Seasonal simulation of drifting snow sublimation in Alpine terrain

Authors

  • Christine D. Groot Zwaaftink,

    Corresponding author
    1. WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
    2. CRYOS, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
    • Corresponding author: C. D. Groot Zwaaftink, WSL Institute for Snow and Avalanche Research SLF, Flüelastrasse 11, CH-7260 Davos Dorf, Switzerland. (groot@slf.ch)

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  • Rebecca Mott,

    1. WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
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  • Michael Lehning

    1. WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland
    2. CRYOS, School of Architecture, Civil and Environmental Engineering, EPFL, Lausanne, Switzerland
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Abstract

[1] We estimate seasonal drifting snow sublimation at a study site in the Swiss Alps with the numerical model Alpine3D using external wind fields from the Advanced Regional Prediction System on a high-resolution grid (10 m). Novel in the field of snow transport modeling, the transport module of Alpine3D accounts for the feedbacks among drifting snow sublimation, snow concentration, temperature, and humidity of the air in three dimensions. Due to these feedbacks, drifting snow sublimation is a self-limiting process. Model results show that the domain averaged drifting snow sublimation over a season is small (about 0.1% of precipitation) but spatially highly variable. Simulation results show strongest seasonal reduction of snow amount by 1.8% due to drifting snow sublimation in a leeward slope during SE wind. This can be explained by the generally warmer and dryer conditions during events with SE wind. In the Wannengrat study area, which covers typical alpine terrain, drifting snow sublimation is thus only significant locally or on short time scales. Note that we only consider drifting and blowing snow in the absence of concurrent precipitation. Furthermore, our results show that drifting snow sublimation is much smaller than surface sublimation in this area.

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