Effects of Non Isothermality and Wind-Shears on the Propagation of Gravity Waves (I): Comparison between Hines Model and WKB Approach
In the presence of the vertical temperature & wind-speed gradients, we extend Hines’ isothermal and shear-free model to calculate the vertical wavenumber (mr) and growth rate (mi) of gravity waves propagating in a stratified, non-isothermal, and wind-shear atmosphere. The profiles obtained from the extended Hines’ model are compared with those from the Wentzel-Kramers-Brillouin (WKB) approach up to 300 km altitude. The empirical neutral atmospheric and wind models (NRLMSISE-00 and HWM93) are used to obtain the vertical profiles of the mean-field properties and the zonal/meridional winds.