IMPACT OF FLOODS IN THE KOLYMA RIVER DELTA ON NAVIGATION CONDITIONS IN THE EAST SIBERIAN SEA

Abstract

The problem of improving the quality of medium- and long-term forecasting of changes in the ice situation on the Northern Sea Route, and in particular in the East Siberian Sea, where one of the methods for choosing waterways is the passage of vessels in the areas of flaw polynya, is considered. The hypothesis that in the summer months such changes can be significantly affected by the terms of floods onset in the Kolyma River Delta is tested. The data of the GLORYS12v1 global reanalysis supported by the Copernicus Marine Service are used as factual material on the ice cover and levels of the East Siberian Sea in the months from May to October of 1993-2019. The reanalysis is based on mathematical models of the NEMO family, verified using altimetry data from satellite measurements. Using the developed methodology for the selected periods of the year, the dates of sharp changes in the level and ice cover on the pre-estuary seaside of the Kolyma River are estimated. Using statistical methods, the validity of the stated hypothesis for a number of the East Siberian Sea areas, along which the shipping lanes of the Northern Sea Route pass, is confirmed. It has been established that the greatest influence of the floods terms on the ice situation and navigation conditions in such areas takes place in July. It has been shown that early floods in the Kolyma delta generally lead to an improvement in the ice situation, and late floods lead to its complication. The identified relationships are recommended for use in forecasting changes in ice conditions. The assumption that with further climate warming and a shift in the flood terms to earlier dates, it is possible that the ice conditions will become more complicated due to the freezing of the formed polynya, is made.