Posters

Poster Session 4, Thursday, October  6, 11:00–12:40

Poster 104

Ocean currents and optical properties of waters in the Bransfield Strait, Antarctica

The Bransfield Strait located near the tip of the Antarctic Peninsula is an important passage for the propagation of waters between the Bellingshausen and Weddell seas. Dynamical processes in the strait, such as ocean currents, eddies, and tidal motions play a crucial role in transporting nutrients, metals, and biota, especially krill aggregations, which affect the ecosystems of the Antarctic Peninsula region and surrounding waters of the Southern Ocean. Even though the Bransfield Strait is one of the most studied regions around the Antarctic continent, direct observations of water structure in the strait from research ships remain rare. In this study, we combine two approaches of direct measurements in the strait. First, we analyze a large dataset of current velocity observations performed at a series of transects across the strait during austral summer seasons in 2015 – 2022. These measurements were carried out using Shipborne Acoustic Current Doppler Profilers (SADCPs). Second, we use two detailed surveys performed in 2020 and 2022 onboard Russian R/V Akademik Mstislav Keldysh. These multidisciplinary surveys included measurements of ocean currents, their thermohaline structure, and distribution of optical properties of waters in the strait. Based on these data, we found that the flow of transformed waters from the Weddell Sea can be observed in the Western Basin of the strait. We also discuss how observed kinematic structure of currents in the strait affects optical water properties. This work was supported by the RSF Grant 22-77- 10004 and the grant for state support of young Russian scientists MK-1492.2021.1.5.

Dmitry Frey, Shirshov Institute of Oceanology, Russian Academy of Sciences, [email protected], 0000-0001-8141-9513

Pavel Salyuk, Ilichev Pacific Oceanological Institute, Far Eastern Branch of Russian Academy of Science, Vladivostok, Russia, [email protected]

Viktor Krechik, Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia, [email protected], 0000-0001-6440-060X

Eugene Morozov, Shirshov Institute of Oceanology, Russian Academy of Sciences, Moscow, Russia, [email protected], 0000-0002-0251-3454