Influence of vertical heterogeneity of the atmosphere temperature on the propagation of acoustic-gravity waves

Abstract

A new approach to the study of acoustic-gravity waves (AGW) in the Earth’s atmosphere in the presence of a vertical temperature inhomogeneity is proposed. Using this approach, the local AGW dispersion equation is obtained for an atmosphere with a small vertical temperature gradient. The modification of acoustic and gravitational regions of freely propagating AGWs on the spectral plane is studied depending on the temperature gradient. It is shown that, the acoustic and gravitational regions approach each other with a positive temperature gradient and the distance between them increases with a negative gradient. On the spectral plane, the dispersion curves of non-divergent and anelastic horizontal wave modes are the indicators of location of the acoustic and the gravitational regions of freely propagating AGWs. The possibility of overlapping the acoustic and the gravitational regions of AGWs in non-isothermal atmosphere is investigated.