Received: 28 Nov 2019 – Discussion started: 03 Feb 2020
Abstract. Implementing a nonlinear whole atmosphere gravity wave (GW) parameterization into the Middle and Upper Atmosphere Model extending to the lower thermosphere (160 km), we study the response of the atmosphere in terms of the circulation patterns, temperature distribution, and migrating terdiurnal solar tide activity to the upward propagating small-scale internal GWs originating in the lower atmosphere. We perform three test simulations for the Northern Hemisphere winter conditions in order to assess the effects of variations in the initial GW spectrum on the dynamics of the mesosphere and lower thermosphere. We find that the overall strength of the source level momentum flux has a comparatively small impact on zonal mean dynamics. The tails of the GW source level spectrum, however, are crucial for the lower thermosphere dynamics. With respect to the terdiurnal tide, we find a strong dependence of tidal amplitude on the induced GW drag, generally being larger when GW drag is increased.
This preprint has been withdrawn.
How to cite. Lilienthal, F., Yiğit, E., Samtleben, N., and Jacobi, C.: Interaction of Small-Scale Gravity Waves with the Terdiurnal Solar
Tide in the Mesosphere and Lower Thermosphere, Geosci. Model Dev. Discuss. [preprint], https://doi.org/10.5194/gmd-2019-339, 2020.
Gravity waves are a small-scale but prominent dynamical feature in the Earth's atmosphere. Here, we use a mechanistic nonlinear general circulation model and implement a modern whole atmosphere gravity wave parameterization. We study the response of the atmosphere on several phase speed spectra. We find a large influence of fast travelling waves on the background dynamics in the thermosphere and also a strong dependence of the amplitude of the terdiurnal solar tide, indicating wave interactions.
Gravity waves are a small-scale but prominent dynamical feature in the Earth's atmosphere. Here,...