Kesava Ramachandran has successfully defended his Ph.D. Thesis

On Wednesday this week, our Ph.D. student Kesava Ramachandran has successfully defended his thesis at the University of Rostock. In his work he investigated mesospheric instabilities, which play an important role in understanding the energy budget of the atmosphere, using both, observations and direct numerical simulations. His thesis focused on the study of kilometer-scale instabilities with horizontal scales of less than 100 km in the mesosphere and lower thermosphere (MLT) region.

By means of airglow imagers, on a particular type of gravity wave event called a mesospheric bore was observed over Germany. The observation was complemented by two-dimensional Direct Numerical Simulation (DNS) of the Navier-Stokes equations under the Boussinesq approximation. In addition, the inclusion of the wind gradient alongside the thermal channel led to the generation of secondary instabilities previously reported in observations of both bores and solitary waves. The exisiting simulation could be extended to three dimensions, resulting in the conclusion that kilometer-scale dynamics are also affected by the generation of secondary instabilities in the direction transverse to the propagation direction.

In the picture: Prof. Dr. Jorge L. Chau, Prof. Dr. Claudia Stolle, Kesava Ramachandran, Prof. Dr. Sascha Kosleck, Prof. Dr. Sven Grundmann and Prof. Dr. Uwe Ritschel