Self-consistent nanoflare heating in model active regions: MHD avalanches

Abstract

ABSTRACT Straightened cylindrical models of coronal loops have been standard for decades, and shown to support nanoflare-like heating, but the influence of geometric curvature in models upon the heating produced has not been discussed in depth. Heating, its spatiotemporal distributions, and the associated mechanisms responsible are discussed, and compared with those from straightened models of a coronal loop. Previously, magnetohydrodynamic avalanches have been generalized to curved loops, and shown to be viable. From that study, the associated heating is analysed and discussed in depth. Heating is seen to arise from processes originally instigated, yet not dominated, by magnetic reconnection, producing bursty, aperiodic nanoflares, dispersed evenly throughout the corona, but with a modest bias away from footpoints. One novelty arising is the simultaneous yet independent occurrence of nanoflare-like events at disjoint sites along individual strands, anticipating some features recently seen in ‘campfires’ by Solar Orbiter. With a view to future refinements in the model and to the inclusion of additional physical effects, the implications of this analysis are discussed.