CME-Sheath and Shock Heating by Surface Alfven Wave Dissipation in the Lower Corona

We use the new solar corona component of the Space Weather Modeling Framework (van der Holst et al. 2010), in which the Alfven wave energy evolution is coupled self-consistently to the magnetohydrodynamic equations, to study the evolution of a coronal mass ejection (CME) and the shock it drives in the lower corona (2-8Rs). In this solar wind model, the wave pressure gradient accelerates the wind, and wave dissipation heats the wind. Kolmogorov-like dissipation and surface Alfven wave damping are considered for the dissipation of the waves (Evans et al. 2011). We use a modified Titov-Demoulin flux rope to initiate an eruption, and include magnetogram data from CR2029 (May 2005) as a boundary condition for the coronal magnetic field. Synthetic white light images from the simulation are used to determine the lateral expansion. We show that the expansion of the flux rope leads to the concentration of wave energy at the shock and in the sheath region. The expansion also creates a piled-up compression (PUC) region of plasma density at the back of the sheath, strongest at the flanks of the CME. The wave energy concentrated at the shock and sheath is dissipated by surface Alfven wave damping due to the density gradients, which heats the sheath. We present analysis of the momentum exchange between the solar wind and the waves, and discuss the effect of wave dissipation on the CME evolution.