STUDYING POLYNYA OCCURRENCE TERMS AND DURATION ON THE SHIPPING ROUTES IN THE LAPTEV SEA

The dynamics of the development of the Lena polynya formed on the shipping routes of the Northern Sea Route in the Laptev Sea and its influence on the conditions of navigation in the Arctic are studied. During the period of winter-spring navigation in the Laptev Sea, the Great Siberian polynya, which is located near the fast ice border and creates good opportunities for winter navigation on the Northern Sea Route, is formed. This problem is important to ensure year-round navigation in the Eastern Sector of the Northern Sea Route. The hypothesis that the terms of a polynya occurrence can significantly affect the average rate of its growth is tested in the study. When checking, the results of the GLORYS12v1 global reanalysis and standard methods of mathematical statistics are used. On the example of the polynya section located on the estuary seashore of the largest navigable channel of the Lena River Delta - Bykovskaya, the validity of the hypothesis is confirmed. Steady trends in the change in the polynya formation terms towards earlier dates in the modern period are revealed. A high probability of improving the conditions of navigation in this region in 2020-2040 is noted. At the same time, with further warming of the Siberian climate, the opposite process, namely, the freezing of a polynya that formed too early, which will lead to a cooling of the climate in the region and a deterioration in navigation conditions, is possible. Comparing the results obtained with other studies that are devoted to the construction of general routes for ships in various ice conditions, it is possible to identify trends that the actual routes during independent navigation pass along the forming polynyas, regardless of the physical principle of their formation, then the choice of general routes for ships in the areas of polynya distribution will be promote more intensive and safe shipping. What requires accurate forecasts of its size and position. The relevance of the research results for forecasting year-round navigation, both for independent navigation of ships with a high ice class, and in the development of plans for using icebreaking escort of ships, is noted.