Stratospheric gravity waves in ICON

Compared to the troposphere, the midlatitude stratosphere may appear almost boring; it is statically stable i.e. instability processes are hardly known, and water vapour is present only in traces. Yet, a large body of evidence shows that stratospheric dynamics affect the surface weather within a few weeks, though exact mechanisms are poorly understood. The troposphere and stratosphere communicate through both Rossby and gravity waves. 

This master thesis proposal focuses on the propagation of resolved stratospheric gravity waves in ICON simulations. Recent research has shown that stratospheric gravity waves may be excited within the stratosphere due to the lateral shear of the horizontal wind within the polar vortex.
The student will compare gravity wave propagation in simulations initialised with and without tropospheric gravity wave sources and compare their vertical and horizontal propagation. The research question is the origin of gravity waves and the effect of the background flow on the wave propagation.

Supervisors: Claudia Stephan and Nedjeljka Zagar