Middle atmosphere effects of localized gravity wave forcing

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The project involves a study of the middle atmosphere effects of localized internal gravity wave (IGW) forcing. Characteristics of the higher IGW activity regions, their spatial and temporal variability and links to other climate factors will be studied using GPS radio occultations. We will implement algorithms for full 3D diagnostics of the wave forcing and Brewer-Dobson circulation (BDC). The diagnostics will be applied along with numerical simulations of a mechanistic circulation model and reanalysis data in order to specify the BDC longitudinal variability and the role of the localized IGW forcing. In the next step, we will study the generation and propagation directions of planetary waves forced by the localized IGW forcing. Implications for the polar regions (circulation perturbations, winter preconditioning, sudden stratospheric warming characteristics), equatorial stratosphere (tropopause folds links, influence on the exchange with the troposphere) and mesosphere will be studied using the numerical simulations. The results will be evaluated in the context of the global middle atmospheric mean circulation and its variability.