BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Poster popups DTSTART;VALUE=DATE-TIME:20230511T131500Z DTEND;VALUE=DATE-TIME:20230511T133000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-412@meetings.aip.de DESCRIPTION:Speakers: Andrei Gorobets (Leibniz-KIS)\, Carsten Denker (Leib niz Institute for Astrophysics Potsdam (AIP))\, Francesco Berrilli (Univer sity of Rome Tor Vergata)\, Malcolm Druett (KU Leuven)\, Meetu Verma (Leib niz-Institut für Astrophysik Potsdam (AIP))\, Saida Milena Diaz Castillo (Leibniz Institute for Solar Physics - KIS)\, Sanghita Chandra (Max Planck Institute for Solar System Research)\nFrancesco Berrilli - The Multiscale Magnetic Signature of the Solar Turbulent Magneto-Convection\nAndrei Goro bets - Co-existence of self-similarity and anomalous scaling in photospher ic turbulent small-scale magnetic fields\nMalcolm Druett - Comparing the e volution of mottles and fibrils in a radiation-MHD simulation\nCarsten Den ker - Instruments for High-resolution Solar Observations\nSaida Milena Dia z Castillo - Signatures of an impulsive jet in a small-scale magnetic torn ado: Spectro-polarimetric observations of a dynamic photospheric small-sca le magnetic vortex associated with a chromospheric swirl\n\nhttps://meetin gs.aip.de/event/24/contributions/412/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/412/ END:VEVENT BEGIN:VEVENT SUMMARY:Poster popups DTSTART;VALUE=DATE-TIME:20230510T142000Z DTEND;VALUE=DATE-TIME:20230510T143500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-411@meetings.aip.de DESCRIPTION:Speakers: Salvo Guglielmino (Istituto Nazionale di Astrofisica (INAF))\, Sibaek Yi (Kyung Hee University)\, Sofya Belov (Branišovská 1 760\, 37005 České Budějovice)\, Tino L. Riethmüller (Max-Planck-Instit ut für Sonnensystemforschung\, Justus-von-Liebig-Weg 3\, 37077 Göttingen \, Germany)\, Xiang Li ()\, Xudong Sun (University of Hawaii)\nXudong Sun- Formation and Destruction of Kilogauss Bald Patches in a Delta-Spot Light Bridge\nSibaek Yi- A New Method of Coronal Force-Free Field Reconstructio n and Its Application to an Active Region \nSalvo Guglielmino - Multi-ins trument analysis of an eruptive M1.2 flare observed by Metis and STIX onbo ard Solar Orbiter\nTino L. Riethmüller - The potential of many-line inver sions and an outlook to its application to data recorded with state-of-the -art instrumentation\nSanghita Chandra - Investigating Chromospheric Fine Structures using MURaM\nSofya Belov - Numerical simulations of oscillatio ns in solar corona excited by vortex shedding\nXiang Li - Nature of small- scale Ca II H brightenings associated with low magnetic flux in quiet Sun region\n\nhttps://meetings.aip.de/event/24/contributions/411/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/411/ END:VEVENT BEGIN:VEVENT SUMMARY:poster popups DTSTART;VALUE=DATE-TIME:20230509T132500Z DTEND;VALUE=DATE-TIME:20230509T134500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-414@meetings.aip.de DESCRIPTION:Speakers: Arooj Faryad ()\, Fallon Konow (Georgia State Univer sity / University of Rome Sapienza / University of Rome Tor Vergata / Nat ional Institute of Astrophysics (INAF))\, José Roberto Canivete Cuissa (I RSOL)\, Matteo Cantoresi (University of Rome Tor Vergata)\, Meetu Verma ( Leibniz-Institut für Astrophysik Potsdam (AIP))\, Nikolina Milanović (Ma x Planck Institute for Solar System Research)\, Philip Lindner (Leibniz-In stitut fuer Sonnenphysik (KIS))\nFallon Konow - A New Instrument for Synop tic Space Weather Observations \nMeetu Verma- Tales of Two Pores – Obser ved with GREGOR IFU and HiFI\nJosé Roberto Canivete Cuissa - Vortices and Alfvénic pulses in the simulated solar atmosphere \nArooj Faryad - Aut omatic detection of Ellerman bombs in Halpha using COCOPLOTs \nNikolina Mi lanović - Thermal structuring and evolution of coronal bright points \nMa tteo Cantoresi - Scaling properties of Coronal Holes photospheric magneti c fields\nPhilip Lindner - Decay of a photospheric transient filament at t he boundary of a pore and the chromospheric response\n\nhttps://meetings.a ip.de/event/24/contributions/414/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/414/ END:VEVENT BEGIN:VEVENT SUMMARY:Do ions and neutral atoms behave differently in solar prominences? DTSTART;VALUE=DATE-TIME:20230510T104000Z DTEND;VALUE=DATE-TIME:20230510T105500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-331@meetings.aip.de DESCRIPTION:Speakers: Horst Balthasar (Leibniz-Institute for Astrophysics Potsdam)\nSolar prominences consist of a thin thus low-collisional and par tially ionized plasma.\n Therefore\, the coupling of ions and neutra l atoms is much weaker than in photosphere\, \n and ions are affecte d by the Lorentz-force\, while neutral atoms are not.\n To investiga te this issue\, we performed simultaneous observations of the spectral lin es \n of several ions and neutral atoms with THEMIS at the Observato rio del Teide\, Tenerife.\n The selected spectral lines are opticall y thin\, so that we probe also the inner part \n of the prominence. We find that lines of ions are broadened compared to such from \n n eutral atoms\, and Sr II 4216 is even broader than Fe II lines. Lines from neutral \n metals (Mg I b2\, Na I D1) appear broader than He I 5016 \, a line from the singlet \n system. Doppler velocities also differ among the observed lines and show a typical \n sequence. Probably t he situation is more complicated than just having one ionized \n and one neutral plasma component.\n\nhttps://meetings.aip.de/event/24/contrib utions/331/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/331/ END:VEVENT BEGIN:VEVENT SUMMARY:Flare-accelerated electrons and the evolution of the associated ac tive region DTSTART;VALUE=DATE-TIME:20230510T102500Z DTEND;VALUE=DATE-TIME:20230510T104000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-333@meetings.aip.de DESCRIPTION:Speakers: Malte Bröse (AIP)\nA multi-wavelength analysis is c onducted to study flare signatures both in the\nlow and higher corona. LOF AR\, STIX/Rhessi\, and AIA data provide an extensive\npicture about differ ent aspects of flare characteristics. The active region and\nits thermal e volution are studied through Differential Emission Measure (DEM)\nreconstr uctions from AIA data. Flare-accelerated electrons and their radio\ntraces are observed with STIX and LOFAR\, respectively. These are in principal\n all associated with the energy release during the flare process. We focus on\nfluctuations of the radio sources and the thermal evolution of the ac tive\nregion\, and their possible relations. Solar magnetic fields are a b inding\nelement between low and high corona\, accelerated electrons\, and heated flare\nloops. They are included in the analysis via a Potential Fie ld Source Surface\n(PFSS) model.\n\nhttps://meetings.aip.de/event/24/contr ibutions/333/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/333/ END:VEVENT BEGIN:VEVENT SUMMARY:Modelling solar eruptive events from their onset to their propagat ion at 1 AU DTSTART;VALUE=DATE-TIME:20230510T101000Z DTEND;VALUE=DATE-TIME:20230510T102500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-330@meetings.aip.de DESCRIPTION:Speakers: Antoine Strugarek ()\nIn the era of Solar Orbiter an d Parker Solar Probe\, we have now an unprecedented view on eruptive event s of the Sun\, from their onset to their propagation in the heliosphere. T hanks to the proximity of the probes to the Sun for at least part of their orbit\, we are currently acquiring more and more key data on the structur ing and the propagation of solar eruptive events\, as well as on the accel eration of particles at each stage of the eruption and propagation.\n\nI w ill report on an on-going modelling effort of solar eruptive events using the versatile PLUTO code within the STORMGENESIS project. I will present a full MHD effort to model idealised and realistic and eruptive active regi ons\, based on the initiation of the magnetic with both non-linear force-f ree and non force-free extrapolations. I will present very recent result o n the modelling of the eruption of active region #12241\, which is well re produced when using a non force-free initiation. Coupled to charged test-p articles under the gyrokinetic approximation\, and to the heating and cool ing associated with magnetic reconnection and radiative losses\, I will pr esent first results on the prediction for thermal and non-thermal emission from this active region. \n\nIn a second part\, I will show how the same simulation framework\, now using adaptive mesh refinement\, can be used to model the propagation of coronal mass ejections from their onset to their propagation up to 1 AU in a realistically structured solar wind. These re sults\, published recently in Regnault et al. (2023)\, allow to highlight the generic features of CMES and the simulation results compare very well with superposed-epochs analysis of hundreds of CMEs. In addition\, these s imulations point towards various rotation patterns of the CMEs that depend on their size and that happen during the initial stage of their propagati on within the Alfvén surface. These results warrant further analyses\, co upling the two set of simulations presented here to provide a complete pic ture of the energetics and of thermal and non-thermal emission of solar er uptive events.\n\nhttps://meetings.aip.de/event/24/contributions/330/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/330/ END:VEVENT BEGIN:VEVENT SUMMARY:First GREGOR and IRIS simultaneous observations of a solar flare DTSTART;VALUE=DATE-TIME:20230510T095500Z DTEND;VALUE=DATE-TIME:20230510T101000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-324@meetings.aip.de DESCRIPTION:Speakers: Marta Garcia-Rivas ((1)Astronomical Institute of the CAS (2)Astronomical Institute\, Faculty of Mathematics and Physics\, Char les University)\nDuring the 8th call of the SOLARNET Trans-National Access Programme we were funded for a flare observing campaign at GREGOR (Teneri fe). This campaign was supported by additional instruments\, such as the I RIS and Hinode satellites\, and ground-based instruments at the Astronomic al Institute of the Czech Academy of Sciences in Ondřejov (CZ)\, and at t he Białków Observatory of the University of Wroclaw (PL).  \n\nOur goa l was to observe solar flares during their initial evolutionary stages and at different atmospheric layers in order to understand their structure an d the triggering processes. \n\nOn May the 4th a M5.7 flare was captured by the GREGOR Infrared Spectrograph (GRIS) and by the improved High-resolu tion Fast Imager (HiFI+) multi-wavelength imaging filtergraph. In this wor k we focus on the analysis of the temporal evolution of HiFI+ images and I RIS dataset\, with a special emphasis on the study of the continuum enhanc ement. After a proper co-alignment with respect to the IRIS dataset\, we a re able to present a multi-wavelength evolution of the flaring solar atmos phere at selected positions of interest.\n\nhttps://meetings.aip.de/event/ 24/contributions/324/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/324/ END:VEVENT BEGIN:VEVENT SUMMARY:First results on solar flares and eruptive events from the X-ray t elescope STIX on Solar Orbiter DTSTART;VALUE=DATE-TIME:20230510T094000Z DTEND;VALUE=DATE-TIME:20230510T095500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-322@meetings.aip.de DESCRIPTION:Speakers: Alexander Warmuth (Leibniz Institute for Astrophysic s Potsdam (AIP))\nOf the six remote-sensing instruments aboard Solar Orbit er\, the Spectrometer/\nTelescope for Imaging X-rays (STIX) is the one ded icated\nto the study of solar flares. It performs imaging spectroscopy\nin the hard X-ray regime\, which provides key physical diagnostics on\nboth the hot thermal plasma as well as on the accelerated energetic\nelectrons. During its operation since launch in 2020\, which now includes\nthe first year of the nominal mission phase\, STIX has detected\nover 25\,000 solar flares. The first scientific results based on these novel\nobservations w ill be discussed. In particular\, we will focus on studies\nthat use STIX jointly with other observational assets\, such as the\nother remote-sensin g instruments on Solar Orbiter\, various X-ray instruments\non other space craft\, and in-situ particle detectors.\n\nhttps://meetings.aip.de/event/2 4/contributions/322/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/322/ END:VEVENT BEGIN:VEVENT SUMMARY:Formation and early evolution of coronal mass ejections DTSTART;VALUE=DATE-TIME:20230510T091000Z DTEND;VALUE=DATE-TIME:20230510T094000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-363@meetings.aip.de DESCRIPTION:Speakers: Emilia Kilpua (University of Helsinki)\nCoronal Mass Ejections (CMEs) are in the center of interest for solar - terrestrial re search. They are interesting both from the fundamental plasma physical and space weather perspectives. The integral part of CMEs are huge magnetic flux ropes where magnetic field lines wind about a common axis. They form when magnetic energy first accumulates in the solar corona and then lose i ts balance. After being released from the Sun\, CMEs expand and propagate outwards into outer corona and interplanetary space. Their initial flux ro pe structure can change dramatically due to interactions with the ambient solar wind and with other eruptions. This presentation will review the key mechanism of how CMEs are believed to form and erupt from the Sun\, and p hysical processes behind their early evolution. Understanding their nascen t phase and evolution are paramount for reliable space weather forecasting . The status and challenges related to coronal modelling of CMEs are also discussed.\n\nhttps://meetings.aip.de/event/24/contributions/363/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/363/ END:VEVENT BEGIN:VEVENT SUMMARY:Magnetic field changes in the photosphere during solar flares and their association with flare ribbons DTSTART;VALUE=DATE-TIME:20230509T155500Z DTEND;VALUE=DATE-TIME:20230509T161000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-315@meetings.aip.de DESCRIPTION:Speakers: Rahul Yadav (University of Colorado\, Boulder)\nAbru pt and permanent photospheric magnetic field changes have been observed in many flares. It is believed that such changes are related to the reconfig uration of magnetic field lines\, however\, the real origin is still uncle ar. I will present the analysis of 37 flares observed by the Solar Dynamic s Observatory (SDO). The characteristics of the magnetic field changes in the flare events are determined using HMI high-cadence vector magnetogram (135 s)\, whereas the ribbon properties are derived from co-aligned AIA 16 00 Å images. We find that pixels swept up by ribbons do not always exhibi t permanent changes in the field. However\, when they do\, ribbon emission typically occurs several minutes before the start of field changes. The c hanges in the properties of the field show no relation to the size of acti ve regions but are strongly related to the flare-ribbon properties. We fin d that the duration of permanent changes in the field is strongly coupled with the duration of the flare. Our results suggest that changes in photos pheric magnetic fields are caused by a combination of two scenarios: contr action of flare loops driven by magnetic reconnection and coronal implosio n.\n\nhttps://meetings.aip.de/event/24/contributions/315/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/315/ END:VEVENT BEGIN:VEVENT SUMMARY:On diversity of spectral shapes of hydrogen Lyman lines and Mg II lines in a quiescent prominences DTSTART;VALUE=DATE-TIME:20230509T154000Z DTEND;VALUE=DATE-TIME:20230509T155500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-306@meetings.aip.de DESCRIPTION:Speakers: Pavol Schwartz (Astronomical Institute\, Slovak Acad emy of Sciences)\nA quiescent prominence was observed on October 22\, 2013 quasi-simultaneously and nearly co-spatially in the Lyman series of hydro gen by SoHO/SUMER and in the Mg II h&k lines by IRIS. Such spectroscopic o bservations comprising multiple lines offer an excellent opportunity for d iagnostics of prominence plasma and the dynamics of its fine structures. H owever\, it also invokes significant challenges when compared with synthet ic spectra provided by radiative transfer modelling. Only a few similar co ordinated datasets of Lyman and Mg II h&k observations were ever obtained in prominences. We present here the first spectroscopic analysis of this u nique dataset. Moreover\, for the first time\, we assess the influence of noise on the statistics of profile characteristics. We focus on the follow ing characteristics – the number of distinct peaks\, integrated line int ensity\, center-to-peak ratio describing the depth of the reversal of two- peaked profiles\, and the asymmetry of peaks. There occur many profiles of both Lyman and Mg II lines which except of two major peaks\, contain also lower peaks – hereafter called as minor peaks. Nature of these\, possib ly spurious minor peaks is uncertain. They may be either due to noise or v igorous dynamics of the prominence. We show that noise has a negligible ef fect on the integrated intensities of all lines but it significantly affec ts the classification of spectral profiles using the number of distinct pe aks\, the reversal depth and also the peak asymmetry. We also demonstrate that by taking into account an influence of noise\, we can assess which ch aracteristics of particular lines are suitable for diagnostics of differen t properties of prominence. For example\, we show that the minor peaks of the Lyman line profiles are mostly caused by noise\, which means that only the dominant peaks should be used for statistical analyses or comparisons with synthetic spectra. On the other hand\, for Mg II k&h\, distinction b etween multi-peaked profiles with low peaks and profiles with deep reversa ls lies mainly in the dynamics of multiple fine structures located along a line of sight. The complex\, multi-peaked profiles are observed in places where multiple fine structures with different line-of-sight velocities ar e crossing the line of sight while the profiles with deep reversals likely correspond to instances when we observe single fine structure or multiple fine structures but with similar line-of-sight velocities. Such results l ead to a conclusion that if we are interested in the diagnostics of dynami cs of prominence fine structures\, the best approach is to use a combinati on of profile asymmetry in the Lyman lines together with the complex profi les of Mg II h&k lines. On the other hand\, if we want to diagnose the tem perature and pressure of individual prominence fine structures\, we need t o focus on deeply reversed Mg II h&k line profiles in combination with the Lyman lines and to analyse the depth of central reversal and the integrat ed intensity.\n\nhttps://meetings.aip.de/event/24/contributions/306/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/306/ END:VEVENT BEGIN:VEVENT SUMMARY:Plasma thermalisation from wave damping seen in super-penumbral fi brils DTSTART;VALUE=DATE-TIME:20230509T152500Z DTEND;VALUE=DATE-TIME:20230509T154000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-310@meetings.aip.de DESCRIPTION:Speakers: William Bate (Queen's University Belfast)\nThe Inter ferometric Bidimensional Spectrometer (IBIS) at the Dunn Solar Telescope ( DST) was employed to capture high spatial resolution spectral scans of a s unspot in the H-alpha line. These scans allowed for the examination of sup er-penumbral fibrils\, including their transverse motions both parallel an d perpendicular to the line of sight. Near ubiquitous transverse oscillati ons of the fibrils have been observed and statistics gathered on their pro perties\, which are consistent with previous investigations. Further exami nation of cases demonstrating well-resolved fibril oscillations were perfo rmed\, which allowed us to track their propagation velocities and associat ed energy flux along the length of the fibril. Additionally\, analysis of the H-alpha line width has been performed\, which is known to correlate wi th plasma temperature. This allowed for a unique investigation of whether the energy damped from the transverse fibril oscillations provides evidenc e of thermalisation of the local plasma. Here\, I will report on the energ y damping and associated fluctuations in the H-alpha line width\, which we believe is evidence of MHD wave dissipation in the form of plasma thermal isation.\n\nhttps://meetings.aip.de/event/24/contributions/310/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/310/ END:VEVENT BEGIN:VEVENT SUMMARY:Evidence of external reconnection between an erupting mini-filamen t and ambient loops observed by Solar Orbiter/EUI DTSTART;VALUE=DATE-TIME:20230509T151000Z DTEND;VALUE=DATE-TIME:20230509T152500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-320@meetings.aip.de DESCRIPTION:Speakers: Zhuofei Li (MPS)\nMini-filament eruptions are one of the most common small-scale transients in the solar atmosphere. They are small-scale analogs to solar filaments. They are associated with coronal j ets that represent transient\, collimated plasma ejections along open fiel ds or far-reaching coronal loops. One particular type is blowout jets. The se often come along with erupting loops or twisted filaments at the base o f the jets. Consequently they have a more dynamic base and also often a wi der spire than standart jets. Recently\, a mini-filament eruption model ha s been put forward\, in which a successful mini-filament eruption drives a blowout jet\, while a partial or failed mini-filament eruption causes a s tandard jet. During blowout jets\, many blobs have been observed and drawn much attention as they could provide evidence of the magnetic reconnectio n process\, because these blobs are odten identified with plasmaoids in th e current sheet. However\, it is still difficult to observationally clarif y the relation between the moving plasma blobs and magnetic reconnection. The clarification is mainly limited by the low spatio-temporal resolution of previous data. Here\, with a combination of 174 Å images at high spati al resolution and high cadence taken by the Extreme Ultraviolet Imager on board Solar Orbiter and images of the Atmospheric Imaging Assembly on boar d Solar Dynamics Observatory\, we investigate in detail an erupting mini-f ilament over a weak magnetic field region on 2022 March 4. During the erup tion\, two bright ribbons clearly appeared underneath the erupting mini-fi lament as it quickly ascended. Subsequently\, some dark materials blew out when the erupting mini-filament interacted with the outer ambient loops\, thus forming a blowout jet characterized by a widening spire. At the same time\, a chain of small bright blobs with diameters of 1–2 Mm are inter mittently expelled from the interaction region between the erupting mini-f ilament and ambient loops and propagated along the post-eruption loops tow ard the footpoints of the erupting fluxes at a speed of ~ 100 km/s. They h ave short lifetimes\, varying from 30 s to 90 s. They also caused a semi-c ircular brightening structure. We suggest that these fast-moving blobs are evidence for magnetic reconnection. We performed a differential emission measure (DEM) analysis and found that various brightenings show plasma tha t is heated during the mini-filament eruption\, e.g. two bright ribbons\, footpoints of the ambient loops\, and the interaction region. Based on the features aforementioned\, we suggest that the mini-filament eruption firs t experiences internal reconnection that occurs underneath the erupting mi ni-filament and then external reconnection between the mini-filament and t he ambient loops. The transfer of mass and magnetic flux from the erupting mini-filament to the ambient corona is mainly due to the external reconne ction.\n\nhttps://meetings.aip.de/event/24/contributions/320/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/320/ END:VEVENT BEGIN:VEVENT SUMMARY:On the stability of large magnetic solar structures DTSTART;VALUE=DATE-TIME:20230509T145500Z DTEND;VALUE=DATE-TIME:20230509T151000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-321@meetings.aip.de DESCRIPTION:Speakers: Jan Jurcak (Astronomical Institute of the CAS)\nWe w ill review the recent observational results that show the key role played by the vertical component of the magnetic field (B$_\\mathrm{ver}$) in the inhibition of convection in the solar photosphere. In sunspots\, only reg ions with B$_\\mathrm{ver}$ stronger than a critical value of approximatel y 1.8 kG (the critical value is dependent on the data used\, definition of the umbral boundary\, inversion scheme\, etc.) are stable against convect ion and the intensity boundaries of stable umbrae can be equally outlined by this critical B$_\\mathrm{ver}$. In regions with B$_\\mathrm{ver}$ weak er than the critical value\, more vigorous modes of magneto-convection tak e over. This behavior is observed during the formation of penumbra and lig ht bridges and during the decay of sunspots and pores. We will compare the se observations to analyses of sunspots simulations and to theoretical mod els describing the stability of overturning convection in the presence of magnetic fields and we will discuss the repercussion in the life cycle of magnetic structures.\n\nhttps://meetings.aip.de/event/24/contributions/321 / LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/321/ END:VEVENT BEGIN:VEVENT SUMMARY:Sunspot penumbral evolution: a puzzle under construction DTSTART;VALUE=DATE-TIME:20230509T143000Z DTEND;VALUE=DATE-TIME:20230509T145500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-358@meetings.aip.de DESCRIPTION:Speakers: Mariarita Murabito (INAF OACN)\nThe penumbra is an i ntriguing part of a sunspot where the coupling between magnetic field and plasma is characterized by peculiar physical conditions. Although it has b een the focus of many observational and theoretical studies\, the processe s involved in the formation and decay of a sunspot penumbra are still not fully understood. I will give a brief summary of recent observations leadi ng valuable contributions to better understanding these processes.\n\nhttp s://meetings.aip.de/event/24/contributions/358/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/358/ END:VEVENT BEGIN:VEVENT SUMMARY:Insights Into Confined/Eruptive Stellar Flare Nature using Compreh ensive Statistical Analysis of Magnetic and Thermodynamic Properties of So lar Flares Observations DTSTART;VALUE=DATE-TIME:20230509T103000Z DTEND;VALUE=DATE-TIME:20230509T104500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-308@meetings.aip.de DESCRIPTION:Speakers: Maria Kazachenko (University of Colorado - Boulder / National Solar Observatory)\nSolar flares sometimes lead to coronal mass ejections that directly affect the Earth's environment. However\, a large fraction of flares\, especially on solar-type stars\, are confined flares. What are the differences in physical properties between confined and erup tive flares? For the first time\, we quantify thermodynamic and magnetic properties of hundreds confined and eruptive flares of GOES class C5.0 and above\, 480 flares total. We first analyze large flares of GOES class M1. 0 and above observed by the SDO\, 216 flares total\, including 103 eruptiv e and 113 confined flares\, from 2010 until 2016 April\; we then look at t he entire dataset above C5.0 of 480 flares. We compare GOES X-ray thermody namic flare properties\, including peak temperature and emission measure\, and active-region and flare-ribbon magnetic field properties\, including reconnected magnetic fluxes and peak reconnection rates. We find that conf ined and eruptive flares have similar distributions of reconnection flux. Confined flares\, however\, have larger peak magnetic reconnection rates\, are more compact\, and occur in larger active regions than eruptive flare s. These findings suggest that confined flares are caused by reconnection within more compact\, stronger\, lower lying magnetic-field regions in lar ger ARs that reorganizes smaller fractions of ARs. This reconnection proce eds at faster rates and ends earlier\, leading potentially to more efficie nt flare particle acceleration in confined flares.\n\nhttps://meetings.aip .de/event/24/contributions/308/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/308/ END:VEVENT BEGIN:VEVENT SUMMARY:Detection of the Evershed flow by the application of the SOM techn ique DTSTART;VALUE=DATE-TIME:20230509T101500Z DTEND;VALUE=DATE-TIME:20230509T103000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-314@meetings.aip.de DESCRIPTION:Speakers: Paolo Romano (INAF - Catania Astrophysical Observato ry)\nWe present the results obtained from applying the Self Organizing Map technique to a spectral dataset of monochromatic images acquired by the I nterferometric Bidimensional Spectropolarimeter at the Dunn Solar Telescop e\, along the Ca II 854.2 nm and Hα 656.28 nm lines. This technique allow ed us to segment the photospheric and chromospheric penumbra fine structur e\, revealing the presence of the Evershed flow in the chromosphere along the portions of the penumbral filaments near the umbra. In addition\, the flow velocity as a function of distance from the spot center in the periph eral regions of the super-penumbra was consistent with the inverse-Evershe d flow. These signatures\, along with slight differences in the chromosphe ric plasma velocities measured along the two spectral lines\, provided us with the opportunity to combine the Evershed and inverse-Evershed flows in the same context\, in accordance with the uncombed model of the sunspot p enumbra.\n\nhttps://meetings.aip.de/event/24/contributions/314/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/314/ END:VEVENT BEGIN:VEVENT SUMMARY:Sausage wave modes in small magnetic pores observed with Solar Orb iter/PHI DTSTART;VALUE=DATE-TIME:20230509T100000Z DTEND;VALUE=DATE-TIME:20230509T101500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-305@meetings.aip.de DESCRIPTION:Speakers: Shahin Jafarzadeh (Max Planck Institute for Solar Sy stem Research\, Germany))\nWe have exploited seeing-free and high-quality observations of several small magnetic pores from the High Resolution Tele scope (HRT) of the Polarimetric and Helioseismic Imager (PHI) on board the Solar Orbiter spacecraft\, during its first close perihelion in March 202 2 (at a distance of 0.5 au from the Sun). Only such small magnetic pores\, captured at stable observing conditions\, could manifest (large) area flu ctuations\, on the order of 30% variations\, that is an indication of (non -linear) fast sausage (surface) modes. Furthermore\, cross correlations be tween perturbations in intensity\, area\, line-of-sight velocity\, and mag netic fields have provided us with additional wave signatures\, that toget her with applications of modern analysis techniques\, such as the Spectral Proper Orthogonal Decomposition (SPOD)\, we have been able to characteris e the underlying MHD wave modes in more details.\n\nhttps://meetings.aip.d e/event/24/contributions/305/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/305/ END:VEVENT BEGIN:VEVENT SUMMARY:Scrutinising nature of magnetic and flow fields in complex active region with HiFI+ and GRIS DTSTART;VALUE=DATE-TIME:20230509T094500Z DTEND;VALUE=DATE-TIME:20230509T100000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-297@meetings.aip.de DESCRIPTION:Speakers: Robert Kamlah (Leibniz-Institut fuer Astrophysik Pot sdam (AIP))\nThis study investigates the photospheric and chromospheric fl ow field in active region NOAA 13096\, which consists of pores\, sunspots with partial penumbrae\, and light bridges. The improved High-resolution F ast Imager (HiFI+) and GREGOR Infrared Spectrograph (GRIS) acquired high-r esolution data at the 1.5-meter GREGOR solar telescope at Observatorio del Teide\, Izaña\, Tenerife\, Spain. The Helioseismic and Magnetic Imager ( HMI) onboard the Solar Dynamics Observatory (SDO) complements the GREGOR d ata with synoptic full-disk continuum images and line-of-sight (LOS) magne tograms. Background-Subtracted Activity Maps (BaSAMs) were used to locate areas with enhanced activity\, for which Local Correlation Tracking (LCT) provides horizontal proper motions and GRIS LOS velocities and full-Stokes polarimetry. We present first results of the three-dimensional photospher ic and chromospheric flow and magnetic fields scrutinizing the (inverse) E vershed effect in a complex active region.\n\nhttps://meetings.aip.de/even t/24/contributions/297/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/297/ END:VEVENT BEGIN:VEVENT SUMMARY:Active region evolution DTSTART;VALUE=DATE-TIME:20230509T091500Z DTEND;VALUE=DATE-TIME:20230509T094500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-408@meetings.aip.de DESCRIPTION:Speakers: Lucie Green (MSSL)\nhttps://meetings.aip.de/event/24 /contributions/408/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/408/ END:VEVENT BEGIN:VEVENT SUMMARY:Time-normalized plasma flow mapping during the quadrature of SolO and SDO DTSTART;VALUE=DATE-TIME:20230512T101500Z DTEND;VALUE=DATE-TIME:20230512T103000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-352@meetings.aip.de DESCRIPTION:Speakers: Gabriel Muro (Aberystwyth University)\nObservations of plasma motions in the low corona are often limited to magnetic field li nes originating in active regions\, which are ideal for spatial domain enh ancements across individual extreme ultraviolet (EUV) images to see loops\ , flares\, and other bright activity contrasted against dim background fea tures.\n\nThe quiet Sun is essentially all dim background features\, which requires advanced image processing and ideal observation parameters to em phasize the temporal domain in order to visualize faint\, fine-scale plasm a flows. We utilize time-normalized optical flow (TNOF) on large sets of h igh cadence EUV data by reducing instrumental noise to a high degree and t hen emphasizing the minor brightness variations indicative of plasma motio n. Maps of plasma flow paths are produced via optical flow tracking algori thms by the computer vision method of Lucas-Kanade and the underlying velo city field is estimated with line integral convolution.\n\nTo test the eff ectiveness of the TNOF approach\, we have applied this method to an EUV ca se study of data from EUI 174 and AIA 171 on 29 March 2022. This date mark ed a near-perpendicular line of sight orientation between the two spacecra ft\, had similarly short observation intervals\, and provided the opportun ity to compare contrast enhanced plasma features off-limb with temporally enhanced on-disk plasma motion. \n\nIn this case study\, we generated movi es and flow paths that show TNOF succeeds at qualitatively outlining plasm a flow along magnetic field lines from both Solar Orbiter’s and SDO’s point of view which are in general agreement with potential field models. Additionally\, detailed velocities of plasma motion within coronal loops\, overall velocity trends\, and a new quasi-magnetic flow trend within the quiet Sun are presented.\n\nhttps://meetings.aip.de/event/24/contributions /352/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/352/ END:VEVENT BEGIN:VEVENT SUMMARY:Generative deep learning with high-resolution SDO EUV images of th e Sun DTSTART;VALUE=DATE-TIME:20230512T100000Z DTEND;VALUE=DATE-TIME:20230512T101500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-351@meetings.aip.de DESCRIPTION:Speakers: Frederic Effenberger (Ruhr-University Bochum)\nWe pr esent results of generative deep learning as applied to a large database o f solar images and discuss challenges in training and validation\, in part icular with distributed training on GPU supercomputers. Our dataset is bas ed on SDO EUV data with high resolution and with excellent coverage since 2010. This dataset is thus well suited to study the application of advance d machine learning techniques that require large amounts of data for train ing\, such as deep learning approaches. We focus on diffusion type models and generative adversarial deep learning (GANs). We address the potential of data augmentation techniques for improved learning and image quality an d the opportunities for latent space structure exploration and control. Th e challenges in reaching the highest resolutions with good image fidelity are analyzed. Potential application downstream that can make use of such g enerated images are briefly discussed and the need for a community-driven\ , physics-based basis to establish evaluation criteria for generative mode ls will be emphasized.\n\nhttps://meetings.aip.de/event/24/contributions/3 51/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/351/ END:VEVENT BEGIN:VEVENT SUMMARY:Physics-informed neural networks for solar magnetic field simulati ons DTSTART;VALUE=DATE-TIME:20230512T094500Z DTEND;VALUE=DATE-TIME:20230512T100000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-350@meetings.aip.de DESCRIPTION:Speakers: Robert Jarolim ()\nPhysics-informed neural networks (PINNs) provide a novel approach for numerical simulations\, tackling chal lenges of discretization and enabling seamless integration of noisy data a nd physical models (e.g.\, partial differential equations). In this presen tation\, we highlight the new opportunities for solar magnetic field model ling that are enabled through physics-informed machine learning.\nWe prese nt a novel approach for coronal magnetic field extrapolation using physics informed neural networks. The neural network is optimized to match observ ations of the photospheric magnetic field vector at the bottom-boundary\, while simultaneously satisfying the force-free and divergence-free equatio ns in the entire simulation volume. We demonstrate that our method can acc ount for noisy data and deviates from the physical model where the force-f ree magnetic field assumption cannot be satisfied.\nWe utilize meta-learni ng concepts to simulate the evolution of the active region 11158. Our simu lation of 5 days of observations at full cadence\, requires about 12 hours of total computation time. The derived evolution of the free magnetic ene rgy and helicity in the active region\, shows that our model captures flar e signatures\, and that the depletion of free magnetic energy spatially al igns with the observed EUV emission. With this we present the first method that can perform realistic magnetic field extrapolations in quasi real-ti me\, which enables advanced space weather monitoring. \nWe conclude with a n outlook on our ongoing work where we extend this approach to create a ne w class of MHD simulations\, that can flexibly incorporate additional obse rvational constraints and perform fast computations.\n\nhttps://meetings.a ip.de/event/24/contributions/350/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/350/ END:VEVENT BEGIN:VEVENT SUMMARY:Identification of large scale resonant modes in sunspots in the lo wer solar atmosphere DTSTART;VALUE=DATE-TIME:20230512T092000Z DTEND;VALUE=DATE-TIME:20230512T094500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-359@meetings.aip.de DESCRIPTION:Speakers: Marco Stangalini (ASI Italian Space Agency)\nA solar magnetic flux tube\, like any physical system\, is capable of supporting a variety of resonances\, which constitute its natural response to externa l forcing. Apart from a few single low order eigenmodes in small scale mag netic structures\, several simultaneous resonant modes were not found unti l recently. These eigenmodes are associated to small but coherent oscillat ions and require the application of particular spatial filtering technique s to be detected.\nIn this talk I will report and discuss about the detect ion and physical implications of large scale coherent oscillations in a su nspot\, with a spectrum significantly different from p-modes.\n\nhttps://m eetings.aip.de/event/24/contributions/359/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/359/ END:VEVENT BEGIN:VEVENT SUMMARY:poster popups DTSTART;VALUE=DATE-TIME:20230508T133000Z DTEND;VALUE=DATE-TIME:20230508T134500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-413@meetings.aip.de DESCRIPTION:Speakers: Bartosz Dabrowski (Space Radio-Diagnostics Research Centre\, University of Warmia and Mazury)\, Fabio Duvan Lora Clavijo (Univ ersidad Industrial de Santander)\, Frederic Schuller (AIP)\, Markus Roth ( Thüringer Landessternwarte)\, Merlin Mendoza (Department of Space Science and Engineering\, National Central University\, Taiwan)\, Robbe Vansintja n (Royal Observatory of Belgium)\, Ziwen Huang (Max-planck Institute for S olar System Research)\nRobbe Vansintjan - The SOLARNET project and the Sol ar Virtual Observatory (SVO)\nFabio Duvan Lora Clavijo - Effect of the Hal l term on the energy release and the magnetic reconnection rate in solar f lares\nMerlin Mendoza - Association between Magnetic Pressure Difference a nd Movement of Solar Pores\nBartosz Dabrowski - Fine structures of a solar bursts observed with LOFAR\nMarkus Roth - SolarLab as Pathfinder towards SPRING\nFrederic Schuller - Pointing stability of Solar Orbiter and its in struments\nZiwen Huang - Imaging and spectroscopic observations of EUV bri ghtenings using EUI and SPICE on board of SOLAR ORBITER\n\nhttps://meeting s.aip.de/event/24/contributions/413/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/413/ END:VEVENT BEGIN:VEVENT SUMMARY:Microlensed Hyperspectral Imagers DTSTART;VALUE=DATE-TIME:20230508T154000Z DTEND;VALUE=DATE-TIME:20230508T160500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-356@meetings.aip.de DESCRIPTION:Speakers: Michiel van Noort (MPS)\nTo infer the physical condi tions in the solar atmosphere\, it is necessary to record not only the spa tial distribution of the emerging radiation\, but also its spectral and po larimetric properties. Traditionally\, solar instrumentation has accomplis hed this by recording slices through the spatio-spectral domain\, and scan ning in the missing dimension. A Microlensed Hyperspectral Imager (MiHI) i s an instrument that is able to observe a spatio-spectral cube instantaneo usly\, thus eliminating the need to scan. This increases the photon effici ency of the observations\, and with the aid of state of the art cameras al lows for the acquisition of very high cadence data. Combined with image re storation\, high resolution spectra with a spatial resolution close to the diffraction limit of the telescope can be obtained at a cadence of less t han one second\, in all four Stokes parameters. The talk covers the basic principle of operation\, data extraction and restoration\, and some exampl es of data recorded at the Swedish Solar Telescope.\n\nhttps://meetings.ai p.de/event/24/contributions/356/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/356/ END:VEVENT BEGIN:VEVENT SUMMARY:DKIST observations of small-scale\, internetwork magnetism in the quiet Sun DTSTART;VALUE=DATE-TIME:20230508T152500Z DTEND;VALUE=DATE-TIME:20230508T154000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-299@meetings.aip.de DESCRIPTION:Speakers: ryan campbell (queen's university belfast)\nA new er a of solar physics commences with observations of the quiet Sun using the 4-metre Daniel K. Inouye Solar Telescope/Visible Spectropolarimeter (DKIST /ViSP). We present full-Stokes observations at a spatial resolution of 0.1 ’’\, taken during DKIST’s cycle 1 Operations Commissioning Phase\, i n the Fe I 630.1/630.2 nm and Ca II 854.2 nm lines\, allowing us to examin e small-scale magnetism in the photosphere and chromosphere. We focus on t he photospheric diagnostic and use the Stokes Inversion based on Response functions (SIR) code to invert the Fe I line pair. This allows us to chara cterize the thermodynamic\, kinematic and\, crucially\, magnetic propertie s of the pervasive small-scale magnetic features present in the data in th e photosphere – namely\, constraining their magnetic field strengths\, f illing factors\, and magnetic inclinations. We reveal small-scale magnetic structures\, including magnetic bi-poles/loops\, in unprecedented detail. \n\nhttps://meetings.aip.de/event/24/contributions/299/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/299/ END:VEVENT BEGIN:VEVENT SUMMARY:First light and science of the UCoMP instrument of MLSO: the magne tic and thermodynamic morphology of CME precursors and eruptions DTSTART;VALUE=DATE-TIME:20230508T151000Z DTEND;VALUE=DATE-TIME:20230508T152500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-301@meetings.aip.de DESCRIPTION:Speakers: Maurice Wilson (NCAR High Altitude Observatory)\nTh e mechanism for the storage and release of magnetic energy in coronal mass ejections (CMEs) remains a major unsolved problem of Heliophysics. Thus\, observations of the coronal magnetic field before\, during\, and after th e eruption are crucial both for scientific progress and space weather pred ictions. We use the newly built Upgraded Coronal Multichannel Polarimeter (UCoMP) instrument from the Mauna Loa Solar Observatory (MLSO) to study t he magnetic and thermodynamic morphology of CME precursors and eruptions. With this coronagraph's 20-cm aperture and field of view extending from 1 .05 to 2.0 solar radii\, we determine the magnetic field orientation of pr e- and post-CME coronal loops using Stokes Q and U parameters as derived f rom the linearly polarized radiation observed from the Fe XIII 1074 nm spe ctral line. To ascertain the density\, temperature\, and ionization distr ibution of the hot plasma\, we compare and contrast the structures seen at 1074 nm with the coronal features observed by UCoMP at the Fe X 637 nm li ne\, the Fe XV 706 nm line\, the Fe XI 789 nm line\, and the Fe XIII 1079 nm line. In this study\, we use several CME precursors and eruptions as e xamples for showcasing the unique capabilities of UCoMP\, which will infor m the future of ground-based coronograph polarimeter observations that wil l eventually be performed with the COronal Solar Magnetism Observatory (CO SMO).\n\nhttps://meetings.aip.de/event/24/contributions/301/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/301/ END:VEVENT BEGIN:VEVENT SUMMARY:SunDish Project: Single-Dish Solar Imaging and calibration in K-ba nd with the INAF Radio Telescopes DTSTART;VALUE=DATE-TIME:20230508T145500Z DTEND;VALUE=DATE-TIME:20230508T151000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-302@meetings.aip.de DESCRIPTION:Speakers: Sara Mulas (INAF-OAC)\nThe SunDish project aims to m ap and monitor the Sun at high radio frequencies with the Italian Sardinia (64-m) and Medicina (32-m) Radio Telescopes in the K-band range (18-26 GH z)\, up to 100 GHz in perspective. Since the two instruments were not orig inally designed to observe the Sun\, a new solar radio imaging system was implemented. To date we acquired more than 350 solar maps with resolutions in the 0.7-2 arcmin range\, filling the observational gap in the field of chromospheric imaging at these frequencies to date.\n\nObservations of th e brightness temperature of the solar atmosphere in the radio band can map plasma processes that produce free-free emission in the local thermodynam ic equilibrium and gyromagnetic phenomena\, providing a probe of physical conditions in a wide range of atmospheric layers both for quiet and active regions.\n\nAs a first early science result of the project\, we present t he first catalog of radio continuum solar imaging observations with Medici na 32-m and SRT 64-m radio telescopes including the multi-wavelength ident ification of active regions\, their brightness and spectral characterizati on. The interpretation of the observed emission as thermal bremsstrahlung components combined with gyro-magnetic variable emission pave the way to t he use of our system for long-term monitoring of the Sun. Single-dish radi o imaging represents an ideal technique to perform accurately calibrated s olar observations. We obtained obtained unprecedented and very precise cal ibrated measurements of the Quiet Sun in the K-band affected by a mean rel ative error of 3%.\n\nThrough systematic monitoring of the Sun\, our syste m can provide accurate measurement of the brightness temperature of the ra dio-quiet Sun component\; characterization of the flux density\, spectral properties and long-term evolution of dynamical features (active regions\, coronal holes\, loop systems\, streamers\, and the coronal plateau)\; pre diction of powerful flares through the detection of peculiar spectral vari ations in the active regions\, as a valuable forecasting probe for the Spa ce Weather hazard network.\n\nhttps://meetings.aip.de/event/24/contributio ns/302/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/302/ END:VEVENT BEGIN:VEVENT SUMMARY:FRANCIS: a fibre-fed prototype integral field unit for the near-UV DTSTART;VALUE=DATE-TIME:20230508T143000Z DTEND;VALUE=DATE-TIME:20230508T145500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-353@meetings.aip.de DESCRIPTION:Speakers: David Jess (Queen's University Belfast)\nThe Fibre-R esolved opticAl and Near-ultraviolet Czerny-Turner Imaging Spectropolarime ter (FRANCIS) was developed as a low-budget prototype integral field unit for the upcoming Indian National Large Solar Telescope. At its core\, FRAN CIS is a fibre-fed Czerny-Turner spectrograph that is designed to work wit hin the spectral range of 350-700 nm\, hence enabling high cadence and spa tially resolved studies of spectral lines in the near-ultraviolet. In the summer of 2022\, FRANCIS was shipped to the Dunn Solar Telescope in the Sa cramento Peak mountains\, New Mexico\, USA\, where it was commissioned and underwent science verification. The first-light observations are very enc ouraging\, with the final data products suitable for mainstream scientific exploitation. Here\, I will overview the history of the instrument\, prov ide a snapshot of its strengths and associated weaknesses\, indicate a tim escale for future upgrades\, as well as provide samples of its spectral im aging capabilities. At present\, FRANCIS is available as a common user ins trument at the Dunn Solar Telescope\, so I will also highlight how interes ted parties can become involved with future observing campaigns.\n\nhttps: //meetings.aip.de/event/24/contributions/353/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/353/ END:VEVENT BEGIN:VEVENT SUMMARY:Solar-cycle variation of the quiet-sun magnetism DTSTART;VALUE=DATE-TIME:20230511T102000Z DTEND;VALUE=DATE-TIME:20230511T103500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-337@meetings.aip.de DESCRIPTION:Speakers: Andreas Korpi-Lagg (Max Planck Institute for Solar S ystem Research / Aalto University)\nSolar dynamo models can explain the pr oduction and maintenence of the solar magnetic fields on two different spa tial scales: the large-scale solar dynamo\, manifested in the cycle-depend ent appearance of solar active regions\, and the small-scale solar dynamo\ , driven by the turbulent convective motions close to the solar surface. D isentangling these two mechanisms observationally is extremely challenging \, but provides important input for the dynamo models. Highly stable long- term observations with sufficient magnetic sensitivity are required.\n\nTh e Helioseismic Imager on board the Solar Dynamics Observatory (SDO/HMI) ha s measured the solar magnetic field for more than one solar cycle. In ths work\, we present the results of these 13-year long magnetic field measure ments in the most quiet patches of the solar surface after applying a comb ination of a temporal and spatial averaging algorithm and a careful select ion process. The results provide strong evidence for a solar-cycle modulat ion in even the most quiet patches when they include network fields. In co ntrast\, the modulation is absent in the internetwork fields\, where only the interior of the supergranular cells is included in the analysis.\n\nWe interpret the absence of a solar-cycle modulation in the internetork fiel ds as a consequence of them being generated by the small-scale (or fluctua ting) dynamo acting on scales smaller than a supergranular cell. The solar cycle modulation when including the network fields can be explained by ta ngling of the solar-cycle dependent large-scale sub-surface field.\n\nhttp s://meetings.aip.de/event/24/contributions/337/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/337/ END:VEVENT BEGIN:VEVENT SUMMARY:Data-driven model of temporal evolution of the solar Mg II h & k p rofiles over the solar cycle DTSTART;VALUE=DATE-TIME:20230511T100500Z DTEND;VALUE=DATE-TIME:20230511T102000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-341@meetings.aip.de DESCRIPTION:Speakers: Julius Koza (Astronomical Institute\, Slovak Academy of Sciences)\nThe solar radiation in the cores of the Mg II h & k spectra l lines strongly correlates with solar magnetic activity and global variat ions of magnetic fields with the solar cycle. This work provides a data-dr iven model of temporal evolution of the solar full-disk Mg II h & k profil es over the solar cycle. Based on selected 76 IRIS near-UV full-Sun mosaic s covering almost the full solar cycle 24\, we find the parameters of doub le-Gaussian fits of the disk-averaged Mg II h & k profiles and a model of their temporal evolution parameterized by the Bremen composite Mg II index . The Markov Chain Monte Carlo algorithm implemented in the IDL toolkit So BAT is used in modeling and predicting temporal evolution of the Mg II h & k peak-to-center intensity ratio and the Bremen Mg II index. The relevan t full-disk Mg II h & k calibrated profiles with uncertainties and spectra l irradiances are provided as an online machine-readable table. To facilit ate utilization of the model corresponding routines\, written in IDL\, are made publicly available at GitHub.\n\nhttps://meetings.aip.de/event/24/co ntributions/341/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/341/ END:VEVENT BEGIN:VEVENT SUMMARY:Role of spots in stellar Ca II H & K emissions: what can we learn from spots on the Sun? DTSTART;VALUE=DATE-TIME:20230511T095000Z DTEND;VALUE=DATE-TIME:20230511T100500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-340@meetings.aip.de DESCRIPTION:Speakers: Sowmya Krishnamurthy (Max Planck Institute for Solar System Research)\nEmission in the Ca II H & K spectral lines is sensitive to the changes in the stellar magnetic activity and is a good proxy for s tudying stellar magnetic fields. This emission is most commonly characteri zed via the S-index\, representing the flux in the Ca II H & K line cores relative to the flux in the nearby continuum. The sources of stellar Ca II emissions are yet to be investigated in detail. Empirical and physics-bas ed models have shown faculae/plage to be the main source of Ca II emission s and thus neglect the contribution from spots. This is because the solar surface coverage by spots is much smaller than those by faculae. Further\, spots are assumed to be equally dark in the Ca II line cores and the cont inuum so that they do not affect the S-index. While this is a good approxi mation for old less-active stars such as the Sun\, for young active stars with large surface coverages by spots\, the role played by spots might bec ome significant. \n\n\nHere we use high quality sunspot observations in th e Ca II H line from the Swedish Solar Telescope to determine the Ca II flu x from chromospheric counterparts of sunspots. We find that spots are brig hter than the surrounding quiet regions in the chromosphere. Using the sun spot flux computed from observations in our physics-based model which also accounts for the effect of faculae\, we compute S-index for four solar ac tivity cycles. We find that sunspots lead to an increase in the S-index. H owever\, this increase is quite small to have a significant impact on the observed solar Ca II emissions. Further\, we compute S-indices considering cases of stars which are more active than the Sun. Previous studies have indicated that surface coverages of spots increase much faster with increa sing activity than the coverages by faculae. We show that with increasing activity and hence spot area coverages\, S-index increases steeply suggest ing that Ca II emissions of active stars have a significant contribution f rom spots.\n\nhttps://meetings.aip.de/event/24/contributions/340/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/340/ END:VEVENT BEGIN:VEVENT SUMMARY:Power supply and evolution of the solar dynamo DTSTART;VALUE=DATE-TIME:20230511T093500Z DTEND;VALUE=DATE-TIME:20230511T095000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-338@meetings.aip.de DESCRIPTION:Speakers: Quentin Noraz (Rosseland Centre for Solar Physics\, University of Oslo\, P.O. Box 1029 Blindern\, Oslo\, NO-0315\, Norway)\nTh e solar magnetic field is generated and sustained by the combined action o f turbulent convection and differential rotation. This dynamo process can sometimes lead to magnetic cyclic variabilities\, like the solar 11 years cycle. Traces of magnetic cycles have also been detected in other solar-li ke stars\, ranging from a few years to a few tens of years. How is the sol ar cycle period controlled?\nRecent 3D numerical simulations of solar-like stars show that different regimes of differential rotation can be charact erized with the Rossby number (advection over Coriolis force). In particul ar\, “anti-solar” differential rotation (fast poles\, slow equator) ma y appear for high Rossby number (slow rotators). If large-scale flows tran sitions occur during the solar main sequence\, we may wonder how the magne tic generation will be impacted.\n\nWe present a numerical multi-D study t o understand the magnetic field generation and evolution of solar-like sta rs under various differential rotation regimes\, in a Sun in time context. We find that short and local cycles near the surface are favoured for sma ll Rossby numbers (fast rotators)\, while long and global cycles appear fo r intermediate (solar-like) Rossby numbers. Slow rotators (high Rossby num ber) are found to produce statistically steady dynamo with no cyclic activ ity in most cases considered. We further evaluate energy transfers in thes e models and quantify that dynamos can be powered by up to 3% of the stell ar luminosity\, part of it being then available to power surface events. I n this regard\, future Solar Orbiter observations outside the ecliptic wil l provide fantastic constraints on solar polar caps magnetic field\, and t hus on the type of dynamo that our Sun is most likely to operate.\n\nhttps ://meetings.aip.de/event/24/contributions/338/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/338/ END:VEVENT BEGIN:VEVENT SUMMARY:The relation of the Sun’s global magnetic field with the solar w ind parameters on solar cycle time-scales DTSTART;VALUE=DATE-TIME:20230511T081000Z DTEND;VALUE=DATE-TIME:20230511T082500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-339@meetings.aip.de DESCRIPTION:Speakers: Raffaele Reda (University of Rome Tor Vergata)\nVari ations of the solar magnetic field are the main sources of several manifes tations of the solar activity (e.g. flares\, CMEs\, solar wind). A way to quantify such variations is by means of a physical index\, the Ca II K ind ex\, which has been proven to be a great proxy for the line-of-sight unsig ned magnetic flux density along all phases of the cycle\, and not only whe n sunspots are present.\nIn this respect\, an assessment of the long-term behaviour of the solar wind is of paramount importance to understand the n ature of its relationship with the global magnetic field of the Sun and wi th its cycle-to-cycle variations. Here\, we study the variations of physic al proxies of the solar activity (i.e. Ca II K index\, Mg II index)\, on s olar cycle time-scales\, and how they are related to variations of solar w ind parameters. The available time series allow to evaluate this relation over the last five solar cycles (from 1965 to now).\nBy adopting a climato logical approach\, the results show that there is a delayed response of th e solar wind with respect to the solar activity\, but such response is not the same for the different solar cycles. The analysis offers the possibil ity to deepen the understanding of the processes that link the global dyna mo to solar variability and to the properties of the solar wind near the E arth.\n\nhttps://meetings.aip.de/event/24/contributions/339/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/339/ END:VEVENT BEGIN:VEVENT SUMMARY:Examining the Closed Magnetic Field Lines Crossing the Coronal Hol e Boundaries DTSTART;VALUE=DATE-TIME:20230511T075500Z DTEND;VALUE=DATE-TIME:20230511T081000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-342@meetings.aip.de DESCRIPTION:Speakers: Chia-Hsien Lin (Department of Space Science and Engi neering\, National Central University)\nSolar coronal holes (CHs) are the regions with low coronal emissions and an unbalanced magnetic flux\, which led to the common expectation that their magnetic structures are mostly ` `open''\, or\, in other words\, extending to infinity. The objective of th is study is to examine the CH magnetic structures to verify this expectati on. The coronal holes are identified from the synoptic maps constructed us ing the AIA 193 images and HMI line-of-sight magnetograms from 2010 June t o 2020 February. The magnetic structures of the CHs are constructed using the Potential Field Source Surface (PFSS) model. As a comparison\, the dat a from a thermodynamic magnetohydrodynamic (MHD) model are also used. The results from both models reveal that there is a significant percentage of closed field lines extending beyond the CH boundaries\, leading to an unba lanced magnetic flux within the boundaries. The boundary-crossing field li nes tend to be located slightly closer to the CH boundaries\, and are more likely to be found in the lower latitudes during active times. The result s also show that more than 50% (17%) of PF (MHD) CHs do not contain open m agnetic field lines. The CHs without open field lines are often smaller an d less unipolar than those with open field lines.\n\nhttps://meetings.aip. de/event/24/contributions/342/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/342/ END:VEVENT BEGIN:VEVENT SUMMARY:Long-term variability of solar magnetic flux and irradiance DTSTART;VALUE=DATE-TIME:20230511T073000Z DTEND;VALUE=DATE-TIME:20230511T075500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-366@meetings.aip.de DESCRIPTION:Speakers: Natalie Krivova (Max Planck Institute for Solar Syst em Research)\nMeasurements of solar irradiance and surface magnetic flux s ufficiently accurate as to allow assessment of their variability are only available for roughly half a century. Variability on longer time scales is evidenced by proxies. Upon emergence\, the magnetic field on the Sun mani fests itself as dark (sunspots and pores) and bright (faculae/plage and ne twork) features. The combined effect of their evolution and the solar rota tion is the modulation of the solar irradiance. Models relating the variab ility of the solar irradiance to the evolution of the solar surface magnet ic flux account for almost all of the measured variability. Reconstruction s of past variability are\, however\, thwarted by the lack of reliable lon g-term proxies of solar surface magnetism\, in particular those describing bright magnetic features (faculae and network). We will review our recent efforts to improve understanding of the long-term changes in solar magnet ic activity and irradiance. These include recovery and analysis of suitabl e proxies of past solar magnetic activity\, examination of the link betwee n sunspot and facular emergence and evolution\, as well as modelling effor ts to tighten constraints on the long-term solar variability.\n\nhttps://m eetings.aip.de/event/24/contributions/366/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/366/ END:VEVENT BEGIN:VEVENT SUMMARY:Overview of SO/PHI-HRT in the Nominal Mission Phase: data and resu lts DTSTART;VALUE=DATE-TIME:20230508T125000Z DTEND;VALUE=DATE-TIME:20230508T130500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-303@meetings.aip.de DESCRIPTION:Speakers: Daniele Calchetti (Max Planck Insitute for Solar Sys tem Reaserch (MPS))\nThe ESA and NASA Solar Orbiter mission started its no minal mission phase in November 2021. Three perihelions and nine remote se nsing windows have been successfully completed\, providing data from all t he instruments on board the spacecraft. The Polarimetric and Helioseismic Imager (SO/PHI)\, one of Solar Orbiter's remote sensing instruments\, is t he first magnetograph to observe the Sun from outside the Sun-Earth line. Most of the data acquired by the High Resolution Telescope (SO/PHI-HRT) ha s been placed on the Solar Orbiter Archive (SOAR) and are available to the whole scientific community. The excellent polarimetric sensitivity of the instrument and the absence of aberrations induced by the Earth’s atmosp here provide an ideal scenario to study the photospheric dynamics and magn etism of the Sun. The talk will introduce the SO/PHI-HRT instrument and de scribe the data that has been released so far. The processing of the data will also be shortly discussed. We will then present some of the scientifi c cases that have been addressed\, either with standalone observations per formed by the instrument\, or with data combined with observations made by other Solar Orbiter instruments\, or with data gathered by instruments on other spacecrafts or on ground.\n\nhttps://meetings.aip.de/event/24/contr ibutions/303/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/303/ END:VEVENT BEGIN:VEVENT SUMMARY:Exploring the inner heliosphere with combined LOFAR and Solar Orbi ter / Parker Solar Probe observations DTSTART;VALUE=DATE-TIME:20230508T123500Z DTEND;VALUE=DATE-TIME:20230508T125000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-300@meetings.aip.de DESCRIPTION:Speakers: Christian Vocks (Leibniz-Institut für Astrophysik P otsdam (AIP))\nThe phenomena of the active Sun\, like flares and coronal m ass ejections (CMEs)\, have significant influence on Earth and our technic al civilization. This is usually referred to as "Space Weather". Flares an d CMEs accelerate electrons and ions to high energies. These particles are studied both remotely by ground- and space-based telescopes\, and in situ by spacecraft. Energetic electrons emit radio waves as they move through the coronal plasma. This plasma emission is observed by radio telescopes\, e.g. LOFAR. Since the frequency decreases with plasma density higher in t he solar atmosphere\, and radio waves below 10 MHz cannot pass Earth's ion osphere\, spacecraft are needed to continue observations further into inte rplanetary space. They are also required for measuring energetic particles and observations of X-ray emission in the corona. Therefore\, combining L OFAR and spacecraft data provides new insights into the physical processes in the region where the solar corona turns into the solar wind. Parker So lar Probe (PSP) and Solar Orbiter are two missions currently exploring the inner heliosphere. I'll present LOFAR observing campaigns during PSP and Solar Orbiter perihelia\, that cover the Sun and it's surroundings by maki ng use of LOFAR's capability of running multiple observing modes in parall el\, and show how they connect the corona with the heliosphere.\n\nhttps:/ /meetings.aip.de/event/24/contributions/300/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/300/ END:VEVENT BEGIN:VEVENT SUMMARY:The European Solar Telescope (EST): instruments and science DTSTART;VALUE=DATE-TIME:20230508T121000Z DTEND;VALUE=DATE-TIME:20230508T123500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-365@meetings.aip.de DESCRIPTION:Speakers: Rolf Schlichenmaier (Leibniz-Institut für Sonnenphy sik (KIS))\nThe EST is a project aimed at studying the dynamic magnetic co nnectivity of the solar atmosphere\, from the deep photosphere to the uppe r chromosphere. A polarimetrically compensated telescope with integrated m ulti-conjugated adaptive optics will feed a suite of spectropolarimetric i nstruments that allows to simultaneously observe the different layers of t he solar atmosphere. In this talk\, I will present the concept for the lig ht distribution and the instrument suite which intends to significantly im prove our capabilities to address critical science cases in our field such as: How does the magnetic field emerge into the photosphere? How does it evolve\, interact\, and rise in a convectively stable stratification? What is the interplay between the magnetic field\, reconnection processes\, ra diation\, waves\, and the transport of energy into higher layers?\n\nhttps ://meetings.aip.de/event/24/contributions/365/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/365/ END:VEVENT BEGIN:VEVENT SUMMARY:Welcome DTSTART;VALUE=DATE-TIME:20230508T120000Z DTEND;VALUE=DATE-TIME:20230508T121000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-415@meetings.aip.de DESCRIPTION:https://meetings.aip.de/event/24/contributions/415/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/415/ END:VEVENT BEGIN:VEVENT SUMMARY:DKIST instruments and science DTSTART;VALUE=DATE-TIME:20230511T091000Z DTEND;VALUE=DATE-TIME:20230511T093500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-407@meetings.aip.de DESCRIPTION:Speakers: Thomas Rimmele (National Solar Observatory)\nhttps:/ /meetings.aip.de/event/24/contributions/407/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/407/ END:VEVENT BEGIN:VEVENT SUMMARY:Coronal flux ropes over Solar Cycle 24 DTSTART;VALUE=DATE-TIME:20230508T130500Z DTEND;VALUE=DATE-TIME:20230508T133000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-355@meetings.aip.de DESCRIPTION:Speakers: Anthony Yeates (Durham University)\nQuasi-static mod elling of the Sun’s corona using the magneto-frictional approximation ma kes predictions of how its large-scale magnetic structure might vary over the solar cycle. Unlike the traditional potential field source surface mod el\, this approach is able to probe the effects of low coronal electric cu rrents and the corresponding free magnetic energy. In particular\, ongoing footpoint shearing and flux cancellation lead to the concentration of fre e energy within closed-field regions\, naturally forming sheared arcades a nd magnetic flux ropes. I will show model results for Cycle 24 driven by m agnetogram data from SDO/HMI\, with the aim of comparing to earlier result s from a decade ago for Cycle 23. In particular\, we will consider how sol ar flux ropes and their eruptions vary over the solar cycle\, at least acc ording to this model.\n\nhttps://meetings.aip.de/event/24/contributions/35 5/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/355/ END:VEVENT BEGIN:VEVENT SUMMARY:On the origin of the Solar Mean Magnetic Field DTSTART;VALUE=DATE-TIME:20230511T130000Z DTEND;VALUE=DATE-TIME:20230511T131500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-346@meetings.aip.de DESCRIPTION:Speakers: Vishnu M (Indian Institute of Astrophysics)\nThe Sol ar Mean Magnetic Field (SMMF) is the average value of the line-of-sight (L OS) magnetic field considered over the visible hemisphere of the Sun. Vari ous synoptic observations of the solar magnetic field have shown that the SMMF has a periodicity of ~ 27 days\, and an amplitude that varies accordi ng to the solar cycle\, from ±0.2 G during solar minima to ±2 G during s olar maxima. It has also been shown that the SMMF has a good correlation w ith the Interplanetary Magnetic Field (IMF). Nevertheless\, the origin of the SMMF is still a controversial subject. Till date\, SMMF measurements h ave always been carried out using photospheric spectral lines only. In thi s regard\, we utilised full-disk LOS magnetograms from the Vector Spectrom agnetograph (VSM) (one of the instruments in SOLIS - Synoptic Optical Long -term Investigations of the Sun)\, calculated the SMMF as the disk-average d magnetic field in each magnetogram\, and compared the SMMF at photospher ic and chromospheric heights. Our comparison showed that the SMMF at the c hromosphere is a factor of 0.6 times the SMMF at the photosphere\, with a correlation coefficient of 0.80\; indicating that a considerable fraction of the SMMF might be propagating outwards from the photosphere to the chro mosphere. This brings us one step closer to understanding the connection b etween the SMMF and the IMF. Further\, to understand the origin of the SMM F\, which is a magnetic flux imbalance\, we are studying the full-disk Sto kes I and Stokes V data from VSM\, which are disk-averaged to create Stoke s profiles. Any localised source of the SMMF should reflect in the Stokes V profile as a rotationally modulated doppler shift. Our initial analyses show that there is a periodicity in the Stokes V doppler shift. This perio dicity is being analysed along with associated magnetograms\, to understan d the source of the SMMF.\n\nhttps://meetings.aip.de/event/24/contribution s/346/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/346/ END:VEVENT BEGIN:VEVENT SUMMARY:The effects of the surface inflows on quenching of solar cycles DTSTART;VALUE=DATE-TIME:20230511T124500Z DTEND;VALUE=DATE-TIME:20230511T130000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-345@meetings.aip.de DESCRIPTION:Speakers: MOHAMMED TALAFHA (Dept. of Space Physics and Technol ogy\, Wigner Research Centre for Physics)\nRecently\, there has been consi deration of two possible methods for the nonlinear modulation of solar cyc le amplitudes. The first mechanism\, known as Tilt Quenching (TQ)\, involv es a negative feedback relationship between the cycle amplitude and the me an tilt angle of bipolar active regions relative to the azimuthal directio n. The second mechanism\, known as Latitude Quenching (LQ)\, involves a po sitive correlation between the average emergence latitude of active region s and the cycle amplitude.\nHere we study the effects of quenching paramet ers on the Surface Flux Transport (SFT) models and the effects of implemen ting the surface inflows into the SFT models on the two different observab le nonlinearities: TQ and LQ \nOur SFT models are grid-based. We have meth odically investigated the extent of nonlinearity caused by TQ and LQ\, as well as their combination in the presence of surface inflows.\nA prelimina ry result is that there is a linear dependence of quenching parameters on the dipole moment. This is expected from the model. A second finding is th at the effects of introducing surface inflows to the SFT models will produ ce lower values of dipole moments for the different cases of quenching in the solar cycle.\n\nhttps://meetings.aip.de/event/24/contributions/345/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/345/ END:VEVENT BEGIN:VEVENT SUMMARY:Differential Rotation of the Solar Chromosphere using multidecadal Ca K spectroheliograms DTSTART;VALUE=DATE-TIME:20230511T123000Z DTEND;VALUE=DATE-TIME:20230511T124500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-343@meetings.aip.de DESCRIPTION:Speakers: Dibya Kirti Mishra (ARIES\, India)\nDifferential rot ation is a key aspect of the solar dynamo model and is well-established in the Sun's interior and photosphere. However\, our understanding of the ch romosphere and upper atmosphere's differential rotation is limited and has yielded contradictory results in previous studies. To address this\, we u tilized a century-long dataset of Ca II K images (1907-2007) from the Koda ikanal Solar Observatory (KoSO) to investigate the chromosphere's rotation profile during different solar cycles. By employing the image correlation analysis on sets of consecutive day images\, we found that the chromosphe re rotates 1.52% faster than the photosphere but with less differential ro tation compared to the photosphere values. To validate our method and resu lts\, we applied the same technique to MDI white light data and other Ca I I K data sources (Meudon and PSPT/Rome) and obtained consistent results. M oreover\, we examined the solar cycle dependence of differential rotation parameters and investigated the north-south asymmetry of the solar rotatio n profile.\n\nhttps://meetings.aip.de/event/24/contributions/343/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/343/ END:VEVENT BEGIN:VEVENT SUMMARY:Revisiting the long-term evolution of the Sun’s magnetic field: Solar wind sources and coronal rotation DTSTART;VALUE=DATE-TIME:20230511T121500Z DTEND;VALUE=DATE-TIME:20230511T123000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-347@meetings.aip.de DESCRIPTION:Speakers: Adam Finley (CEA Paris-Saclay)\nThe Sun’s large-sc ale magnetic field undergoes periodic reversals due to the activity of the dynamo within the solar interior. The evolution of the Sun’s magnetic f ield has a clear impact on the structure of the corona and solar wind abov e. Here we show results from the spherical harmonic decomposition of the S un’s photospheric magnetic field\, using WSO\, SOHO/MDI and SDO/HMI syno ptic magnetograms that span sunspot cycles 21-24\, plus cycle 25 to presen t. From this\, trends in the magnetic field components (notably the lowest order\, dipole\, quadrupole and octupole) are extracted and compared betw een cycles. In addition\, we perform potential field source surface modeli ng of the coronal magnetic field\, in order to make inferences about the s olar wind sources and likely coronal rotation rate. These results are comp ared against scattered whitelight observations of the corona from MLSO/K-C or and SOHO/LASCO-C2. The role of nested flux emergence and poleward surge s of magnetic flux will be discussed in this context\, with future links t o heliospheric missions like Solar Orbiter and Parker Solar Probe.\n\nhttp s://meetings.aip.de/event/24/contributions/347/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/347/ END:VEVENT BEGIN:VEVENT SUMMARY:Solar Irradiance Variability - From Measurements to Modelling DTSTART;VALUE=DATE-TIME:20230511T115000Z DTEND;VALUE=DATE-TIME:20230511T121500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-360@meetings.aip.de DESCRIPTION:Speakers: Margit Haberreiter (PMOD/WRC)\nThe total and spectra l solar irradiance\, TSI and SSI\, respectively\, vary on many timescales from sub-daily variations to annual\, decadal\, centennial timescales. The variations of the SSI are also wavelength dependent\, with larger relativ e variations in the EUV/UV and smaller variations in the visible and IR. T hese irradiance variations allow us to understand\, on the one hand\, the physics of the Sun as a star and\, on the other hand\, the key energy sour ce for the Earth's climate system. In this talk I will review the availabl e irradiance measurements\, composite datasets\, models and how the underl ying physics\, which drives the irradiance variations\, is implemented.\n\ nhttps://meetings.aip.de/event/24/contributions/360/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/360/ END:VEVENT BEGIN:VEVENT SUMMARY:Net electric currents\, flares\, CMEs and the evolution of active regions DTSTART;VALUE=DATE-TIME:20230510T140500Z DTEND;VALUE=DATE-TIME:20230510T142000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-329@meetings.aip.de DESCRIPTION:Speakers: Ioannis Kontogiannis (Leibniz Institute for Astrophy sics Potsdam (AIP) Germant)\nThe build-up of magnetic energy during flux e mergence\, which powers flares and coronal mass ejections (CME)\, requires the presence of significant amounts of volume electric currents. Measurin g these electric currents requires knowledge of the magnetic field vector in three dimensions in the solar atmosphere. However\, systematic high-qua lity spectropolarimetric observations are constrained at the photosphere. Thus\, only the vertical component of the electric current density\, *Jz*\ , can be routinely calculated by means of differentiation of the photosphe ric magnetic field vector. In this work\, a different method\, relying on image segmentation and taking into account observational and numerical err ors\, is employed to determine the total unsigned non-neutralized (net) el ectric currents\, *INN\,tot*\, injected to the corona. This quantity devia tes from *Jz* and is more closely associated to the development of strongl y sheared polarity inversion lines (PIL). It is found that *INN\,tot* is a t least one order of magnitude higher for flare productive active regions and its temporal evolution from emergence to decay exhibits intricate stru cture\, owing to the interaction between opposite magnetic polarities and the formation of PILs. Further relevant quantities facilitate the distinct ion between imminent eruptive and confined major flares and they are stron gly correlated with the kinematic characteristics of subsequent CMEs. Thes e quantities are examined during the emergence and pre-eruptive evolution of active regions and their association with the magnetic complexity of ac tive regions.\n\nhttps://meetings.aip.de/event/24/contributions/329/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/329/ END:VEVENT BEGIN:VEVENT SUMMARY:Chromospheric evaporation by particle beams in multi-dimensional f lare models DTSTART;VALUE=DATE-TIME:20230510T135000Z DTEND;VALUE=DATE-TIME:20230510T140500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-323@meetings.aip.de DESCRIPTION:Speakers: Malcolm Druett (KU Leuven)\nOne-dimensional (1D) mod els of solar flares often generate hot upflows from the chromosphere (chro mospheric evaporation) due to heating by energetic particle beams (Allred et al. 2005\, 2015\, Druett et al. 2017\, Polito et al. 2023). The beams o f particles are injected at the top of the models using distributions cons istent with X-ray emission in observations assumed to result from Bremsstr ahlung emission from energetic particle beams impacting the ambient plasma . To date\, 2D and 3D flare models produce evaporation as a result of ther mal conduction and the delivery of kinetic energy to the lower atmosphere from the outflows of reconnection jets (e.g. Ruan et al. 2020). In this st udy we evaluate and explore the reasons for this difference compare the di fferences between the findings of 1D and multi-dimensional flare models. W e report the first simulation of chromospheric evaporation in a multi-dime nsional model caused by beam electrons.\n\nhttps://meetings.aip.de/event/2 4/contributions/323/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/323/ END:VEVENT BEGIN:VEVENT SUMMARY:Picoflares in the Quiet Solar Corona DTSTART;VALUE=DATE-TIME:20230510T133500Z DTEND;VALUE=DATE-TIME:20230510T135000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-325@meetings.aip.de DESCRIPTION:Speakers: Olena Podladchikova (The Leibniz Institute for Astro physics Potsdam (AIP))\nOn May 30\, 2020\, the Solar Orbiter High-Resoluti on Imager operating in 174 A being for the first time approximately at a half AU to the Sun\, registered a large number of short\, small-scale heat ing events\, often called campfires\, with rich morphology and smaller spa ce-time characteristics than nanoflares. We estimate the thermal energy of the heating events from increases in the emission measure and temperature using methods assessing thermal energy in flares. We compare these with t he characteristics of X-ray flares\, in particular\, those recorded by the X-ray spectrometer/telescope onboard Solar Orbiter. We found campfires e mit thermal energy in picoflares range. The additional previously unaccoun ted energy input of is about 1% to the total required to sustain quiet sol ar corona power. The observed frequency distribution would have to continu e to the femtoflares range to fulfill the observed heating requirement. We explain the existence of solar flares below the expected nanoflare thresh old as follows. They originate in small coronal loops of 200-5000 km\, sma ller than considered by Parker. Some picoflares show only a partial energy release along a single loop.\n\nhttps://meetings.aip.de/event/24/contribu tions/325/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/325/ END:VEVENT BEGIN:VEVENT SUMMARY:Multiwavelength observations of small-scale eruptive phenomena in an arch filament system DTSTART;VALUE=DATE-TIME:20230510T132000Z DTEND;VALUE=DATE-TIME:20230510T133500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-332@meetings.aip.de DESCRIPTION:Speakers: Salvo Guglielmino (Istituto Nazionale di Astrofisica (INAF))\nRecent ultraviolet observations performed by the IRIS satellite have shown the occurrence of small-scale eruptive phenomena\, characterize d by significant increase of the integrated line intensity (up to a factor of 100 in Si IV lines) and of the line width (up to ± 100 km s$^{-1}$)\, likely due to magnetic reconnection. Some of these events also exhibit co unterpart in all the SDO/AIA channels.\nWe report on a series of similar e vents observed during secondary flux emergence in an arch filament system in active region NOAA 12585. We use high-resolution observations acquired by SST/CRISP relevant to the photosphere and the chromosphere to character ize the magnetic field configuration and the phenomena occurring in the lo w atmosphere. IRIS and SDO/AIA observations reveal the atmospheric respons e and the presence of heating and plasma ejection activity in the upper at mosphere.\n\nhttps://meetings.aip.de/event/24/contributions/332/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/332/ END:VEVENT BEGIN:VEVENT SUMMARY:Comprehensive simulation of a solar prominence with MURaM DTSTART;VALUE=DATE-TIME:20230510T130500Z DTEND;VALUE=DATE-TIME:20230510T132000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-328@meetings.aip.de DESCRIPTION:Speakers: Lisa-Marie Zessner (Max Planck Institute for Solar S ystem Research)\nSolar prominences consist of cool and dense plasma that i s suspended in the corona\, surrounded by hotter and less dense coronal ma terial. As predecessors of coronal mass ejections\, solar prominences are important drivers of space weather\, but their exact formation mechanism i s still unknown. We use the radiative magnetohydrodynamic code MURaM to si mulate the formation and dynamics of a prominence in the solar atmosphere. MURaM includes the relevant physical processes to realistically simulate the solar photosphere\, chromosphere and corona.\n\nWe create a stable dip ped magnetic field configuration in a 3D box of size 80 x 30 x 10 Mm and l et it evolve. In the course of the simulation\, a dense plasma seed ejecte d from the chromosphere randomly settles into a magnetic dip and is cooled by radiative losses. The resulting pressure drop drives a strong flow of plasma into the feature and builds up a cool\, long-lasting structure in t he solar corona. This prominence is very dynamic but stable due to the sta bility of the underlying magnetic field. Its properties and dynamics are c omparable to certain observations of real prominences. In this contributio n\, we present the formation mechanism and properties of the simulated pro minence.\n\nhttps://meetings.aip.de/event/24/contributions/328/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/328/ END:VEVENT BEGIN:VEVENT SUMMARY:On the detection of two X-class solar flares in the Sun-as-a-star with the HARPS solar telescope DTSTART;VALUE=DATE-TIME:20230510T125000Z DTEND;VALUE=DATE-TIME:20230510T130500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-298@meetings.aip.de DESCRIPTION:Speakers: Alex Pietrow (AIP)\nSun-as-a-star observations provi de a valuable link between resolved solar observations and disk-integrated stellar observations\, as it gives a unique insight into how well-defined solar activity affects the average spectrum. This activity can affect the integrated spectrum in complex ways\, and therefore the values of for exa mple reference spectra and exoplanet characterizations. It is therefore im portant to understand the magnitude and timescale of these variations. We aim to contribute to this field by focusing on the most rapidly changing type of activity: solar flares. We present the first Sun-as-a-star detecti on of solar flares with TNG/HARPS\, and discuss its effects on the integra ted spectrum. When combined with observations made with SST/CRISP&CHROMIS and SDO/AIA\, we are able to point to several evolutionary features of the flares in the HARPS data\, as well as discuss their imprints on activity indices and RV measurements.\n\nhttps://meetings.aip.de/event/24/contribut ions/298/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/298/ END:VEVENT BEGIN:VEVENT SUMMARY:Photospheric and Chromospheric Magnetic Field Evolution during the X1.6 Flare in NOAA 12192 DTSTART;VALUE=DATE-TIME:20230510T123500Z DTEND;VALUE=DATE-TIME:20230510T125000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-327@meetings.aip.de DESCRIPTION:Speakers: Fabiana Ferrente (University of Catania)\nThe X1.6 f lare observed on 22 October 2014 was one of the strongest flares observed in the complex active region NOAA 12192. We report on observations acquire d in the Fe I 617.30 nm and Ca II 854.2nm line profiles by the Interferome tric BIdimensional Spectropolarimeter (IBIS) immediately after the peak of the X1.6 flare. We focused on the chromospheric signals and studied the t emporal variation of the line of sight (LOS) magnetic field\, using the We ak-Field Approximation (WFA). Our results show that stepwise variations oc curred at specific locations along the eastern flare ribbon\, during the t ail of the flare impulsive phase. This result was validated by the STiC in version of the pixels used for the WFA analysis. We also investigated the photospheric magnetic field obtaining that the LOS magnetic field did not exhibit the same stepwise changes observed in the chromosphere in the sele cted pixels. Finally\, we found no clear evidence of changes along the pol arity inversion line around a magnetic polarity intrusion\, which is almos t cospatial to the area affected by the initial energy release.\n\nhttps:/ /meetings.aip.de/event/24/contributions/327/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/327/ END:VEVENT BEGIN:VEVENT SUMMARY:The many scales observed by EUI onboard Solar Orbiter DTSTART;VALUE=DATE-TIME:20230510T121000Z DTEND;VALUE=DATE-TIME:20230510T123500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-364@meetings.aip.de DESCRIPTION:Speakers: David Berghmans (Royal Observatory of Belgium)\nEUI is a set of (E)UV imaging telescopes that observe the solar corona from >1 0 Rsun scales down to pixel scales of 100 km. EUI has been embarked on the ESA/NASA Solar Orbiter mission on a 10-year mission\, while the imaging c adence can be as fast as 2s. This wide range of spatial and temporal scale s allows to observe the scale invariance of events\, from the largest to t he smallest flares\, and from the largest eruptions to the smallest jets. Besides identifiable events\, also the background spatial structuring show s scale invariance over several orders of magnitude. In this presentation we will present the newest contributions of EUI at the smallest scales (pi coflares\, picojets) and discuss limitations on how much further down this coronal scale invariance can extend.\n\nhttps://meetings.aip.de/event/24/ contributions/364/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/364/ END:VEVENT BEGIN:VEVENT SUMMARY:The role of the chromospheric canopy in the formation of a penumbr a DTSTART;VALUE=DATE-TIME:20230509T131000Z DTEND;VALUE=DATE-TIME:20230509T132500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-312@meetings.aip.de DESCRIPTION:Speakers: Philip Lindner (Leibniz-Institut fuer Sonnenphysik ( KIS))\nWhile it is being conjectured that a chromospheric canopy plays a r ole in penumbra formation\, it has been difficult to find observational ev idence of the connectivity between the photosphere and the chromosphere. \ n\nWe investigate the existence of a chromospheric canopy as a necessary c ondition for the formation of a penumbra and aim to find the origin of the inclined magnetic fields. Spectropolarimetric observations of NOAA AR 127 76 from the GRIS@GREGOR instrument were analyzed. Atmospheric parameters w ere obtained from the deep photospheric Ca I 10839 Å line (VFISV inversio n code)\, the mostly photospheric Si I 10827 Å line (SIR inversion code) and the chromospheric He I 10830 Å triplet (HAZEL inversion code). \n\nIn the deepest atmospheric layers\, we find that the magnetic properties (in clination and field strength distribution) measured on the sunspot sector with fully fledged penumbra are similar to those measured on the sector wi thout penumbra. Yet\, in higher layers\, magnetic properties are different . In the region showing no penumbra\, almost vertical chromospheric magnet ic fields are observed. Additionally\, thin filamentary structures with a maximum width of 0.1 arcsec are seen in photospheric high-resolution TiO-b and images in this region. \n\nThe existence of a penumbra is found to be discriminated by the conditions in the chromosphere. This indicates that a chromospheric canopy is a necessary condition for the formation of a penu mbra. However\, our results demonstrate that inclined fields in the chromo spheric canopy are not needed for the development of inclined fields in th e photosphere. We question the `fallen-magnetic-flux-tubes' penumbra forma tion scenario and favor a scenario\, in which inclined fields emerge from below the surface and are blocked by the overlying chromospheric canopy.\n \nhttps://meetings.aip.de/event/24/contributions/312/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/312/ END:VEVENT BEGIN:VEVENT SUMMARY:Active region evolution – Tracking active regions from the near- Earth side to the solar far side (and back) DTSTART;VALUE=DATE-TIME:20230509T125500Z DTEND;VALUE=DATE-TIME:20230509T131000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-313@meetings.aip.de DESCRIPTION:Speakers: Hanna Strecker (Instituto de Astrofísica de Andaluc ía ((IAA-CSIC) & Spanish Space Solar Physics Consortium)\nFor a long time \, the study of the evolution of active regions in the solar photosphere h as been limited by the transit time of the active regions over the solar d isk as seen from Earth. Since its launch in February 2020\, ESA/NASA's Sol ar Orbiter spacecraft provides us\, from time to time\, with the possibili ty to see the solar far side. The Polarimetric and Helioseismic Imager (SO /PHI)\, one of its ten instruments\, delivers data of the solar photospher e in intensity and vector magnetic field. In February 2021\, during Solar Orbiter’s first superior conjunction\, the full disk telescope of SO/PHI acquired the first polarimetric data of the photospheric solar far side. We combine this data with data from the Helioseismic and Magnetic Imager ( HMI) flying on board NASA’s Solar Dynamic Observatory. This enables an a lmost 360º view of the Sun and allows\, for the first time\, the tracking of active regions over a full solar rotation almost without interruption\ , from the near-Earth side to the far side. We study the evolution of four active regions in intensity and LOS magnetograms while they rotate from t he near-Earth side\, seen by HMI\, to the solar far side\, into the field- of-view (FOV) seen by SO/PHI. Three of the active regions decay on the sol ar far side and do not show any signal in intensity when reaching the FOV of SO/PHI. One active region crosses the disk as seen from Earth while app earing to decay. However\, new flux emerges on the solar far side leading to the development of pores and a small sunspot before the region reaches the limb as seen in SO/PHI and reappears on the near-Earth side. We will p resent the longest almost uninterrupted study of the evolution of the magn etic field of active regions\, achieved so far. This demonstrates the uniq ueness of combining Solar Orbiter and near-Earth side observations to cont inuously study the evolution of active regions from their emergence to the ir decay.\n\nhttps://meetings.aip.de/event/24/contributions/313/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/313/ END:VEVENT BEGIN:VEVENT SUMMARY:Quantifying Systematic Biases in the Measurements of the Open Magn etic Flux DTSTART;VALUE=DATE-TIME:20230509T124000Z DTEND;VALUE=DATE-TIME:20230509T125500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-307@meetings.aip.de DESCRIPTION:Speakers: Ivan Milic (Leibniz Institute for Solar Physics (KIS ))\nOpen magnetic flux in the photosphere\, especially at the poles\, pres ents an important boundary condition for modeling the heliospheric field. The field extrapolated from polar observations is roughly 50% lower than t he in-situ measurements (“open flux problem”). Here we present our eff orts to characterize biases in the open flux inference and that way explai n the discrepancy above. We use a state-of-the-art plage-like MURaM MHD si mulation of the solar photosphere to model polarized spectra of magnetical ly sensitive Fe I 630 nm doublet lines\, observed by the Hinode SOT/SP ins trument. We mimic the realistic observation at the disk center and the pol e by calculating emergent intensity\, applying instrumental effects (spat ial and spectral PSF\, binning)\, and adding the photon noise. We then app ly different inversion codes built upon different physical assumptions to these synthetic observations and compare results to the original simulatio n.\n\nAt the disk center\, a significant fraction (20\, down to 50%) of op en flux gets lost for the telescopes with apertures smaller than 1m. At th e pole\, the magnetic field disambiguation becomes a critical part: the as sumption of the radial field underestimates flux by around 30% while the i nclusion of the telescope PSF further exacerbates the problem. The more in -depth investigation that accounts for stray light still yields significan t discrepancies between the original and inferred intrinsic properties of the magnetic field. These systematic errors in field diagnostics may be re duced by high-resolution or out-of-ecliptic observations.\n\nhttps://meeti ngs.aip.de/event/24/contributions/307/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/307/ END:VEVENT BEGIN:VEVENT SUMMARY:Stereoscopic disambiguation of vector magnetograms: first applicat ions to HRT data DTSTART;VALUE=DATE-TIME:20230509T122500Z DTEND;VALUE=DATE-TIME:20230509T124000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-304@meetings.aip.de DESCRIPTION:Speakers: Gherardo Valori (MPS - Max Planck Institute for Sola r System Research)\nSpectropolarimetric reconstructions of the photospheri c vector magnetic field are intrinsically limited by the 180-degree-ambigu ity in the orientation of the transverse component. So far\, the removal of such an ambiguity has required assumptions about the properties of the photospheric field\, which makes disambiguation methods model-dependent.\n \nThe successful launch and operation of Solar Orbiter have made the remov al of the 180-ambiguity possible solely using observations of the same loc ation on the Sun obtained from two different vantage points. To that purpo se\, the Stereoscopic Disambiguation Method was recently developed and suc cessfully tested on numerical simulations.\n\nHere we present the first ap plication of the SDM to data obtained by the High Resolution Telescope (HR T) onboard Solar Orbiter during the March 2022 campaign\, when the angle w ith Earth was 27 degrees. The method is successfully applied to remove the ambiguity in the transverse component of the HRT vector magnetogram solel y using observations (from HRT and from the Helioseismic and Magnetic Imag er-HMI)\, for the first time.\n\nThe SDM is proven to provide observation- only disambiguated vector magnetograms that are spatially homogeneous and consistent.\nWhile we present here an application combining PHI with HMI d ata\, the same method can be applied to magnetic information from Solar Or biter together with any Earth-bound observatory.\n\nhttps://meetings.aip.d e/event/24/contributions/304/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/304/ END:VEVENT BEGIN:VEVENT SUMMARY:Modeling of the solar chromosphere DTSTART;VALUE=DATE-TIME:20230509T120000Z DTEND;VALUE=DATE-TIME:20230509T122500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-357@meetings.aip.de DESCRIPTION:Speakers: Sanja Danilovic (Sanja)\nThe chromosphere is a dynam ic and complex layer where all the relevant physical processes happen on v ery small spatio-temporal scales. A few spectral lines that can be used as chromospheric diagnostics\, give us convoluted information that is hard t o interpret without realistic theoretical models. What are the key ingredi ents that these models need to contain? In this review\, we present the re cent numerical models and how they compare to observations. We will discus s the formation and properties of chromospheric structures at different sp atial scales and the challenges we meet when modeling the solar chromosphe re.\n\nhttps://meetings.aip.de/event/24/contributions/357/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/357/ END:VEVENT BEGIN:VEVENT SUMMARY:Comparative Study of Power Distribution in Flaring and Non-flaring Active Regions with SDO/AIA. DTSTART;VALUE=DATE-TIME:20230511T070000Z DTEND;VALUE=DATE-TIME:20230511T071500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-335@meetings.aip.de DESCRIPTION:Speakers: Aneta Wisniewska (Leibniz Institute for Astrophysics Potsdam (AIP))\nObservational precursors of small-scale solar flares prov ide a basis information for future operational systems for large events fo recasting. We present the results of observational comparative study of th e active flaring (AFR) and non-flaring regions (ANFR). We study power spec tral density (PSD) of the intensity signal in the level of solar chromosph ere and corona\, through 2D-spatial maps of the power estimated for seven active regions\, using intensity data from Atmospheric Imaging Assembly (A IA) on board Solar Dynamics Observatory (SDO). We selected six active regi ons with pore or sunspot feature\, and magnetic class of α\, β\, γ (acc ording to the Hale' magnetic classification system). The selected data are analysed in four wavelengths: 1700Å and 193Å\, 171Å\, and 131Å. This very fast method of analysis based on 2D-Fourier Power Maps (FPM) and the Wavelet Power Spectrum (WPS) of individual pixels spatially resolved in th e flare location.\n\nhttps://meetings.aip.de/event/24/contributions/335/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/335/ END:VEVENT BEGIN:VEVENT SUMMARY:Quantifying Poynting Flux in the Quiet Sun Photosphere Using Obser vations and Simulations DTSTART;VALUE=DATE-TIME:20230510T071500Z DTEND;VALUE=DATE-TIME:20230510T073000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-317@meetings.aip.de DESCRIPTION:Speakers: Denis Tilipman (University of Colorado\, Boulder\; N ational Solar Observatory (NSO))\nThe solar chromosphere and corona are he ated by the dissipation of magnetic energy that emerges from the photosphe re. The outward flux of magnetic energy\, or Poynting flux\, is therefore important to understand in both qualitative and quantitative terms. It can be computed by taking a cross product of electric and magnetic fields\, a nd in ideal MHD conditions it can be expressed in terms of magnetic field and plasma velocity. There are existing estimates of Poynting flux in acti ve regions and plages\, but the quiet Sun (QS) remains a challenging targe t due to resolution effects and polarimetric noise. However\, with upcomin g DKIST capabilities\, these estimates will become more feasible than ever before.\n\nHere we present our findings from studying QS Poynting flux in Sunrise/IMaX observations and MURaM simulations. Since this problem has n ot been comprehensively approached before\, and due to the aforementioned challenges of QS observations\, we explore and evaluate multiple methods f or computing Poynting flux. For transverse velocities\, we try two inversi on methods – a classic correlation tracking approach FLCT and a neural n etwork based method DeepVel – and show DeepVel to be the more suitable m ethod in the context of small-scale QS flows. Further\, we investigate the effect of magnetic field azimuthal ambiguity on Poynting flux estimates\, and we describe a new method for azimuth disambiguation. Finally\, we use two methods for obtaining the electric field. The first method relies on idealized Ohm's law\, whereas the second is a state-of-the-art inductive e lectric field inversion method PDFI\\_SS.\n\nWe compare the resulting Poyn ting flux values with theoretical estimates for chromospheric and coronal energy losses and find that some\, but not all\, of Poynting flux estimate s are sufficient to match the energy losses. Using MURaM simulations\, we show that photospheric Poynting fluxes vary with optical depth\, and that there is an observational bias that results in underestimated Poynting flu xes due to unaccounted shear term contribution.\n\nhttps://meetings.aip.de /event/24/contributions/317/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/317/ END:VEVENT BEGIN:VEVENT SUMMARY:Changes in the Lower Solar Atmosphere throughout the Solar Cycle DTSTART;VALUE=DATE-TIME:20230512T070000Z DTEND;VALUE=DATE-TIME:20230512T071500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-344@meetings.aip.de DESCRIPTION:Speakers: James Crowley (National Solar Observatory\; Universi ty of Colorado\, Boulder)\nThe change in the distribution of the magnetic field in the quiet Sun photosphere over the solar cycle could be expected to cause systematic variations in the photospheric thermodynamic structure . This could be due to changes in the dynamics of the convective overshoot or radiative properties. To look for such changes\, we use high spatial a nd spectral resolution spectropolarimetric observations obtained by Hinode SOT and apply the Spectropolarimetric Inversions Based on Response Functi ons (SIR) code to infer physical conditions in the lower solar photosphere . By using multiple homogeneous datasets acquired over 15 years\, we analy ze the distributions of the inferred parameters in the granules and interg ranules of magnetic and non-magnetic spectra throughout the solar cycle. T he final goal of our study is to characterize changes in the inferred atmo spheric parameters\, notably\, the temperature structure\, the line-of-sig ht velocities\, and magnetic properties.\n\nhttps://meetings.aip.de/event/ 24/contributions/344/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/344/ END:VEVENT BEGIN:VEVENT SUMMARY:Formation of MgII h&k spectra in an enhanced network region simula ted with MURaM DTSTART;VALUE=DATE-TIME:20230511T071500Z DTEND;VALUE=DATE-TIME:20230511T073000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-336@meetings.aip.de DESCRIPTION:Speakers: Patrick Ondratschek (Max Planck Institute for Solar System Research)\nUnderstanding the physical processes in the solar chromo sphere requires comprehensive models which can be compared to observations . These models include the treatment of magnetic fields\, heat conduction and radiative transfer (RT). However\, usually models fail to reproduce ob served properties of chromospheric spectral lines. The MgII h&k lines form in the middle to upper chromosphere and are observed by the IRIS satellit e mission with high precision. The forward modeled spectral lines appear o n average to have too narrow line widths and larger peak asymmetries than the observations.\n We use the recently developed chromospheric extension of the radiative MHD code MURaM to simulate an enhanced network (EN) regio n. From the resulting modeled atmospheres we use the RT codes RH1.5D and M ulti3D to synthesize the MgII h&k lines in 1D and 3D RT. We find that the line width as well as the peak separations from the forward modeled spectr a are on average larger and in better agreement to observations. We discus s the physical properties such as velocity gradients and density stratific ation in the chromosphere of the modeled atmosphere that lead to the impro ved synthetic spectral profiles.\n\nhttps://meetings.aip.de/event/24/contr ibutions/336/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/336/ END:VEVENT BEGIN:VEVENT SUMMARY:Center-to-limb variation in Mg II intensities in quiet Sun and act ive regions from IRIS DTSTART;VALUE=DATE-TIME:20230510T070000Z DTEND;VALUE=DATE-TIME:20230510T071500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-318@meetings.aip.de DESCRIPTION:Speakers: Megha Anand (nter University Centre for Astronomy an d Astrophysics\, Post Bag-4\, Ganeshkhind\, Pune 411007\, India)\nThe sola r ultraviolet (UV) and extreme ultraviolet (EUV) radiations which are majo r contributors to the solar spectral irradiance (SSI) below 4000 Å\, sig nificantly affect the composition and the thermal structure of the Earth's atmosphere. The Magnesium II core-to-wing ratio (also known as the Mg II index) is one of the best proxies for solar activity and UV-SSI variabilit y. To date\, the Mg II index has been studied\, assuming Sun-as-a-star usi ng low (11 Å) and medium spectral resolution (1 Å) data. On the other ha nd\, Mg II h and k line pairs being optically thick\, are highly sensitive to the thermodynamical properties of the line-forming region and the view ing angle. Therefore\, in this study\, we explore the center-to-limb varia tion (CLV) in the Mg II line and continuum intensities in various solar fe atures like quiet Sun (QS)\, plage\, inter-plage\, sunspot umbra\, and pen umbra using the high spatial and spectral resolution data from the Interfa ce Region Imaging Spectrometer (IRIS). Our study indicates that plages wit h the lowest magnetic field density show the highest limb darkening as opp osed to the QS\, whereas the umbra and penumbra show a combination of both limb darkening and brightening depending on their photospheric magnetic f ield densities. This would provide us an opportunity to understand the imp ortance of the spatially resolved Mg II index on the SSI studies.\n\nhttps ://meetings.aip.de/event/24/contributions/318/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/318/ END:VEVENT BEGIN:VEVENT SUMMARY:Atomic lines parameters inference using a global spectropolarimetr ic inversion DTSTART;VALUE=DATE-TIME:20230512T075500Z DTEND;VALUE=DATE-TIME:20230512T081000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-348@meetings.aip.de DESCRIPTION:Speakers: Dušan Vukadinović (Max Planck Institute for Solar System Research)\nMany solar spectral lines have poorly determined atomic parameters\, such as the transition probability or the central wavelength\ , especially in the near-ultraviolet (NUV) range. We present a novel appro ach to exploit high-angular-resolution spectropolarimetric observations of the Sun to obtain precise atomic parameters of spectral lines\, required for the proper analysis of solar and stellar observations. The inversion-b ased approach requires that unique (global) values of atomic parameters mu st represent very well spectral line profiles originating from very differ ent solar atmospheres within an observed field of view. To test this so-ca lled global method\, we analyzed synthetic spectra computed from magneto-h ydrodynamic models of the solar atmosphere and compared the results to the previously used methods. The method is general enough to be applied to th e spectral lines from the NUV to the infrared wavelengths. The global meth od is able to retrieve reliable estimates of atomic parameters even for we ak and blended spectral lines\, thus extending the list of spectral lines with reliable atomic parameters used to analyze solar and stellar spectra. \n\nhttps://meetings.aip.de/event/24/contributions/348/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/348/ END:VEVENT BEGIN:VEVENT SUMMARY:Classification Scheme for High-resolution Spectra Using Machine Le arning Algorithms DTSTART;VALUE=DATE-TIME:20230512T074000Z DTEND;VALUE=DATE-TIME:20230512T075500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-349@meetings.aip.de DESCRIPTION:Speakers: Ekaterina Dineva (Katholieke Universiteit Leuven)\nC ontemporary solar physics deals with increasing volumes of high-dimensiona l data from observations and realistic theoretical models alike. Machine L earning (ML) is rapidly integrated into solar and heliophysics research\, facilitating dimensionality reduction\, visualization and analysis. We dev eloped a pipeline\, which employed carefully selected unsupervised ML algo rithms for classification and cluster analysis\, to extract information re garding the physical properties of the solar atmosphere contained in the l arge variety of spectral profiles. The pipeline is tested on the synthetic spectra of the Fe I $\\lambda\\\,7090.38$ Å photospheric absorption line \, computed with the CO$^5$BOLD radiation hydrodynamics code. This line is also part of the observing setup for the Fast Multi-line Universal Spectr ograph (FaMuLUS) camera system at the Vacuum Tower Telescope (VTT). CO$^5$ BOLD snapshot time-series serve as a simulation of high-resolution\, fast- cadence solar observations\, thus confronting the pipeline with the scenar io of dynamic solar feature evolution. This project aims to deliver a robu st classification scheme with minimal user interaction\, which also prepar es the spectral dataset for further analysis\, such as spectral inversions . Successful classification allows quick identification of structure and d ynamics in the region of interest\, as well as diagnostics of the ambient plasma based on spectra line parameters.\n\nhttps://meetings.aip.de/event/ 24/contributions/349/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/349/ END:VEVENT BEGIN:VEVENT SUMMARY:Evolution of magnetic fields and energy release processes during h omologous compact major blowout-eruption solar flares DTSTART;VALUE=DATE-TIME:20230510T081000Z DTEND;VALUE=DATE-TIME:20230510T082500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-334@meetings.aip.de DESCRIPTION:Speakers: Suraj Sahu (Physical Research Laboratory)\nIt is oft en observed that the Sun produces repetitive coronal mass ejections (CMEs) with similar morphological features originating from the same source regi on. This kind of CMEs is known as homologous CMEs and their occurrence is majorly controlled by the storage of free magnetic energy in the active re gion corona. The stored energy is catastrophically released during flares\ , accompanied by successful eruption of plasma materials\, to be observed as CMEs. Therefore\, it is important to study the homologous flare-CME eve nts in order to understand their association in terms of sustained energy build-up in the corona. In this study\, we select three homologous flare-C ME events of successively increasing flaring intensities (M2.0\, M2.6\, X1 .0) originated in NOAA AR 12017 during 2014 March 28-29. We analyze the de tailed evolution of the photospheric line-of-sight magnetogram from ≈1 d ay before the first event and encompassing all the three events. Our obser vations reveal significant phases of emergence and cancellation of magneti c flux in and around the flaring region\, which strongly supports the idea of ‘tether-cutting’ model as a plausible triggering mechanism of the eruptions. We also analyze the build-up and release of free magnetic energ y in the active region corona\, which temporally correlates with a prolong ed phase of magnetic flux emergence. The importance of this study lies in the investigation of the intrinsic coupling of magnetic fields and associa ted processes from the photosphere to corona that resulted into the repeti tive build-up and eruption of magnetic flux ropes. Interestingly\, the hom ologous flux rope eruptions led to broad CMEs (angular width ≈100° to 3 60°)\, in spite of their origin from compact eruption-source site. We inv estigate this apparent observational paradox in the framework of generaliz ed ‘magnetic-arch blowout’ scenario\, which satisfactorily explains th e observed phenomena.\n\nhttps://meetings.aip.de/event/24/contributions/33 4/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/334/ END:VEVENT BEGIN:VEVENT SUMMARY:The magnetic complexity of solar active regions: insight on the CM E-flare relationship in Solar Cycle 24 DTSTART;VALUE=DATE-TIME:20230510T075500Z DTEND;VALUE=DATE-TIME:20230510T081000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-326@meetings.aip.de DESCRIPTION:Speakers: Luca Giovannelli (University of Rome Tor Vergata)\nS olar flares originate from active regions (ARs) hosting complex and strong bipolar magnetic fluxes. Forecasting the probability of an AR to flare an d defining reliable precursors of intense flares\, i.e.\, X- or M-class fl ares\, are extremely challenging tasks in the space weather field.\n\nIn t his work\, we focus on two metrics as flare precursors\, the unsigned flux R* and the novel topological parameter D\, representing the complexity of a solar active region. Both metrics are based on the automatic recognitio n of magnetic polarity inversion lines (PILs) in identified SDO/HMI ARs. W e use both a heuristic approach and a supervised machine-learning method t o validate the effectiveness of these metrics to predict the occurrence of X- or M-class flares in a given solar AR during the following 24 hr perio d. Moreover\, we revise the statistics of CME-flare relationship on Solar Cycle 24 using the GOES database and a CME database recently released\, de veloped using the Drag-Based Model (DBM) to assess the quality of such a d atabase. In particular\, we exploit the R* and D parameters to classify fl aring regions in different classes\, studying the CME-flare relationship f or those classes over Solar Cycle 24.\n\nhttps://meetings.aip.de/event/24/ contributions/326/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/326/ END:VEVENT BEGIN:VEVENT SUMMARY:Study of the evolution of magnetic energy and helicity injection i n an active region with recurring eruptive events DTSTART;VALUE=DATE-TIME:20230509T081500Z DTEND;VALUE=DATE-TIME:20230509T083000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-319@meetings.aip.de DESCRIPTION:Speakers: Marcelo López Fuentes (Instituto de Astronomía y F ísica del Espacio (CONICET-UBA))\nSolar events such as flares and coronal mass ejections are the most energetic phenomena affecting interplanetary space in timescales ranging from minutes to a few days. There has been\, i n recent years\, a strong interest in characterizing the processes that in ject magnetic energy and helicity in solar active regions (ARs) and the me chanisms that destabilize their magnetic structure leading to the energy r eleased during those events. We analyze the magnetic evolution of AR NOAA 11476 that produced a series of minifilament confined eruptions of the “ surge” type accompanied by M-class flares. In a previous work\, we found that these events are associated to the presence of a small rotating bipo le that emerged in the middle of the globally bipolar AR magnetic configur ation. The bipole rotation preceded and concurred in time with the observe d ejections. Magnetic flux cancellation is also identified along the polar ity inversion line of the bipole where the minifilaments were recurrently formed and ejected. Here we combine the analysis\, for the full AR and the rotating bipole\, of the evolution of a series of magnetic parameters com puted from SDO/HMI vector magnetograms with estimations of the magnetic en ergy and magnetic helicity injection obtained using the Differential Affin e Velocity Estimator for Vector Magnetograms (DAVE4VM) method. This proced ure is based on the determination\, from vector magnetograms\, of the affi ne velocity field constrained by the induction equation. Our results provi de a series of relations between the studied parameters that define proxie s of the magnetic evolution of the AR that\, eventually\, can be used as p ossible precursors of active events.\n\nhttps://meetings.aip.de/event/24/c ontributions/319/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/319/ END:VEVENT BEGIN:VEVENT SUMMARY:Chromospheric horizontal propagating waves revealed by fast cadenc e imaging in Ca II K with DKIST’s Visible Broadband Imager DTSTART;VALUE=DATE-TIME:20230509T073000Z DTEND;VALUE=DATE-TIME:20230509T074500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-316@meetings.aip.de DESCRIPTION:Speakers: Catherine Fischer (National Solar Observatory)\nThe Daniel K. Inouye Solar Telescope is currently acquiring first science data as part of its Operations Commissioning Phase. High-resolution\, fast-cad ence imaging in the chromospheric Ca II K filter of the Visible Broadband Imager reveals signatures of bright arches emanating radially from the loc ations of G-band bright points. The G-band bright points denote small-scal e magnetic elements harboring strong magnetic fields (~kGauss). Comparison with 3-D simulations suggest that the traveling bright arches are acousti c waves or shock fronts\, triggered by the movements of magnetic elements. Inspecting several examples of the events we indeed see the photospheric bright points changing their appearance and position\, indicating either a horizontal movement\, perhaps swaying\, or rotation and seem to be the so urce location for the bright arches.\n\nhttps://meetings.aip.de/event/24/c ontributions/316/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/316/ END:VEVENT BEGIN:VEVENT SUMMARY:Coronal voids and their magnetic nature DTSTART;VALUE=DATE-TIME:20230509T080000Z DTEND;VALUE=DATE-TIME:20230509T081500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-311@meetings.aip.de DESCRIPTION:Speakers: Jonathan David Nölke (Max Planck Institute for Sola r System Research)\nExtreme ultraviolet (EUV) observations of the quiet su n corona have revealed extended regions of reduced emission. These coronal voids are on average around 30% less intense than the quiet Sun and can h ave sizes corresponding to several supergranular cells. At least the large r of these voids can exist for many hours with their boundaries to the qui et Sun remaining more or less unchanged. The aim of our study is to unders tand what causes the reduced emission through an investigation of the unde rlying magnetic features in the photopshere. \n\nAt least two scenarios co uld explain why the voids appear dark: \n(1) The coronal voids could be ma gnetic structures that are (locally) open similar to coronal holes and app ear dark for the same reason as those do. (2) they could also be areas of lower (magnetic) heating due to lower magnetic field strength in the photo sphere below\, when compared to the typical quiet Sun.\n\nTo distinguish b etween the two scenarios\, we combine quiet Sun data from the high-resolut ion EUV-channel at 17.4 nm of the Extreme Ultraviolet Imager (EUI)\, showi ng coronal plasma close to 1 MK\, and magnetograms obtained with the high- resolution telescope of the Polarimetric and Helioseismic Imager (PHI)\, b oth onboard Solar Orbiter. \n\nOur results show the average unsigned magne tic field inside the voids to be reduced by $\\sim$ 25% with respect to th e entire observed quiet Sun region. Specifically\, there is little or no n etwork structure visible inside the coronal voids. Observed flux imbalance s are within the range of flux imbalances found in quiet Sun areas of simi lar size. Hence\, the flux imbalances we find in the voids are not signifi cant. Consequently\, it is highly unlikely that these voids are true minia ture versions of coronal holes.\nInstead\, we find that in general the uns igned magnetic flux in the photosphere below the voids is significantly sm aller than in the quiet Sun\, and the vast majority of stronger magnetic p atches is located outside the voids. The weaker photospheric field below t he voids will produce a Poynting flux smaller than in the surrounding quie t Sun. Consequently\, the coronal part above will be heated less and the v oids will appear darker in coronal emission.\n\nWe started a subsequent st udy into the temporal evolution of coronal voids on time scales from hours to several days. Our initial results for a time scale of a few hours indi cate that at least larger structures persist\, and their outer boundaries remain mostly unchanged during this time.\n\nhttps://meetings.aip.de/event /24/contributions/311/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/311/ END:VEVENT BEGIN:VEVENT SUMMARY:Non-LTE formation of the widely-used Fe I 6173 Å line DTSTART;VALUE=DATE-TIME:20230509T074500Z DTEND;VALUE=DATE-TIME:20230509T080000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-309@meetings.aip.de DESCRIPTION:Speakers: Smitha Narayanamurthy (Max Planck Institute for Sola r System Research)\nThe Fe I 6173 Å line is widely used to observe the so lar photosphere by many instruments. This includes the Helioseismic and Ma gnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) and the Polarimetric and Helioseismic Imager on board the Solar Orbiter. During an alysis\, this line is often assumed to have formed in Local Thermodynamic Equilibrium (LTE) conditions. However\, the UV overionization effects acti ng on the iron species has a strong influence on the Fe I abundance\, whic h affects the strength of this line\, resulting in departures from LTE. By synthesizing the Stokes profiles from snapshot of a three-dimensional mag netohydrodynamic simulation of the solar photosphere\, we have carried out a detailed investigation on the nature and strength of the non-LTE (NLTE) effects. We find that both intensity and polarization profiles can be str ongly affected by the NLTE effects\, and that these effects survive even w hen the profiles are averaged spatially or sampled on a coarse wavelength grid such as that used by the SDO/HMI and other magnetographs. Based on th e nature of departures from LTE\, treating the 6173 Å line in LTE will li kely result in an overestimation of temperature and an underestimation of the magnetic field strength.\n\nhttps://meetings.aip.de/event/24/contribut ions/309/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/309/ END:VEVENT BEGIN:VEVENT SUMMARY:Data Analysis Tools DTSTART;VALUE=DATE-TIME:20230512T071500Z DTEND;VALUE=DATE-TIME:20230512T074000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-409@meetings.aip.de DESCRIPTION:Speakers: Nazaret Bello Gonzalez (Leibniz-Institut für Sonne nphysik (KIS))\nhttps://meetings.aip.de/event/24/contributions/409/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/409/ END:VEVENT BEGIN:VEVENT SUMMARY:Machine Learning methods for solar spectroscopy and imaging DTSTART;VALUE=DATE-TIME:20230512T081000Z DTEND;VALUE=DATE-TIME:20230512T083500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-354@meetings.aip.de DESCRIPTION:Speakers: Andrés Asensio Ramos (Instituto de Astrofísica de Canarias)\nSolar spectropolarimetry is entering the realm of big data. Cur rent and future telescopes will produce data at a rate that will make it h ard to store in a single machine and even harder to operate on the data. T hankfully\, in the last decade\, machine learning has experienced an enorm ous advance\, thanks to the open possibility of training very deep and com plex neural networks. In this \ncontribution I show options to explore to deal with the big data problem and also how deep learning can be used to e fficiently solve difficult problems in Solar Physics. I will focus on how differentiable programming (aka deep learning) is helping us to have acces s to velocity fields in the solar atmosphere\, correct for the atmospheric degradation of spectropolarimetric data and carry out fast 3D inversions of the Stokes parameters to get physical information of the solar atmosphe re.\n\nhttps://meetings.aip.de/event/24/contributions/354/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/354/ END:VEVENT BEGIN:VEVENT SUMMARY:Recent Progress in Understanding Solar Flare Magnetism using Data- Driven Simulations and Statistical Analysis of Vector Magnetic Fields DTSTART;VALUE=DATE-TIME:20230510T073000Z DTEND;VALUE=DATE-TIME:20230510T075500Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-361@meetings.aip.de DESCRIPTION:Speakers: Maria Kazachenko (University of Colorado - Boulder / National Solar Observatory)\n​Continuous vector magnetic-field measurem ents by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynam ics Observatory (SDO) allowed us to run data-driven simulations of solar eruptions and perform statistical studies of magnetic-fields for many flar es. In this talk I will review new aspects of flare magnetism discovered u sing SDO data\, including progress in data-driven simulations and statisti cal studies of magnetic-reconnection fluxes\, their rates\, magnetic fluxe s of flare dimmings\, and magnetic-field changes during flares. I will sum marize how these results\, along with statistical studies of coronal mass ejections (CMEs)\, have improved our understanding of flares and the flare /CME feedback relationship. Finally\, I will highlight future directions t o improve the current state of understanding of solar-flare magnetism usin g observations and simulations.\n\nhttps://meetings.aip.de/event/24/contri butions/361/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/361/ END:VEVENT BEGIN:VEVENT SUMMARY:Photospheric MHD simulations: From sub-granular scales to active r egions DTSTART;VALUE=DATE-TIME:20230509T070000Z DTEND;VALUE=DATE-TIME:20230509T073000Z DTSTAMP;VALUE=DATE-TIME:20240704T115501Z UID:indico-contribution-24-362@meetings.aip.de DESCRIPTION:Speakers: Matthias Rempel (High Altitude Observatory\, Nationa l Center for Atmospheric Research)\nMore than 20 years ago most photospher ic MHD simulations focused primarily on small patches of granulation with moderate numerical resolution. Over the past 2 decades advances in computi ng infrastructure have enabled photospheric MHD simulations to cover most magnetic environments from quiet Sun to active Sun. In this talk I review these recent developments and focus primarily on simulations that cover th e extreme ends of the spectrum: (1) Small-scale dynamo simulations of quie t Sun magnetism and (2) Simulations of active region scales. (1) Recent re search (observations and modeling) supports the view that the origin of sm all-scale magnetism is mostly due to a small-scale dynamo that operates in dependently from the large-scale dynamo responsible for the solar cycle. R ecent simulations have shown that the saturation field strength and struct ure of the resulting magnetic field in the photosphere depend critically o n the contributions from deep and shallow recirculation within the strongl y stratified convection zone. Therefore\, the small-scale dynamo is not re stricted to the photosphere and involves a wide range of scales. Recent re search suggests that small-scale magnetic fields may play a critical role for convection zone dynamics. Outstanding questions concern the role of th e magnetic Prandtl number\, which will require in the future simulations w ith better resolution (\n\nhttps://meetings.aip.de/event/24/contributions/ 362/ LOCATION:Haus H\, Telegrafenberg URL:https://meetings.aip.de/event/24/contributions/362/ END:VEVENT END:VCALENDAR