Evolution of the daytime atmospheric boundary layer structure in deep Alpine valleys

Abstract

International audienceHigh-resolution numerical simulations using the ARPS (Advanced Regional Prediction System) model have been compared with collected data during a whole week of POVA field campaign in the Maurienne valley (France) during summer 2003. Wind profiler and tethered ballon were operated to investigate vertical flow structure of the atmosphere and its evolution. Both ground surface and upper-levels calculated winds show good agreement with the observations. Specific features such as wind reversal and mixed boundary layer up to approximately the altitude of the surrounding mountains were reproduced. The wind reversal was observed to be much more sudden than in the Chamonix valley (France)