An approach to assessing changes in snow cover: an example from the former Soviet Union

The question of what are the most suitable indices of temporal change in snow cover conditions, and the most appropriate means for their detection is important in monitoring climate system changes. The extent and variability of seasonal snow cover is recognized to be an important climatic and hydrologic parameter. Trends in snow cover are also expected to serve as an indicator of any global climatic changes.Passive microwave data afford the possibility of all-weather mapping of daily snow extent, and potentially water equivalent, with a spatial resolution of 25-50 km is well suited for regional and global climate modeling. Newly-released snow depth data for stations in the former Soviet Union are described and for a ten-day average are compared with passive microwave-derived estimates. Possible sources of differences are discussed including problems related to wet snow, mountainous terrain and vegetation, as well as errors caused by the interpolation of station data used for validation.