摘要:Daily snow depth (SD) and snow cover extent around 820 stations are used to
analyse variations in snow cover characteristics in Northern Eurasia, a region that
encompasses the Russian Federation. These analyses employ nearly five times
more stations than in the previous studies and temporally span forty years. A
representative judgement on the changes of snow depth over most of Russia is
presented here for the first time. The number of days with greater than 50% of
the near-station territory covered with snow, and the number of days with the
snow depth greater than 1.0 cm, are used to characterize the duration of snow
cover (SCD) season. Linear trends of the number of days and snow depth are
calculated for each station from 1966 to 2007. This investigation reveals regional
features in the change of snow cover characteristics. A decrease in the duration of
snow cover is demonstrated in the northern regions of European Russia and in
the mountainous regions of southern Siberia. An increase in SCD is found in
Yakutia and in the Far East. In the western half of the Russian Federation, the
winter-averaged SD is shown to increase, with the maximum trends being observed
in Northern West Siberia. In contrast, in the mountainous regions of southern
Siberia, the maximum SD decreases as the SCD decreases. While both snow cover
characteristics (SCD and SD) play an important role in the hydrological cycle, ecosystems
dynamics and societal wellbeing are quite different roles and the differences in their
systematic changes (up to differences in the signs of changes) deserve further attention.