arXiv subjects

Marianna B. Korsós

Publications and source records attributed to Marianna B. Korsós.

3 recordsLinked to original sources

arXiv2026

Brightenings AnD Polarity Inversion Tracking (BADPIT) method for studying solar active region evolution before major solar flares

This study investigates the relationship between extreme ultraviolet (EUV) transient brightenings (TBs) and the onset of GOES X-class solar flares in active regions (ARs). We introduce the Brightenings AnD Polarity Inversion Tracking (BADPIT) method that detects TBs across multiple SDO/AIA channels. To identify TBs, we impose two independent thresholds: a 3-(sigma) intensity-based criterion and a power-law divergence approach. We apply the BADPIT method to datasets of a flaring and a non-flaring AR for 24 hours as a pathfinder to a comprehensive statistical study for a complete performance verification: the flare-productive AR 11429 and the quiescent AR 13186, both sharing a similar Hale sunspot classification. Preliminary results are encouraging: significantly more TBs are detected in the flaring AR, with up to five times more 3-(sigma) thresholded TBs, while power-law thresholded events were frequent only in the flaring AR and mostly absent in the non-flaring AR. We find that both the power-law threshold method and the 3-(sigma) method can be useful diagnostic tools for distinguishing between imminent flaring or not, several hours before the onset of major solar flares.

astro-ph.SR↗

arXiv2026

Chromospheric magnetic field extrapolations reveal the flux-rope configuration of a solar filament

Solar eruptions are powered by the release of magnetic energy stored in the lower solar atmosphere, but the pre-eruptive magnetic configuration of filament channels remains difficult to determine. A central question is whether this energy is stored in a pre-existing magnetic flux rope or in a sheared arcade that forms a flux rope only during eruption. Resolving this ambiguity is critical for identifying instability thresholds and eruption triggers, yet photosphere-based extrapolations often provide insufficient constraints on the three-dimensional coronal field. Here, we introduce a data-driven magnetic field extrapolation framework that combines photospheric and chromospheric vector magnetograms in a unified multi-height optimization, while accounting for variable chromospheric formation heights and the 180° azimuthal ambiguity. Tests with radiative magnetohydrodynamic simulations show that photosphere-only extrapolations can misidentify the pre-eruptive magnetic configuration, whereas chromospheric vector constraints recover the three-dimensional structure substantially more accurately. Applied to multi-line spectropolarimetric observations of an active region filament obtained with the Swedish Solar Telescope, the method reveals a reconstructed magnetic field consistent with a pre-eruptive flux-rope configuration. These results show that chromospheric vector magnetic measurements can provide decisive constraints on filament magnetic configuration and open a path toward diagnosing magnetic-energy storage and instability in eruptive solar active regions.

astro-ph.SR↗

arXiv2024

Case studies on pre-eruptive X-class flares using R-value in the lower solar atmosphere

The R-value is a measure of the strength of photospheric magnetic Polarity Inversion Lines (PILs) in Active Regions (ARs). This work investigates the possibility of a relation between R-value variations and the occurrence of X-class flares in ARs, not in the solar photosphere, as usual, but above it in regions, closer to where flares occur. The modus operandi is to extrapolate the Solar Dynamic Observatory's (SDO) Helioseismic and Magnetic Imager (HMI) magnetogram data up to a height of 3.24 Mm above the photosphere and then compute the R-value based on the extrapolated magnetic field. Recent studies have shown that certain flare-predictive parameters such as the horizontal gradient of the vertical magnetic field and magnetic helicity may improve flare prediction lead times significantly if studied at a specific height range above the photosphere, called the Optimal Height Range (OHR). Here we define the OHR as a collection of heights where a sudden but sustained increase in R-value is found. For the eight case studies discussed in this paper, our results indicate that it is possible for OHRs to exist in the low solar atmosphere (between 0.36 - 3.24 Mm), where R-value spikes occur 48-68 hrs before the first X-class flare of an emerging AR. The temporal evolution of R-value before the first X-class flare for an emerging AR is also found to be distinct from that of non-flaring ARs. For X-class flares associated with non-emerging ARs, an OHR could not be found.

astro-ph.SR↗