Strong Snow-Storms, their Effect on Snow Cover and Snow Accumulation

Abstract

Abstract Snow-drifts have been studied by many researchers both in field and laboratory conditions, however these investigations have been carried out mostly at wind speeds up to 20 m/s whereas in many areas of our planet snow-storms occur at winds up to 40 m/s and more. During the winter seasons of 1972-76 the authors carried out a great number of experiments with an artificial snow-storm in a special wind tunnel 27 m long. The wind speeds reached 40 m/s (60-65 m/s at the 10 m anemometer height). The existing theories and hypotheses of snow-drifting, and in particular the “diffusion" model, were tested in a series of the experiments. These have not confirmed the assumption of the Australian scientists on the decisive role of diffusion in drift mechanism at large wind speeds. The problem of strong snow-storm effect on snow accumulation on avalanche-danger slopes, in particular, wind redistribution of snow is no less important. The results obtained may be used for the determination of snow accumulation in avalanche starting zones due to deflation. This is especially important for forecasting very dangerous and frequently-occurring avalanches due to snow-storms. The investigations performed enable us to estimate the snow deposition produced by strong and superstrong snow-storms, to account for the peculiarities of such snow-storms and the means of protection, to forecast snow distribution in mountainous regions, and to define the role of snow-storms in glacier mass balance.