Guiding properties of a non-isothermal atmosphere for acoustic-gravity waves

The propagation of pressure waves in a stratified, non-isothermal atmosphere is studied in the linear approximation. It is found that acoustic and acoustic-gravity waves can be horizontally guided by the effect of the Earth's thermo cline alone, under very mild conditions on the temperature gradient steepness. The effect of the Earth's surface is also studied. Lamb's modes associated with the rigid surface are, then, identified and their behaviour, as a function of the Earth's position, is discussed. Finally, dissipation is included, and its effect is derived using a perturbation technique