DYNAMICS OF SNOW STORAGES IN FORESTS AND FIELDS OF RUSSIAN PLAINS UNDER CLIMATE CHANGES

Abstract

In 1966-2010, snow surveys were simultaneously performed in forests and fields on the Russian plain territory. This made it possible to analyze characteristics of snow storages on fields and in forests as well as a dynamics of them under the present-day climate changes. Data of 81 weather stations located on the territory were used. According to data of these stations for the period 2001–2010 we obtained the following estimates for the maximal snow storage values, on average: for 20 stations located on the European territory of Russia to the north of 60° N –167 mmin forests and 162 on fields; for 44 stations to the south of 60° N – 118 and116 mm, respectively; for 10 stations in the south of West Siberia – 125 and107 mm; and for 7 stations in the East Siberia – 64 and70 mm. As one can see the last region is characterized by the opposite relation between forest and field conditions. Comparison of these values with similar data for the period 1966-2000 demonstrated that maximal snow storages decreased in forests by 7% but in fields they increased by 2%. The ratio of the maximum snow storage in the forest to their value in the field (i.e. a coefficient of snow reserve) for the periods 1981–1990, 1991–2000, and 2001–2010 are 1.15; 1.11 and 1.03, respectively. One of the reasons for the equalization of snow storage in forest and field may be changes of intensity and duration of snowstorms. In the calendar winters of 2001-2010, the average number of observations at weather stations with wind speeds over 10 m/s decreased relative to 1966-2010: in the European part of Russia by factor of 8.9 times, and in Western and Eastern Siberia – by 2.0 and 1.9 times, respectively. In the European part ofRussia, the number of observation periods when wind speed from 6 to 10 m/s was observed decreased by 1.9 times.