Magnetic field topology from non-force free extrapolation and magnetohydrodynamic simulation of its eventual dynamics

TL;DR

This paper combines non-force-free magnetic field extrapolation with MHD simulations to analyze magnetic topology and its role in solar flare initiation, revealing the significance of quasi-separatrix layers in active region NOAA 11158.

Contribution

It introduces a novel approach using non-force-free extrapolation combined with MHD simulations to study magnetic topology and reconnection in solar active regions.

Findings

QSLs are detected in extrapolated magnetic fields.

QSLs are associated with flare onsets in NOAA 11158.

Non-force-free extrapolation captures more realistic magnetic structures.

Abstract

Magnetic reconnections (MRs) for various magnetic field line (MFL) topologies are believed to be the initiators of various solar eruptive events like flares and coronal mass ejections (CMEs). Consequently, important is a thorough understanding and quantification of the MFL topology and their evolution which leads to MRs. Contemporary standard is to extrapolate the coronal MFLs using equilibrium models where the Lorentz force on the coronal plasma is zero everywhere, because either there is no current or the current is parallel to the magnetic field. In tandem, a non-force-free-field (NFFF) extrapolation scheme has evolved and allows for a Lorentz force which is non-zero only at the photosphere but asymptotically vanishes with height. The paper reports magnetohydrodynamic (MHD)- simulations initiated by NFFF extrapolation of the coronal MFLs for the active region NOAA 11158. Interestingly, quasi-separatrix layers (QSLs) which facilitate MRs are detected in the extrapolated MFLs. The AR 11158 is flare producing and, the paper makes an attempt to asses the role of QSLs in the flare onsets.