Numerical simulation of mesoscale structures in the northern Alpine foreland during front passages: A dry cold front with pre-frontal foehn

A three-dimensional numerical model is used to simulate the passage of a cold front with pre-frontal foehn over the northern Alpine foreland. A passive nesting scheme allows a detailed inspection of mesoscale patterns in southern Bavaria. The results are discussed with reference to observations taken during the German Front Experiment in 1987. The simulation reveals many mesoscale features which are very similar to those observed. It is shown that the local appearance of the frontal passage varies with the distance from the mountains. Finally, the simulated transport of passive scalars is discussed in order to explain the temporary reduction of ozone concentration on the rear side of the observed front.