Blowing Snow Sublimation Research Articles

The Prairie Blowing Snow Model: characteristics, validation, operation

Physically based algorithms that estimate saltation, suspension and sublimation rates of blowing snow using readily available meteorological and land use data are presented. These algorithms are assembled into a model, the Prairie Blowing Snow Model (PBSM), and used to describe snow transport on fields in a Canadian Prairie environment. Validation tests of PBSM using hourly meteorological data indicate differences between modelled and measured seasonal snow accumulations between 4 and 13%. Application of the blowing snow model using meteorological records from the Canadian prairies shows that the annual proportion of snow transported above any specific height increases notably with mean seasonal wind speed. An observed decrease in annual blowing snow transport and sublimation quantities with increasing surface roughness height becomes more apparent with higher seasonal wind speeds and temperatures. The annual quantity of snow transported off a fetch increases with fetch length up to lengths of between 300 and 1000 m, then remains relatively constant or slowly declines. Within the first 300 m of fetch 38–85% of annual snowfall is removed by snow transport, the amount increasing with wind speed. Beyond 1000 m of fetch, blowing snow sublimation losses dominate over transport losses. In Saskatchewan, sublimation losses range from 44 to 74% of annual snowfall over a 4000 m fetch, depending on winter climate. Notably, as a result of steady-state transport, the sum of snowcover loss due to blowing snow transport and sublimation does not change appreciably from its 1000 m fetch value for fetches 500 to 4000 m. The transition from primarily transport to primarily sublimation losses at the 1000 m fetch distance may be useful in assessing the effect of scale in snow hydrology.