Formation, structure, and stability of MHD intermediate shocks

Abstract

Contrary to the usual belief that MHD intermediate shocks are extraneous, we have recently shown by numerical solutions of dissipative MHD equations that intermediate shocks are admissible and can be formed through nonlinear wave steepening from continuous waves. In this paper, the formation, structure and stability of intermediate shocks in dissipative MHD are considered in detail. The differences between the conventional theory and ours are pointed out and clarified. We show that all four types of intermediate shocks can be formed from smooth waves. We also show that there are free parameters in the structure of the intermediate shocks, and that these parameters are related to the shock stability. In addition, we show that a rotational discontinuity can not exist with finite width, indicate how this is related to the existence of time‐dependent intermediate shocks, and show why the conventional theory is not a good approximation to dissipative MHD solutions whenever there is rotation in magnetic field.