociated with the energy supply from coronal plasma flows via the negative
  friction\, i.e.\, self-oscillations\, and/or random movements of footpoin
 ts of the oscillating loop. The damping is attributed to the linear effect
  of resonant absorption. Our low-dimensional model is based on a randomly 
 driven Rayleigh oscillator with random fluctuating coefficients. In the no
 iseless case\, the model has an asymptotically stationary oscillatory solu
 tion\, i.e.\, a self-oscillation. The kink oscillation period is found to 
 be practically independent of noise. Fluctuations of the amplitude envelop
 e are consistent with the observed behaviour. The transition from the larg
 e-amplitude rapidly-decaying regime to the low-amplitude decayless oscilla
 tions demonstrates that the decay pattern differs from the usually assumed
  exponential decay. An improved\, super-exponential model for the damping 
 is analytically derived and shown to be consistent with observations. In t
 he separately considered case of the decayless oscillatory regime supporte
 d by a random driver only\, the decay of the oscillation amplitude to the 
 decayless level is exponential. Implications of this finding for magnetohy
 drodynamic seismology of the solar corona\, based on the effect of resonan
 t absorption are discussed.\nSpeaker: Valery M Nakariakov 
LAST-MODIFIED:20250518T163300Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Decayless kink oscillations of solar coronal loops as
  a self-oscillatory process (Valery M Nakariakov) 
URL;VALUE=URI:https://www.mps.mpg.de/events/41883/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/42021/7840847
DTSTART:20250605T090000Z
DTEND:20250605T100000Z
CLASS:PUBLIC
CREATED:20250601T161403Z
DESCRIPTION: Spatial and temporal correlations of chromospheric fibrils and
  jets with the active region moss emission have been extensively studied s
 ince the beginning of this millennium\, suggesting a coupling between the 
 million-degree corona and the much cooler chromosphere\, both along the pe
 rpendicular to the field lines. We continued to investigate the interactio
 n between chromospheric fibrils and mossy active region plage under high s
 patial and temporal resolutions\, using the unique coordinated observation
 s made by Solar Orbiter\, the new NSF’s Daniel K. Inouye Solar Telescope
  (DKIST)\, and other near-Earth observatories on 24 October 2022. We ident
 ify apparent motions of fibrils observed in the Hα\, Hβ\, and Ca II K im
 ages obtained by the Visible Broadband Imager (VBI) on DKIST. Observations
  from the Slit-Jaw Imager (SJI) of the Interface Region Imaging Spectromet
 er (IRIS) and High Resolution Imager (HRI) telescope of the Extreme Ultrav
 iolet Imager (EUI) were used to search for potential counterparts of fibri
 l dynamics in the transition region and corona of the mossy plage. We also
  examine the alignment between the chromospheric fibrils and extrapolated 
 magnetic fields. This study paves the way for future investigations of chr
 omospheric dynamics using coordinated observations between Solar Orbiter a
 nd DKIST with its full suite of first-light instruments. We also outline a
 dditional scientific questions that such coordinated campaigns may help ad
 dress.\nSpeaker: Yingjie Zhu
LAST-MODIFIED:20250601T161544Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Chromospheric Fibrils in Pores and Mossy Active Regio
 n Plage Observed by DKIST\, IRIS\, and Solar Orbiter (Yingjie Zhu)
URL;VALUE=URI:https://www.mps.mpg.de/events/42021/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/42213/7840847
DTSTART:20250619T090000Z
DTEND:20250619T100000Z
CLASS:PUBLIC
CREATED:20250613T062958Z
DESCRIPTION: With the increase of space EUV observations (SoHO\, SDO\, Sola
 r Orbiter and soon the Vigil mission)\, this diagnostic has become an esse
 ntial tool to bridge the gap between models and our current understanding 
 of coronal phenomena. We will present a review of the recent studies using
  the Wind Predict model and its different versions\, which is a 3-dimensio
 n magnetohydrodynamic code to model the solar chromosphere\, corona and th
 e expansion of the solar wind. We will in particular discuss the influence
  of observations on the simulation results (with the question of spatial r
 esolution\, as well as the inclusion of far-side active regions observed b
 y Solar Orbiter)\, and vice-versa how the generation of synthetic data can
  help us improve our simulations (with the implementation of a feedback lo
 op based on automated coronal hole detection). Finally\, we will present t
 he next developments foreseen for the Wind Predict code.\nSpeaker: Barbara
  Perri
LAST-MODIFIED:20250613T063119Z
LOCATION:https://zoom.us/j/165498165
ORGANIZER;CN=Shahin Jafarzadeh:mailto:
SUMMARY:ESPOS: ESPOS: Wind Predict: Modeling the solar corona and its EUV e
 mission (Barbara Perri)
URL;VALUE=URI:https://www.mps.mpg.de/events/42213/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/43216/7840847
DTSTART:20251002T090000Z
DTEND:20251002T100000Z
CLASS:PUBLIC
CREATED:20250928T130609Z
DESCRIPTION:Energetic events such as solar flares and coronal mass ejection
 s (CMEs)\, which can lead to solar storms\, are driven by the coronal magn
 etic field (CMF)\, whose structure and evolution remain not fully understo
 od. When Earth-directed\, these storms can trigger auroras - as observed i
 n Portugal in 2024 - but also pose serious risks to radio communications\,
  GPS systems\, power grids\, and satellite infrastructure.Under certain co
 nditions\, Extreme Ultraviolet (EUV) observations reveal useful informatio
 n about the 3D geometry of some magnetic field lines\, as the emitting pla
 sma is "frozen into" the magnetic field\, though they do not provide measu
 rements of the magnetic field. Unlike the solar surface - the photosphere 
 - where the magnetic field can be measured via spectropolarimetry\, this i
 s generally not achievable in the typically force-free corona\, due to the
  faintness and thermal broadening of spectral lines. As a result\, extrapo
 lation methods are used to infer the coronal magnetic field from routine p
 hotospheric measurements.The most widely used model\, the Potential Field 
 Source Surface (PFSS)\, is fast and computationally efficient\, but it cal
 culates a current-free\, minimal-energy coronal field using the low measur
 ement uncertainty photospheric radial magnetic field component. This limit
 s its accuracy in active regions\, where magnetic free energy - critical f
 or flares and CMEs - is stored. More advanced\, state-of-the-art Non-linea
 r Force-Free Field (NLFFF) models allow for electric currents and\, theref
 ore\, free energy\, leading to greater accuracy\, but they are computation
 ally intensive and highly sensitive to data quality.We developed a signifi
 cantly faster Python code built upon a functional optimization framework p
 reviously proposed and implemented by our team. In this new version\, we i
 ntroduce a three-term functional that simultaneously minimizes: (1) the an
 gle between the magnetic field and the tangents to observed EUV loops\, (2
 ) the divergence of the magnetic field\, and (3) the Lorentz force. Includ
 ing the Lorentz-force term enables our method to control the degree of for
 ce-freeness\, an essential physical property typically accessible only to 
 the more computationally demanding NLFFF models.By minimizing the proposed
  functional\, we derive the perturbations that are iteratively applied to 
 the original PFSS solution. The resulting magnetic field represents a trad
 e-off between alignment with EUV loops\, solenoidality (divergence-freenes
 s)\, and force-freeness\, yielding a more physically realistic configurati
 on.This approach retains the computational efficiency of PFSS while signif
 icantly improving the physical consistency of the solution. Validation aga
 inst EUV observations confirms the method's ability to produce magnetic fi
 eld solutions that are more accurate and observationally constrained\, pro
 viding a new\, efficient\, and reliable tool for coronal magnetic field st
 udies.\nSpeaker: Carlos António
LAST-MODIFIED:20250928T132207Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Advancing Solar Magnetic Field Modeling (Carlos Antó
 nio)
URL;VALUE=URI:https://www.mps.mpg.de/events/43216/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/43217/7840847
DTSTART:20251016T090000Z
DTEND:20251016T100000Z
CLASS:PUBLIC
CREATED:20250928T131230Z
DESCRIPTION:Active regions with increasing magnetic complexity are more lik
 ely to trigger major solar eruptions. During a single solar cycle\, approx
 imately 1000 active regions emerge on the Sun. Among these\, about 250 dev
 elop magnetically complex configurations\, but only ~10% of them go on to 
 produce major eruptive events.This presentation addresses the challenge of
  bridging short- and medium-term analyses of solar magnetic field evolutio
 n to improve our ability to identify which of these complex active regions
  are most likely to erupt. Specifically\, we focus on how the location and
  magnetic evolution of these regions can help us isolate the small fractio
 n (~10%) of magnetically complex active regions that eventually produce ma
 jor eruptions.The analysis of the longitudinal distribution of these erupt
 ive active regions carried out builds on the concept of active longitudes\
 , as introduced in Kornél Császár’s earlier ESPOS talk in this semest
 er. In the second part of the talk\, we present studies of the magnetic fi
 eld evolution in the lower solar atmosphere for selected magnetically comp
 lex active regions that emerged within the identified active longitude ban
 d. Using approximately ten magnetic proxy parameters\, we examine how the 
 evolution of their structure provides insight into their eruptive potentia
 l.\nSpeaker: Marianna Korsos
LAST-MODIFIED:20250928T132118Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Localising and Mapping the Most Eruptive Regions on t
 he Sun (Marianna Korsos)
URL;VALUE=URI:https://www.mps.mpg.de/events/43217/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/43619/7840847
DTSTART:20251030T100000Z
DTEND:20251030T110000Z
CLASS:PUBLIC
CREATED:20251023T192614Z
DESCRIPTION: In July 2024\, Sunrise III flew from Sweden to Canada at strat
 ospheric heights capturing high resolution diffraction-limited images of t
 he Sun for 6.5 days. The telescope carried three scientific instruments ea
 ch complementing the other by observing in different parts of the solar sp
 ectrum from the near-ultraviolet by SUSI (309 nm - 417 nm)\, the visible b
 y TuMag (517 nm - 525 nm) to the near infrared by SCIP (765 nm - 855 nm). 
 During its flight\, Sunrise III observed a wide variety of features on the
  Sun including the quiet region\, sunspots\, plages\, filaments\, spicules
 \, flux emergence\, and also flares. By combining the data from the three 
 instruments\, it is possible to infer and understand various properties of
  the solar atmosphere from the photosphere to the upper chromosphere. In t
 his talk\, I will walk you through the Sunrise III journey\, the science p
 lanning\, present observational highlights and provide a glimpse into some
  of the exciting ongoing scientific analysis from the Sunrise III data.\nS
 peaker: Smitha Narayanamurthy
LAST-MODIFIED:20251023T192847Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Sunrise III Flight and Early Science Highlights (Smit
 ha Narayanamurthy)
URL;VALUE=URI:https://www.mps.mpg.de/events/43619/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/44097/7840847
DTSTART:20251127T100000Z
DTEND:20251127T110000Z
CLASS:PUBLIC
CREATED:20251206T145322Z
DESCRIPTION:During a solar flare\, fluxes in various lines and continua of 
 the solar spectrum increase\, causing enhanced ionisation in the illuminat
 ed part of the Earth’s ionosphere and an increase in the total electron 
 content (TEC). The dynamics of TEC driven by the impulsive phase of solar 
 flares have been studied extensively through both modelling and experiment
 al measurements. However\, the ionospheric effects of the late phase of so
 lar flares\, which occur in nearly half of X-class flares\, were discovere
 d only in 2024. This talk presents the results of the first multi-event st
 udy of the ionospheric response to the late phase of X-class solar flares.
  It also investigates how the flare’s location on the solar disk affects
  the ratio of ionospheric responses between the impulsive and late phases.
 \nSpeaker: Susanna Bekker
LAST-MODIFIED:20251206T145630Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Earth’s Ionospheric Response to the Impulsive and L
 ate Phases of Solar Flares (Susanna Bekker)
URL;VALUE=URI:https://www.mps.mpg.de/events/44097/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/43903/7840847
DTSTART:20251211T100000Z
DTEND:20251211T110000Z
CLASS:PUBLIC
CREATED:20251120T191040Z
DESCRIPTION: On 26 September 2022\, we observed a quiescent solar prominenc
 e with Hα imaging spectroscopy using the Solar Dynamics Doppler Imager (S
 DDI) on the SMART telescope. Unlike earlier works that detected 4- and 15-
 min oscillations through long-slit\, 1D wavelet methods\, we adapt the wav
 elet analysis to 3D data to explore the full prominence structure. Complem
 entary data from SDO/AIA (304 Å\, 171 Å) STEREO-A/EUVI (304 Å)\, and So
 lar Orbiter EUI/FSI (304 Å\, 174 Å) enable a multi-view\, multi-thermal 
 investigation of wave periodicity across the prominence. Our aim is to cha
 racterize how oscillatory periods are distributed in plasma at different t
 emperatures and viewing angles\, thereby assessing wave propagation and va
 riability throughout the prominence body.\nSpeaker: Aneta Wiśniewska
LAST-MODIFIED:20251206T150246Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Wave Period Variability in a Quiescent Solar Prominen
 ce (Aneta Wiśniewska) 
URL;VALUE=URI:https://www.mps.mpg.de/events/43903/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/44331/7840847
DTSTART:20260115T100000Z
DTEND:20260115T110000Z
CLASS:PUBLIC
CREATED:20260110T163118Z
DESCRIPTION: Coronal bright points are ubiquitous\, highly energetic events
  that are often seen accompanying other dynamic and eruptive phenomena in 
 the solar atmosphere. Their large energy output\, their similarity to acti
 ve regions and their connections to other events make them especially inte
 resting to understand the solar corona. This talk will describe the findin
 gs of a recent project focusing on the hottest loop constituents of corona
 l bright points. We extract and analyse the hot loops of three different s
 tate-of-the-art radiative-MHD Bifrost simulations\, studying their basic t
 hermodynamic\, magnetic and geometrical properties. The simulated loop pro
 perties are compared to a recent observational dataset\, the first detaile
 d study of this kind found in the literature\, finding great compatibility
  between simulations and observations. Additionally\, the loop geometry is
  assessed by focusing on the deviations from the commonly-assumed semi-cir
 cularity\, another aspect that has been overlooked so far. We study the he
 ating and cooling mechanisms acting on the loops\, a fundamental aspect to
  accurately model the energy balance of these structures and their contrib
 ution to the coronal heating. The results show that only the 3D simulation
 s show strong Joule and viscous heating in the footpoints. This reveals a 
 localized source of entropy possibly stemming from 3D magnetic reconnectio
 n at the footpoints\, which is consistent with other findings in this work
 .\nSpeaker: Eva Salo Viladesau
LAST-MODIFIED:20260110T163357Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Understanding the Physics of Small-Scale Hot Coronal 
 Loops (Eva Sola Viladesau)
URL;VALUE=URI:https://www.mps.mpg.de/events/44331/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/44332/7840847
DTSTART:20260129T100000Z
DTEND:20260129T110000Z
CLASS:PUBLIC
CREATED:20260110T163937Z
DESCRIPTION:We discuss how to optimise the science output of the European S
 olar Telescope (EST)\, when used without the wide-field compensation for h
 igh-altitude seeing that the EST multi conjugate adaptive optics (MCAO) wi
 ll offer. This will likely be the mode of operating EST during its first y
 ear\, following first light. In this mode\, the spatial resolution of a mu
 ch smaller telescope could surpass that of EST. We propose to operate EST 
 in multi-aperture mode\, which will\, together with the use of short expos
 ure times and image reconstruction techniques\, dramatically improve image
  quality. In particular\, the multi-aperture mode will provide the sustain
 ed stable high image quality needed for obtaining time sequences of spectr
 opolarimetric data. The multi-aperture mode is implemented by optically se
 gmenting the 4.2 m aperture into six 1.4 m subapertures by a low-cost modi
 fication of the camera lenses of the three Fabry-Perot systems that are ex
 pected to be operational soon after first light.\nSpeaker: Göran Scharmer
LAST-MODIFIED:20260121T214617Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Optimising the Use of the European Solar Telescope be
 fore MCAO: the Multi-Aperture Option (Göran Scharmer)
URL;VALUE=URI:https://www.mps.mpg.de/events/44332/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/44717/7840847
DTSTART:20260212T100000Z
DTEND:20260212T110000Z
CLASS:PUBLIC
CREATED:20260205T194804Z
DESCRIPTION: Solar flares are the most energetic manifestations of solar ac
 tivity and can significantly affect Earth’s magnetosphere\, ionosphere\,
  and technological systems. Therefore\, anticipating these events remains 
 a fundamental challenge in heliophysics. Soft X-ray observations from the 
 GOES satellites have long been used to monitor and characterize solar flar
 es. Among the various forecasting approaches\, the Flare Anticipation Inde
 x (FAI)\, originally proposed by Hudson (2025)\, has established itself as
  a promising diagnostic tool for thermal activity preceding flares. The FA
 I is based on the detection of a Hot Onset Precursor Event (HOPE)\, charac
 terized by a gradual increase in plasma temperature\, and the emission mea
 sure before the impulsive phase of a flare. In this work\, we performed a 
 statistical validation of the FAI using a representative dataset of approx
 imately 8\,000 days between 1980 and 2025. Plasma temperatures and emissio
 n measurements were derived from GOES/XRS observations\, and FAI-based ale
 rts were generated using predefined thresholds correlated with GOES solar 
 flares within a 30-minute time interval from flare start to peak. A total 
 of 48\,344 flares of different classes were analyzed\, yielding varying de
 tection rates depending on the flare class. The parameter sets were chosen
  to minimize the number of false positives and increase the detection rate
  of large flares (M and X). The results suggest that the FAI is particular
 ly sensitive to medium and large solar flares and has potential for near r
 eal-time prediction\, while also highlighting the need to optimize the thr
 esholds to improve its predictive performance for each class.\nSpeaker: Pa
 ula González-Prieto 
LAST-MODIFIED:20260205T194929Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Can we anticipate solar flares? Statistical analysis 
 of the Flare Anticipation Index (FAI) (Paula González-Prieto)
URL;VALUE=URI:https://www.mps.mpg.de/events/44717/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/44841/7840847
DTSTART:20260226T100000Z
DTEND:20260226T110000Z
CLASS:PUBLIC
CREATED:20260218T175842Z
DESCRIPTION:Understanding how magnetic properties of solar active regions i
 nfluence coronal mass ejection (CME) dynamics is essential for constrainin
 g eruption models and improving space-weather prediction. In this work\, w
 e investigate the relationship between magnetic field diagnostics derived 
 from potential-field extrapolations and the 3D speeds of CMEs.We focus on 
 physically motivated parameters associated with eruption onset\, including
  the critical height of torus instability (hcrit)\, the strength of the ov
 erlying magnetic field strength (Bt)\, and the flare ribbon flux (Rf). Whi
 le hcrit and Bt are traditionally evaluated directly above polarity invers
 ion lines (PILs)\, \; however\, identifying PILs can involve threshold-dep
 endent and partially manual selection procedures. To reduce this dependenc
 y\, we test whether these diagnostics retain predictive power when compute
 d over broader regions of interest (ROIs) within the active region\, witho
 ut relying on explicit PIL selection.Using decay index profiles derived fr
 om photospheric magnetograms\, we find a strong correlation between hcrit 
 and CME speed (r ≈ 0.71). When evaluated over progressively larger ROIs 
 centered on the PIL\, weighted hcrit from the largest region considered pr
 ovides the strongest correlation (r ≈ 0.73)\, indicating that the broade
 r active-region field structure is as informative as measurements strictly
  above the PIL. In contrast\, Bt shows weaker (r = 0.33) predictive capabi
 lity\, and combining it with hcrit offers only marginal improvement. Ribbo
 n flux exhibits moderate correlation (r = 0.44) with CME speed\, but the h
 ighest predictive power is consistently obtained when hcrit is included.Th
 ese results suggest that\, within potential-field models\, the critical he
 ight of torus instability is the dominant magnetic diagnostic of CME speed
 \, and that the large-scale magnetic environment of active regions plays a
  key role in regulating eruption dynamics.\nSpeaker: Harshita Gandhi
LAST-MODIFIED:20260218T180912Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Linking Magnetic Field Diagnostics with 3D Coronal Ma
 ss Ejection Speeds in Solar Active Regions (Harshita Gandhi)
URL;VALUE=URI:https://www.mps.mpg.de/events/44841/7840847
END:VEVENT
BEGIN:VEVENT
DTSTAMP:20260313T112406Z
UID:https://www.mps.mpg.de/events/45012/7840847
DTSTART:20260312T100000Z
DTEND:20260312T110000Z
CLASS:PUBLIC
CREATED:20260308T133849Z
DESCRIPTION:This work takes advantage of new observational data collected b
 y the High-resolution Coronal Imager (Hi-C) at the highest spatial and tem
 poral resolutions available. This most recent Hi-C dataset is the first to
  make use of the hot 129 Å channel and the first to consist of targeted o
 bservations of a solar flare\, rather than the quiescent corona. Images fr
 om Hi-C are analysed and compared with complementary EUV observations from
  SDO/AIA. The widths of the loop strands are measured\, and the resulting 
 populations analysed. Preliminary results suggest the majority of loop str
 ands have a width in the range 500-2\,000 km\, but there is some variation
  in the loop strand widths observed in plasma at different temperatures. T
 here is some evidence that there are smaller structures present which are 
 partially resolved by Hi-C\, with the very smallest smallest loop strands 
 of a similar order of magnitude to the spatial resolution of the Hi-C imag
 es. Further results will be presented\, as well as a discussion of future 
 work\, investigating individual events within the Hi-C observations\, maki
 ng use of the high cadence available to track the dynamic behaviour of the
  corona.\nSpeaker: Anna Rankin
LAST-MODIFIED:20260308T134021Z
LOCATION:https://uio.zoom.us/j/63138938090
ORGANIZER;CN=Valeriia Liakh:mailto:
SUMMARY:ESPOS: ESPOS: Exploring small-scale coronal loop structures using u
 ltra high resolution observations from the latest Hi-C sounding rocket cam
 paign (Anna Rankin)
URL;VALUE=URI:https://www.mps.mpg.de/events/45012/7840847
END:VEVENT
END:VCALENDAR