Analysis of Many-Year Variations in River Runoff into the Arctic Ocean

Statistical analysis of long-term hydrological observations has shown that the interannual variations in the total river runoff into the Arctic Ocean can be considered as a stationary process. Similar are the variations in the annual runoff of the Ob, Lena, and rivers of the northwestern Asia. However, some components of the total runoff into the Arctic Ocean feature distinct and fairly complicated disturbances in the homogeneity of runoff variations. For example, variations in the annual runoff of the Yenisei River have a distinct nonmonotonic trend: the runoff systematically decreased till the late 1950s and increased since the late 1960s. The rivers of the European part of the Arctic Ocean drainage basin featured a decrease in the amplitude of variations in runoff during the past decades. Rivers of the northwestern America and northeastern Asia featured a regular increase in the amplitude of runoff variations and their autocorrelation since the late 1960s.