ASSESSMENT OF THE SEA ICE AGE COMPOSITION AND THE FORMING OF MAIN FACTORS IN THE LAPTEV SEA

The age composition of the Laptev Sea ice cover is considered. The seasonal course of the ice development, as well as interannual changes, was estimated from October to May in 1997-2024. Regional Laptev Sea charts of the ice conditions, compiled by the AARI (available in the electronic catalog of the World Sea Ice Data Center), were used as the data source. Regional charts are the result of analyzing satellite information in 2-3 days made as SIGRID-3 format. The spatial and temporal variability of sea ice with different stages of development (new ice, nilas, gray and gray-white ice, one-year thin, medium, thick and old ice) was analyzed using the method of probability calculated by polygon intersections.

Assessing the interannual variability of age composition during winter season, a tendency was revealed to shift the terms of the transition to the next age gradation to later ones, as well as a tendency to reduce the amount of the old and thick one-year ice, while the number of medium and young ice increased. The main factors determining the interannual changes in the area of ice of various age gradations for certain areas of the Laptev Sea were also considered. For this purpose, physico-statistical equations with the highest coefficients of correlation and determination were constructed, and optimal combinations of predictors were found to describe changes in the age composition of the sea ice cover.