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The vertical wavenumber (VWN) spectra of height profiles of winds over a tropical station of Gadanki (13.5 degrees N, 79.2 degrees E; obtained using Indian Mesosphere Stratosphere Troposphere radar) show distinct nature of VWN spectra, which do not match with the so-called universal wavenumber spectra. The universal wavenumber spectra have three distinct regions: unsaturated (having log-log slope of 2), saturated (having log-log slope of -3), and turbulence region (having log-log slope of -5/3). In present work, we report the presence of positive slope at the higher end of the VWN spectra indicating the presence of unsaturated gravity waves, a kind of which is not reported so far. Many negative slopes of the order of similar to-6, similar to-9, and similar to-12 are noticed at the end of the spectra beyond the turbulence region of the wavenumber spectra, which is also not reported in any previous studies up to now.

Plain Language Summary The amplitudes of atmospheric gravity wave (GW) increase exponentially throughout their propagation from lower to higher atmosphere. Therefore, these GWs impart energy to the surroundings, while their power of wavenumber spectra and spectral slope gets saturated to preserve overall stability. The universal wavenumber spectra have three distinct regions: unsaturated (having log-log slope of 2), saturated (having log-log slope of -3), and turbulence region (having log-log slope of -5/3). In present work, we report the presence of positive slope at the higher end of the vertical wavenumber spectra indicating the presence of unsaturated GWs, a kind of which is not reported so far. Many negative slopes of the order of similar to-6, similar to-9, and similar to-12 are noticed at the end of the spectra beyond the turbulence region of the wavenumber spectra, which is also not reported in any previous studies up to now.