Middle atmosphere effects of localized gravity wave forcing (MATELO)

DFG JA836/32-1 (2016-2018)

SHK gesucht
Student Assistant position available

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.

Cooperation partner: Department of Atmospheric Physics, Faculty of Mathematics and Physics, Charles University in Prague (Prof. P. Pišoft)

Brewer-Dobson circulation vectors for a GPS based longitudinal dependent run. Residual velocity has units m/s. The intensity of circulation grows from blue to red.

Publications related to the project:

Šácha, P., F. Lilienthal, Ch. Jacobi, and P. Pišoft, 2016: Influence of the spatial distribution of gravity wave activity on the middle atmospheric circulation and transport, Atmos. Chem. Phys., 16, 15755-15775, doi:10.5194/acp-16-15755-2016.

Šácha, P., A. Kuchar, Ch. Jacobi, and P. Pišoft, 2015: Enhanced internal gravity wave activity and breaking over the Northeastern Pacific / Eastern Asian region, Atmos. Chem. Phys., 15, 13097-13112, doi:10.5194/acp-15-13097-2015.

Šácha, P., P. Pišoft, F. Lilienthal, and Ch. Jacobi, 2015: Internal gravity wave activity hotspot and implications for the middle atmospheric dynamics. In: L. Ouwehand (Ed.), Proceedings of ATMOS 2015, 8.-12.6.2015, Heraklion, ESA SP-735, ISBN: 978-92-9221-299-5, id.16.

Lilienthal, F., P. Šácha, and Ch. Jacobi, 2015: Gravity wave effects on a modeled mean cir­cu­lation, Rep. Inst. Meteorol. Univ. Leipzig, 53, 11 - 22.

Last update 3 April 2017 by Ch. Jacobi