Coupling of Magnetohydrodynamic Waves in Stratified Media

The theory presented deals with propagation of magnetohydrodynamic waves in a plasma whose propagation characteristics vary along the path of propagation. Plane waves with wave normals in the direction of the gradient of the medium are assumed. Modified Alfv\'en waves and acoustic waves obey a set of coupled wave equations. Alfv\'en waves are decoupled by a restricting assumption on the variation of the static magnetic field. The main aim of the paper is to demonstrate the generation of fairly intense acoustic waves in propagation of modified Alfv\'en waves in a steep gradient of the propagation conditions. This effect is investigated at a boundary which is equivalent to a very steep gradient.