Heating of the Magnetically Confined Corona Driven by Footpoint Shuffling: Theory and Observational Signatures

Abstract:

Coronal loops threaded by a strong axial magnetic field, with its footpoints shuffled by photospheric motions, develop magnetically dominated turbulent dynamics where energy cascades from large to small scales, forming strong current sheets that can account for a large fraction of the observed heating. The conditions for the formation of current sheets will be briefly examined. Nevertheless such current sheets and the associated magnetic reconnection cannot be observed directly, since the predicted spatial scale at which magnetic energy is released as thermal energy in nanoflares is well below the resolution limits of present instrumentation for observing the corona. Therefore in order to constrain this model, advance our understanding of
coronal heating and correctly interpret observations it is necessary to produce simulated "observables" that can be compared with observations. The propertied of the radiative emission computed from fully compressible simulations, and the observational implications of the topology developed by the turbulent magnetic field will be discussed.