Hydrological and Hydrochemical Structure of the Waters of the Bransfield Strait in January 2022

Abstract—The article studies the abiotic characteristics in waters of the Bransfield Strait in January 2022. The cross-section of January 2020 was repeated from the Antarctic Peninsula to the Southern Shetland Islands; new data were also obtained: two cross-sections in the eastern and western parts of the strait. The scheme of currents in the Strait reflects modern knowledge; absolute values have been measured up to 50 cm/s in the northeast direction and up to 35 cm/s in the southwest. In the studied area, modified waters of the Bellingshausen Sea are clearly distinguished (warm and least saline, with reduced values of total alkalinity and all nutrients); modified Weddell Sea water (colder and more saline, with reduced values of silicates and nitrates), as well as Circumpolar Deep Water in the 200–450 m layer (warm and salty, with low values of dissolved oxygen and pH and increased content of phosphates, silicates. and nitrates). In bottom waters of the strait, there were no serious changes in structure. The amplitude of the interannual variability of the abiotic characteristics of Bransfield Strait waters is poorly expressed, nevertheless it can serve as a climate change marker in the Southern Ocean.