The propagation of groups of internal gravity waves in a shear flow

摘要: The propagation in a shear flow of travelling internal gravity waves short wavelength is investigated by the W.K.B. approximation. This implies that Richardson number large. It shown wave group moves with local velocity defined terms dominant wavenumber, absolute frequency and horizontal components wavenumber being constant. energy carried packet varies, proportional to relative frame moving mean wind. A packet, on this approximation, can never pass through critical level at which its phase equal wind, nor it reflected there. These results imply restrictions from troposphere upper atmosphere.