Localising and Mapping the Most Eruptive Regions on the Sun

Marianna Korsos

Hosted by University of Sheffield, SP2RC - SSL, UK on October 16, 2025

Abstract

Active regions with increasing magnetic complexity are more likely to trigger major solar eruptions. During a single solar cycle, approximately 1000 active regions emerge on the Sun. Among these, about 250 develop magnetically complex configurations, but only ~10% of them go on to produce major eruptive events.

This presentation addresses the challenge of bridging short- and medium-term analyses of solar magnetic field evolution to improve our ability to identify which of these complex active regions are most likely to erupt. Specifically, we focus on how the location and magnetic evolution of these regions can help us isolate the small fraction (~10%) of magnetically complex active regions that eventually produce major eruptions.

The analysis of the longitudinal distribution of these eruptive active regions carried out builds on the concept of active longitudes, as introduced in Kornél Császár’s earlier ESPOS talk in this semester. In the second part of the talk, we present studies of the magnetic field evolution in the lower solar atmosphere for selected magnetically complex active regions that emerged within the identified active longitude band. Using approximately ten magnetic proxy parameters, we examine how the evolution of their structure provides insight into their eruptive potential.