Abstract Details

Name: Ranadeep Sarkar
Affiliation: Udaipur Solar Observatory, Physical Research Laboratory
Conference ID: ASI2020_505
Title : Lorentz Force Evolution Reveals the Energy Build-up Processes during Recurrent Eruptive Solar Flares
Authors and Co-Authors : Ranadeep Sarkar, Nandita Srivastava, and Astrid M. Veronig
Abstract Type : Poster
Abstract Category : Sun and the Solar System
Abstract : The energy release and build-up processes in the solar corona have significant implications in particular for the case of large recurrent flares in the same active region (AR), which pose challenging questions about the conditions that lead to the episodic energy release processes. It is not yet clear whether these events occur due to the continuous supply of free magnetic energy to the solar corona or because not all of the available free magnetic energy is released during a single major flaring event. In order to address this question, we report on the evolution of photospheric magnetic field and the associated net Lorentz force changes in ARs 11261 and 11283, each of which gave rise to recurrent eruptive M- and X-class flares. Our study reveals that after the abrupt downward changes during each flare, the net Lorentz force increases by (2–5)×10^22 dyne in between the successive flares. This distinct rebuild-up of net Lorentz forces is the first observational evidence found in the evolution of any nonpotential parameter of solar ARs, which suggests that new energy was supplied to the ARs in order to produce the recurrent large flares. The rebuild-up of magnetic free energy of the ARs is further confirmed by the observations of continuous shearing motion of moving magnetic features of opposite polarities near the polarity inversion line. The evolutionary pattern of the net Lorentz force changes reported in this study has significant implications, in particular, for the forecasting of recurrent large eruptive flares from the same AR and hence the chances of interaction between the associated CMEs.