Estimation of Volume, Heat and Salt Transport Between the Bering Sea and the Pacific Ocean Through the Near Strait

The work is devoted to the quantitative assessment of volume, heat and salt transport through the Near Strait based on GLORYS12V1 data for the period 1993–2021. The paper shows that the predominant direction of water exchange through the strait is inflow from the Pacific Ocean to the Bering Sea. The influence of atmospheric forcing has been established. There is a pronounced seasonal variability in all three parameters, volume, heat, and salt transport, with maximum values recorded in winter and minimum values in summer. The monthly averaged volume transport through the strait varies from 2.8 Sv (1 Sv = 106 m3 · s−1) in September to 4.9 Sv in January, for the heat transport in winter it reaches maximum values of 1.0 × 1018 W, while summer values do not exceed 7.5 × 1017 W. Salt transport shows seasonal variability too: in the cold season, the monthly averaged values are 1.6 × 1015–1.8 × 1015 g · s−1 and in the warm season it does not exceed 1.3 × 1015 g · s−1. The analysis of interannual variability revealed extreme values: in 1995, 2017 and 2018, the maximum average daily volume transport exceeding 15 Sv was recorded, while the minimum values (less than −5 Sv) were observed in 1998, 2000 and 2021. The absolute peaks of salt transport (5.7 × 1015 g · s−1) and volume transport (15.6 Sv) were recorded in 1995, and the peak of heat transport (3.2 × 1018 W) occurred in 2017–2018. On the contrary, 2021 was marked by record low values of all parameters: heat transport reached −1.7 × 1018 W, salt transport −2.7 × 1015 g · s−1, and volume transport −7.6 Sv. The influence of mesoscale eddies on water exchange is described: an inflow in 2018 was formed when the Alaskan jet Stream passes through the strait in the absence of the blocking action of eddies or when the waters leave the periphery of the eddies in a northerly direction, while the negative transport rate (outflow) in 1998 was formed by “blocking” the penetration of the Alaskan Stream by mesoscale eddies with an increase in the North Aleutian slope current in the southeastward direction.