Nonuniform Distribution of Tundra Snow Cover in Eastern Siberia

Abstract

Characteristics of snow cover in a small watershed in Arctic tundra near Tiksi, eastern Siberia, were studied by observation and model simulation. First, helicopter observation, snow survey on three traverse lines, and trigonometric survey of snowdrift were carried out at the end of the winters of 1999 and 2000 to estimate the amount and distribution of snow. The observed locations of snowdrifts in the two years were mostly the same. The area of the snowdrift, including shallow snowdrifts, was larger in the year of high winter precipitation than in the year of low winter precipitation. The snowdrifts were formed on the riverbed and lee sides of cols rather than on steep leeward-facing slopes. Second, snow distribution was simulated using a snow distribution model. The results of simulated snow distribution at the end of winter agreed well with the results of the observations. The results of the simulations showed that approximately 40% of winter precipitation was sublimated. The simulations also indicated that snowdrifts were formed in limited areas such as the valley bottom and riverbed in the first half of winter because of strong wind conditions. In the latter half of winter, when strong wind was rare, shallow snowdrifts were formed in various areas.