Item: Modelling snow redistribution by wind - Low Tatras, Slovakia
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Title: Modelling snow redistribution by wind - Low Tatras, Slovakia
Proceedings: International Snow Science Workshop Proceedings 2018, Innsbruck, Austria
Authors:
- Anna Seres [ University of Miskolc, Miskolc, Hungary ]
Date: 2018-10-07
Abstract: A submodule of AvalMap, a snowpack model developed by the author (Seres, 2018), models snow redistribution by wind to incorporate it in the final avalanche danger maps it produces. As a first step 10 minute wind measurements are averaged as vectors to get one speed, direction and duration value at each timestep in AvalMap. These values are then modified by a factor based on macro (general shape of the mountain and distance from ridge) and micro terrain features (curvature, slope and aspectwind direction ratio) to spatially distribute the point data. Then, as a second step snow transport is calculated based on the ratio of shear velocity (from logarithmic wind profile), to threshold shear velocity (equation modified from Liston et al. (2007)). Flux, the potential carrying capacity of the wind is calculated by an equation from Kind (1981), which is also based on shear and threshold shear velocity. Difference of the fluxes is then determined for each pixel from the direction of the wind, to derive the amount of snow that could actually be carried away or deposited. Sublimation and densification in the carried snow are also considered. The amount of snow actually transported depends on the temperature, height and density of the available snow layers. By putting these all together we determine the spatial distribution of wind deposited snow by considering the deposition areas indicated by the difference of the fluxes, the distance from the ridges and the time the air spends at each pixel by the given wind speed as well.
Object ID: ISSW2018_P08.2.pdf
Language of Article: English
Presenter(s):
Keywords: wind, snow, transport, redistribution.
Page Number(s): 726-730
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