Abstract Sabine Hittmeir, Universität Wien:
Multiscale asymptotics for the convective region of tropical squall lines
We analyse the convective region of tropical squall lines by introducing a setting of several columnar clouds with small horizontal diameter 1 km, which are embedded into a larger scale area 10 km. To resolve the dynamics in these hot tower regions we have to define an appropriate small scale coordinate, which allows for each cloud tower to have its own centerline. The nonlocality of the small scale fluctuations of the horizontal velocity and the pressure components requires moreover the introduction of an intermediate scale coordinate, at which the dynamics of the individual towers can be connected. Since the overall saturated area is small, new systematic averaging procedures have to be performed, which allow to represent the effects of the cloud dynamics on the larger scale flow. The onset regime with weak precipitation moreover requires a separate analysis on the short time scale. This work is joint work with Rupert Klein.