Analyzing the potential of eruptivity proxies to forecast the upcoming solar flares

Manu Gupta  University of Graz, Austria; Julia Thalmann - University of Graz, Austria; Astrid Veronig - University of Graz, Austria

Session: The solar sources of space weather

Abstract

Solar flares and coronal mass ejections erupting from the solar active regions can severely impact our space weather. Physics behind these highly energetic solar eruptions is still not well understood, and predicting them is one the key challenge today. Magnetic helicity induced from the underlying active region to magnetic loops in solar corona can cause reconnections and flare eruptions. Therefore, to have a better understanding of these eruptive events, we identify a number of active regions based on different flaring activity and evolutionary profiles. We then compute the coronal magnetic energy and helicity for those active regions, based on nonlinear force-free coronal magnetic field models with a high level of solenoidality, and study the evolution of these quantities around the time of flare. Furthermore, we estimate the preflare levels of the helicity ratio of current-carrying magnetic field to the total helicity and test the ability of this quantity to predict the flare eruptivity. We find that the value of helicity ratio can efficiently indicate the eruptive potential of an active region, and the order of helicity ratio is higher for the active regions with eruptive flares than the ones with confined flares.