Study of the evolution of magnetic energy and helicity injection in an active region with recurring eruptive events

LÓPEZ FUENTES, M.C.; POISSON, M.; MANDRINI, C.H.

Postdam

Conferencia; SOLARNET Conference: The Many Scales of the Magnetic Sun; 2023

Solar events such as flares and coronal mass ejections are the most energetic phenomenaaffecting interplanetary space in timescales ranging from minutes to a few days. There has been,in recent years, a strong interest in characterizing the processes that inject magnetic energy andhelicity in solar active regions (ARs) and the mechanisms that destabilize their magnetic structureleading to the energy released during those events. We analyze the magnetic evolution of ARNOAA 11476 that produced a series of minifilament confined eruptions of the “surge” typeaccompanied by M-class flares. In a previous work, we found that these events are associated tothe presence of a small rotating bipole that emerged in the middle of the globally bipolar ARmagnetic configuration. The bipole rotation preceded and concurred in time with the observedejections. Magnetic flux cancellation is also identified along the polarity inversion line of the bipolewhere the minifilaments were recurrently formed and ejected. Here we combine the analysis, forthe full AR and the rotating bipole, of the evolution of a series of magnetic parameters computedfrom SDO/HMI vector magnetograms with estimations of the magnetic energy and magnetichelicity injection obtained using the Differential Affine Velocity Estimator for Vector Magnetograms(DAVE4VM) method. This procedure is based on the determination, from vector magnetograms, ofthe affine velocity field constrained by the induction equation. Our results provide a series ofrelations between the studied parameters that define proxies of the magnetic evolution of the ARthat, eventually, can be used as possible precursors of active events.