Smoothing of MHD Shocks in Mode Conversion

Abstract

Shock waves are simulated passing through the Alfv\'en-acoustic equipartition layer in a stratified isothermal magneto-atmosphere. The recent ray-theoretic calculations of N\'u\~nez (2019) predicted smoothing of the shock through this layer, causing both the fast and slow components to emerge as continuous waves. However, it is found that the partial mode conversion expected from linear theory for oblique incidence of the shock on the magnetic field is accompanied by a smoothing of the slow-shock only, whilst the fast-shock persists. Explanations are presented based on MHD mode conversion and shock theory.