Study of magnetic field topology of active region 12192 using an extrapolated non-force-free magnetic field

TL;DR

This study investigates the magnetic field topology of active region 12192 before an X3.1 flare using a novel non-force-free field extrapolation, highlighting magnetic null points and QSLs as potential reconnection sites.

Contribution

It introduces a new non-force-free extrapolation method to analyze the coronal magnetic field, capturing Lorentz forces in the photosphere for better flare prediction.

Findings

Identification of magnetic null points and QSLs as reconnection sites

Correlation between magnetic topology features and flare occurrence

Enhanced understanding of magnetic reconnection processes in active regions

Abstract

The solar active region (AR) 12192 was one of the most flare productive region of solar cycle 24, which produced many X-class flares; the most energetic being an X3.1 flare on October 24, 2014 at 21:10 UT. Customarily, such events are believed to be triggered by magnetic reconnection in coronal magnetic fields. Here we use the vector magnetograms from solar photosphere, obtained from Heliospheric Magnetic Imager (HMI) to investigate the magnetic field topology prior to the X3.1 event, and ascertain the conditions that might have caused the flare. To infer the coronal magnetic field, a novel non-force-free field (NFFF) extrapolation technique of the photospheric field is used, which suitably mimics the Lorentz forces present in the photospheric plasma. We also highlight the presence of magnetic null points and quasi-separatrix layers (QSLs) in the magnetic field topology, which are preferred sites for magnetic reconnections and discuss the probable reconnection scenarios.