Wave Transience in a Compressible Atmosphere. Part III: The Saturation of Internal Gravity Waves in the Mesophere

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  • 1 Department of atmosphere Sciences, University of Washington, Seattle 98195
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Abstract

It is shown that the analytic transient internal gravity wave solutions derived by Dunkderton (1981a,b) remain qualitatively unchanged when a “saturation hypothesis” is included in the analysis. Furthermore, the wave flux in the saturated region is not constant in height, and experiences considerable falloff as the critical level is approached. Wave transience would appear to lower the level of wavebreaking on the order of a scale height.

It is also shown that these analytic solutions allow shock formation at the trailing edge of the wave packet, for both Boussinesq and atmospheric cases. An “equal-area” rule any be used to determine the position of both internal and trailing shocks. Saturation leads to a net mean flow change slightly different from that of the “nonsaturated” solutions.

Abstract

It is shown that the analytic transient internal gravity wave solutions derived by Dunkderton (1981a,b) remain qualitatively unchanged when a “saturation hypothesis” is included in the analysis. Furthermore, the wave flux in the saturated region is not constant in height, and experiences considerable falloff as the critical level is approached. Wave transience would appear to lower the level of wavebreaking on the order of a scale height.

It is also shown that these analytic solutions allow shock formation at the trailing edge of the wave packet, for both Boussinesq and atmospheric cases. An “equal-area” rule any be used to determine the position of both internal and trailing shocks. Saturation leads to a net mean flow change slightly different from that of the “nonsaturated” solutions.

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