Energy Release in a Turbulent Corona

Abstract

Numerical simulations of a two-dimensional section of a coronal loop subject to random magnetic forcing are presented. The forcing models the link between photospheric motions and energy injection in the corona. The results show the highly intermittent spatial distribution of current concentrations generated by the coupling between internal dynamics and external forcing. The total power dissipation is a rapidly varying function of time, with sizable jumps even at low Reynolds numbers, and is caused by the superposition of magnetic dissipation in a number of localized current sheets. Both spatial and temporal intermittency increase with the Reynolds number, suggesting that the turbulent nature of the corona can physically motivate statistical theories of solar activity.