Climate Trend Estimation of the Powell Basin Hydrophysical Characteristics

The trend assessment of the dynamic state of the Powell Basin waters in the Weddell Sea was made on the basis of the hydrological data of the 79th cruise of the R/V AkademikMstislavKeldysh (January 16–February 6, 2020) and the World Ocean Database-2018 data for January-February from 1975 to 2020. At each node of the quarter-degree grid, a linear trend was constructed for the calculated values of the maximum buoyancy frequency and the maximum amplitude of the vertical component of the internal wave velocity. It is shown that the southwestern and northwestern parts of the Powell Basin differ significantly in their hydrophysical characteristics. In the northwest of the basin, the linear trend of the maximum buoyancy frequency is negative, the trends of the depths of the maximum values of the Väisälä-Brent frequency and the amplitude of the vertical velocity component are positive. In the southwestern part of the basin, the opposite is true: the trend of the maximum buoyancy frequency is positive, the trends in the depths of the maximum values of the Väisälä-Brunt frequency and the amplitude of the vertical velocity component are negative.