Spatial evolution of foehn flows in the Rhine Valley area: quantification using high resolution simulations

Abstract

The Rhine valley was one target area chosen during the Mesoscale Alpine Programme (MAP) field experiment to study Foehn flows. The dense data set available has allowed the computation and validation of high resolution simulations. This paper quantifies the distribution of the Foehn flow between the different valleys for different simulated cases. Mass fluxes are computed inside the valley at different stages of Foehn life time. The part played in the penetration of the Foehn to the ground by the presence of a cold air mass in the valley is highlighted. The computation of the potential temperature budget for one case shows that advection and turbulence are the two main physical processes involved in the evolution rate of potential temperature.