Spatiotemporal Stationarity of Laptev Sea Polynyas

This study examines the seasonal and interannual variability of the location and area of flaw polynyas in the Laptev Sea. It uses Arctic and Antarctic Research Institute (AARI) regional charts of ice conditions in the SIGRID-3 format covering the years from 1997 to 2023 as initial data. The analysis is based on an algorithm developed previously for calculating the frequency of occurrence of multiple vector polygon intersections. To visualize areas with a 50% polynya occurrence frequency, a series of monthly charts was produced for December through May. The annual average time series for this indicator reveals a positive trend. Seasonally, the polynyas exhibit a distinct pattern, beginning as open and extensive features in the western part of the sea. During spring, this pattern reverses, with the eastern polynyas increasing in extent as the western ones decline. This positive trend is observed in both parts of the sea throughout the season, with significant values noted during the spring months (April and May) in the western area. This is particularly important, as the polynya during this period marks the beginning of summer melting, which can have significant implications. By analyzing all polynyas polygons from the period under study (1997–2023), we identified polygons of recurring polynyas (with a 75% occurrence frequency) and stable polynyas (with a 50% occurrence frequency). It was discovered that the criterion for recurring polynyas corresponds only to a small section along the fast ice of Teresa Klavenes and Thaddeus bays. Notably, the Western New Siberian polynya has a 50% occurrence frequency and is located in a narrow strip northwest of Kotelny Island. Previous studies indicate that this section is part of the Great Siberian Polynya; however, it is evident that its development has been limited in recent decades. In contrast, the sections of the Northeastern Taimyr and Anabar-Lena polynyas are significantly larger and exhibit high occurrence frequencies. This scenario may be linked to changes in large-scale atmospheric circulation and the dominance of western circulation patterns.