Propagation of perturbations in a gravity-stratified atmosphere with a steep density gradient

We have investigated the propagation of perturbations in a gravity-stratified atmosphere without making the adiabatic assumption and we have obtained rather different results from those under the adiabatic assumption, in particular, the height at which the perturbation becomes a shock wave was found to be much lower. Our results lead to the view that the heating of the corona and chromosphere may be caused by perturbations starting at various heights above the photosphere, rather than wholly by accoustic and MHD waves originating in the convective zone below the photosphere.