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Field measurements of snow-drift threshold and mass fluxes, and related model simulations

JDoorschot, Judith ; Lehning, Michael ; Vrouwe, Anouck

In: Boundary-Layer Meteorology, 2004, vol. 113, no. 3, p. 347-368

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    Titre
    • Field measurements of snow-drift threshold and mass fluxes, and related model simulations
    Auteur
    • JDoorschot, Judith. Swiss Federal Institute for Snow and Avalanche Research, Flüelastrasse 11, 7260, Davos Dorf, Switzerland
    • Lehning, Michael. Swiss Federal Institute for Snow and Avalanche Research, Flüelastrasse 11, 7260, Davos Dorf, Switzerland
    • Vrouwe, Anouck. Swiss Federal Institute for Snow and Avalanche Research, Flüelastrasse 11, 7260, Davos Dorf, Switzerland
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Boundary-Layer Meteorology, 2004, vol. 113, no. 3, p. 347-368. Kluwer Academic Publishers
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:321731
    Summary
    Field measurements were carried out to calculate the threshold friction velocity for snow saltation, and mass fluxes during snow drift. The wind was measured in three components by an ultrasonic anemometer, and the mass fluxes were determined using an optical sensor (‘snow particle counter'), acoustic sensors (‘Flowcapt') and mechanical traps. The threshold friction velocity was found to be correlated to the grain size (R2=0.75). The mass flux measurements were compared with numerical simulations of snow drift, and it was demonstrated that the maximum snow transport takes place at shear stress values of roughly two times the average shear stress over 20 min. By implementing a probability distribution for the shear stress the mass flux was simulated with only the mean measured value of the shear stress as input. This procedure enables the future use of the numerical model for operational applications