Proton Flares in Solar Activity Complexes: Possible Origins and Consequences

Abstract

Solar flares observed during the 24th solar-activity cycle and accompanied by fluxes of particles detected at the Earth’s orbit with intensities exceeding 10 particles cm⁻² s⁻¹ and energies of more than 10 MeV per particle mainly occurred in activity complexes (82% of cases), with 80% of these occurring no more than 20 heliographic degrees from the nearest coronal holes. The correlation between the X-ray classes of flares and the proton fluxes detected at the Earth’s orbit is weak. The work presented here supports the hypothesis that the leakage of particles into the heliosphere is due to the existence of long-lived magnetic channels, which facilitate the transport of flare-accelerated particles into the boundary regions of open magnetic structures of coronal holes. The possible contribution of exchange reconnection in the formation of such channels and the role of exchange reconnection in the generation of flares are discussed.