Speaker
Description
First Name: Meetu
Last Name: Verma
Affiliation: Leibniz Institute for Astrophysics Potsdam (AIP)
All Authors: Meetu Verma
Abstract: The X9.0 flare on 3 October 2024 was the strongest of Solar Cycle 25. We analyze the pre-, during-, and post-flare evolution in active region NOAA 13842 using multi-wavelength spectra and imaging from Hinode/SP, SDO/HMI continuum and magnetograms, AIA 1600 Å images, IRIS slit-jaw and sit-and-stare data, and SHARP data products. Background-subtracted Solar Activity Maps (BaSAMs) from continuum, LOS magnetograms, and 1600 Å images track changes across the three intervals. Major upper-atmospheric changes (AIA 1600 Å and IRIS 1300 Å) occur in a complex sunspot where opposite-polarity umbrae converge along an extended polarity inversion line (PIL). A two-ribbon flare develops and leaves distinct post-flare signatures. Continuum BaSAMs show widespread pre- and post-flare changes but are restricted to the PIL during the flare. Magnetogram BaSAMs highlight the extended yet PIL-focused evolution and suggest magnetic connectivity between the sunspot and surrounding supergranules. Flow fields from local correlation tracking (LCT) for images and from DAVE/DAVE4VM for magnetograms, together with Hinode/SP data, quantify magnetic and flow restructuring. The t-distributed stochastic neighbor embedding (t-SNE) applied to Hinode Stokes-U profiles reveals changes in magnetic field structure along the PIL during the pre- and post-flare intervals.