Item: Research and developments on wind transport at meteo-france and its modelling
Title: Research and developments on wind transport at meteo-france and its modelling
Proceedings: 2002 International Snow Science Workshop, Penticton, British Columbia
Authors: Yves Durand, Gilbert Guyomarc'h, Laurent Merindol, Meteo-France, Centre d'Etudes de la Neige (Snow Study Centre)
Abstract: Snow drift modeling is a difficult challenge due to different factors as the large range of the working scales and the permanent interaction between snow, meteorological conditions and local orography. Nevertheless, these phenomena cannot be omitted in the framework of an automatic suite of snow modeling and avalanche hazard forecasting. The present version of this suite runs at a scale of about 400 km2 and provides the "large scale" conditions for wind and snow. The final purpose is to build a new local system, coupled with the larger system, at fine mesh where the drift effects can be modeled. An important task is the development of "downscaling operators" for the initialization of the local model on a realistic grid of 50m length. This scale, which exceeds the current accuracy of the automatic evaluation of wind and snow in mountainous conditions must be considered carefully. Once initialized with realistic conditions, the 2D drifting model (SYrRON2) is able to simulate the occurrence of blowing snow and to estimate the different snow mass exchanges by creep, saltation, suspension. The losses by sublimation as well as the modifications of density and crystal morphology are also treated. The center of the modeled domain corresponds to an experimental observation site, located in the French Alps at an elevation of about 2700 m a.s.l where drifting snow events have been investigated for 10years. These observations allow an useful validation of the modeled results.
Keywords: snow drifting, snow cover ablation, snow cover accumulation, snow evaporation, snow modelling
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