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SUMMARY:Flare evaporation\, condensations\, and ribbons - Malcolm Druett (
 Sheffield)
DTSTART:20250317T140000Z
DTEND:20250317T150000Z
UID:TALK227668@talks.cam.ac.uk
CONTACT:Roger Dufresne
DESCRIPTION:Evaporation and condensation processes are highly dynamic in s
 olar flares\, and both can be investigated through the chromospheric spect
 ral lines and flare ribbons.\n\nEvaporation occurs from a source of chromo
 spheric flare ribbon material. The key mechanism(s) driving the evaporatio
 n are not neatly resolved\, with plausible candidates including non-therma
 l beams of particles\, field-aligned thermal conduction\, Alfven waves\, a
 nd reconnection outflow jets. We use state-of-the-art multi-dimensional MH
 D simulations to investigate differences in flare evolution that result fr
 om different energy transport mechanisms.\n\nCondensations are seen in pos
 t flare loop arcades\, with coronal rain events in which condensed materia
 l flows down towards the bright ribbons. We present the variations of flar
 e ribbon spectral profiles using high-resolution spectro-polarimetric SST 
 observations and sub-second cadence IRIS satellite spectra. These are used
  to track condensation flows and ribbon features. We also present so-calle
 d “chromospheric condensations” interpreting them through our multi-di
 mensional MHD models. We provide an updated schematic to interpret the for
 mation of flare ribbons from the spectra.\n\nOngoing developments of our s
 imulations are introduced (1) improving the lower atmosphere used\, and th
 e initial reconnection location (2) including asymmetry and more realistic
  chromospheric magnetic field parameters\, (3) beam particle energy budget
 s and spectra informed by reconnection and particle acceleration modelling
 . (4) building a framework to estimate radiative energy losses and gains i
 n the chromosphere from detailed 1D RADYN models.\n\nThis work was carried
  out in collaboration with Alex Pietrow\, Ioannis Kontogiannis\, Wenzhi Ru
 an\, Rony Keppens\, Foad Hanassi-Savari\, Maxime Dubart\, Fabio Bacchini
LOCATION:MR14 DAMTP and online
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