CTD and LADCP measurements in the Bransfield Strait in February-March 2022
The thermohaline and kinematic structures of currents in the Bransfield Strait were measured over 4 sections across the strait using a Conductivity-Temperature-Depth (CTD) and Lowered Acoustic Current Doppler (LADCP) profilers onboard the R/V "Akademik Mstislav Keldysh" (AMK) in February-March 2022. The profilers were mounted on a General Oceanics GO1018 rosette water sampler. The water sampler was equipped by a Valeport VA500 altimeter allowing measurements close to the ocean bottom (3–7 m above the seafloor). An Idronaut Ocean Seven 320plus CTD probe was used for the measurements together with an MKplus Deck Unit. The CTD data were collected using standard package REDAS5. The declared accuracy of CTD measurements is 0.001°C for temperature and 0.001 mS/cm for conductivity sensors. The LADCP data measured by TRDI WorkHorse Monitor 300 kHz profiler were processed using programming package LDEO Software version IX.10. The data from Shipborne Acoustic Current Profiler (SADCP) TRDI Ocean Surveyor 75 kHz were used for more reliable data processing in the upper ocean layer. A total of 34 stations were carried out along the sections. These sections crossed the Central Basin of the Bransfield Strait and the main flows in the strait including the Bransfield Current and the southward flow of Weddell Sea waters along the Antarctic Peninsula. The work in the lowered mode is important for studies of deep and bottom currents. The data allow us to evaluate thermohaline and kinematic properties of the currents as well as their changes along the strait.