Transport de la neige par le vent sur un site de montagne : mesures et modélisation numérique à l'échelle du massif

Numerical experiments of wind transport over an instrumented site (medium and large scales)

Centre d'Etudes de la Neige, Météo-France

Abstract

For about ten winter seasons, the CEN and the CEMAGREF, two french laboratories involved in snow research, have performed intensive field measurement campaigns concerning various snow and weather parameters during blowing snow events. The observation sites are located near the Alpe d'Huez ski resort at elevations between 2700 and 2800 m (Col du Lac Blanc). The numerical simulation of such phenomena, in the framework of the operational avalanche hazard forecast, has also begun some years ago. The different numerical experiments presented here. have the benefit of all these archived data. They aim at representing the local wind and its effects on the distribution of snow and the associated avalanche hazard. The occurence of wind transport is already routinely evaluated and forecasted by the software PROTEON which compares the surface snow characteristics to different wind thresholds. The new software SYTRON generalises this approach to different elevations and aspects of the massifs.