Dynamics of coronal structures - Magnetic field-related heating and loop energy balance

Abstract

The heating of the inhomogeneous solar corona is discussed, based upon local coronal magnetic field energy release and associated plasma heating. Generally applicable expressions relating the parameters characterizing heated and confined atmospheres to heating processes involving magnetic field reconnection are derived; these are then evaluated for a specific heating process (involving nonlinear tearing-mode reconnection within topologically closed coronal structures). This work represents an extension and refinement of previous models of heating of confined coronal plasma structures by Rosner et al. We develop the theory for steady energy release and derive scaling laws for the average coronal loop temperature and energy-release rate which are compared with similar (but parameter-free) scaling laws derived by Rosner, Tucker, and Vaiana; this comparision allows us to determine the plasma b and ''nonpotential'' magnetic field within coronal loop structures in the context of the model. We also develop some constaints on the applicability of static coronal loop atmosphere models and show (by the use of numerical simulations) the close correlation between the thermal conductive loss and radiative loss for quasi-static confined loop atmospheres.