Global and local dynamics of X-flare-producing active regions during solar cycle 25 peak phase

¹ High Altitude Observatory, NSF-NCAR, 3080 Center Green Dr, Boulder, CO 80301, USA
² Department of Atmospheric Sciences, University of Sao Paulo, R. do Matão, 1226, Sao Paulo, 05508-090 SP, Brazil
³ National Solar Observatory, 3665 Discovery Dr, Boulder, CO 80303, USA
⁴ Hansen Experimental Physics Laboratory, 452 Lomita Mall, Stanford, CA 94305-4085, USA
⁵ Lynker Space, Lynker 5445 Conestoga Ct Ste 100, Boulder, CO 80301, USA

^⋆ Corresponding author; brenorfs@gmail.com

Received: 9 July 2024
Accepted: 21 August 2024

Abstract

Context. The configuration of the longitudinally elongated region that active regions (ARs) cluster around, known as a toroid belt, has been shown to be an indicator of intense activity. In particular, complex ARs at locations in the north and/or south toroids tend to appear “tipped-away” with respect to each other. On the other hand, magnetic helicity has been used as an indicator of flare activity in ARs.

Aims. As solar cycle (SC) 25 approaches its peak, a number of significant (X-class) flares have been produced. Here, we investigate the circumstances surrounding two of the most flare-prolific ARs of solar cycle 25, namely, ARs 13590 and 13514. Two aspects of the evolution of these ARs are investigated in this work: the global-scale magnetic toroid configuration and small-scale magnetic field morphology and topology – before, during, and after the onset of major flares.

Methods. We studied the global morphology of the solar magnetic fields near intense flares in terms of the spatial distribution of ARs on magnetic fields synoptic maps. On AR scales, we analyzed the magnetic helicity accumulation, as well as its current-carrying and potential components.

Results. Our results are consistent with major flare-prolific ARs from solar cycles 23 and 24. In particular, we observe a consistent dominance of current-carrying magnetic helicity at the time of major flares. The evolution of global magnetic toroids, indicating the occurrence of flare-prolific ARs in the tipped-away portion of the toroid, together with the local dynamics of complex ARs, could offer a few weeks of lead time to prepare for upcoming space weather hazards.