Impact of Floods in the Kolyma River Delta on Navigation Conditions in the East Siberian Sea

Abstract

Problem of improving the quality of medium- and long-term forecasting of changes in ice conditions in the Northern Sea Route, and in particular in the east Siberian sea, where one of the methods of selecting waterways is the passage of ships in areas of ice-covered polynya. The hypothesis is verified that during the summer months, such changes may be significantly influenced by the timing of the onset of high water in the Kolyma River delta. Data from the global reanalysis GLORYS12v1 supported by the European Copernicus Marine Service were used as factual material on the ice cover and levels of the East Siberian Sea in the months of May to October 1993-2019. The analysis is based on mathematical models of the NEMO family verified by satellite altimetry data. Using the developed methodology, the dates of abrupt changes in level and sea ice extent on the Kolyma River estuarine seashore have been estimated for selected periods of the year. The study uses statistical methods to confirm the validity of the stated hypothesis for a number of areas of the East Siberian Sea, through which the shipping routes of the Northern Sea Route pass. It has been established that the greatest influence of flood timing on ice conditions and navigation conditions in such areas takes place in July. It is shown that early floods in the Kolyma delta generally lead to improvement of ice conditions, while late floods lead to complication of ice conditions. The identified relationships are recommended for use in forecasting changes in ice conditions. It has been suggested that with further climate warming and shifting of flood dates to earlier dates, the complication of ice conditions due to freezing of the formed polynya is not excluded.