Abstract
A theory of propagation of acoustic-gravity waves in a temperature- and wind-stratified atmosphere is developed. It is shown by using suitable wind structure in a COSPAR standard atmosphere that both the normal dispersion (group velocity increasing with period) and the inverse dispersion (group velocity decreasing as the period increases) of acoustic-gravity waves can be explained. It is found that winds of the order of 100 m sec−1 at about 100 km altitude are needed to account for inverse dispersion in the period range of about 5–15 min.