Abstract:

Using the former Soviet Union daily snow depth data during 1948-1994 provided by the National Snow and Ice Data Center, USA,an index used to reflect the winter fresh snow depth was defined, the basic features of the variation of snow depth in both late Autumn and Winter as well as the winter fresh snow depth over Eurasian Continent are investigated. The possible linkages among them are disclosed by comparing the variabilities of them. Results from Empirical orthogonal function (EOF) analysis suggest that the leading EOF modes of both the winter fresh snow depth and winter snow depth show a coherent negative anomaly in the Eurasia Continent north to 50°N and positive anomaly in the south part. The winter fresh snow depth and winter snow depth show a consistent trend in the northern Eurasia Continent .Both of the EOF time series display a significant decadal fluctuation and the transition of interdecadal changes happened in the middle of 1970s. The second modes of EOF reflect a east-west diople pattern over the whole Eurasian Continent. Further analysis suggest that there is no correlation between late autumn snow depth anomaly and winter snow depth anomaly in aspects of both their spatial pattern and temporal evolution. The varibility of winter snow depth over Eurasian Continent are mainly decided by the variability of winter fresh snow depth but not that of the snow depth in late autumn．

Key words: Eurasian Continent, winter snow depth, spatial and temporal wariation, impacting factors