Magnetic Configuration of Active Regions Associated with GLE Events

Charged particles, generated in solar flares, sometimes can attain extremely high energy, above the 500-MeV level, and produce abrupt ground-level enhancements (GLEs) on the ground-based detectors of cosmic rays. The initial flares are strong eruptions and they could originate from active regions (ARs). A list of GLE events and associated flares was initially available, and our aim was to find the hosting AR for each GLE event. Moreover, we aimed to classify the revealed ARs using the magnetomorphological classification (MMC: Abramenko, 2021). We have shown that in 94% of cases such ARs belong to the most complex morphological classes, namely, $\beta \gamma$ $\beta \gamma $ , $\beta \delta$ $\beta \delta $ , $\gamma \delta$ $\gamma \delta $ , $\beta \gamma \delta$ $\beta \gamma \delta $ classes by the Hale classification and B2, B3 classes by the MMC. We also found that the GLE-associated ARs are the ARs with the total unsigned magnetic flux much stronger than the common ARs of the same complexity. The set of GLE-related ARs only partially overlaps with the set of SARs (superactive regions). These ARs seem to be a manifestation of nonlinearities in the regular process of the global mean-field dynamo, the key ingredient to maintain fluctuations and to create critical conditions in different aspects of the solar activity.