The Triggering of the 29-March-2014 Filament Eruption

TL;DR

This study investigates the magnetic field configurations leading to a solar filament eruption on March 29, 2014, combining observational data and nonlinear force-free field extrapolations to understand the eruption mechanism.

Contribution

It identifies two flux ropes in the active region and explains why only one erupts, highlighting the role of tether cutting reconnection in triggering the eruption.

Findings

Two flux ropes were present before the flare.

Only one flux rope erupted during the flare.

Tether cutting reconnection facilitated the eruption.

Abstract

The X1 flare and associated filament eruption occurring in NOAA Active Region 12017 on SOL2014-03-29 has been the source of intense study. In this work, we analyse the results of a series of non linear force free field extrapolations of the pre and post flare period of the flare. In combination with observational data provided by the IRIS, Hinode and SDO missions, we have confirmed the existence of two flux ropes present within the active region prior to flaring. Of these two flux ropes, we find that intriguingly only one erupts during the X1 flare. We propose that the reason for this is due to tether cutting reconnection allowing one of the flux ropes to rise to a torus unstable region prior to flaring, thus allowing it to erupt during the subsequent flare.