Acoustic and gravity waves in a weakly conductive atmosphere

Wave solutions are obtained to the system of equations of a compressible vertically stratified electrically conducting atmosphere performing small fluctuations about the state of rest. The solutions are obtained in a 'noninductive' linear approximation, since the induced magnetic field may be ignored, and only the current induced by an external magnetic field need be considered. Analysis of the solutions for magnetic Reynolds numbers much smaller than unity showed that acoustic and gravity waves exist, as in the lower atmosphere, but the dispersion relation is modified somewhat by the presence of additional terms accounting for the gyroscopic effect and 'anisotropic' friction