SADCP measurements in the Bransfield Strait in 2017

The kinematic structure of currents in the Bransfield Strait was measured over 50 transects across the strait using a Shipborne Acoustic Current Doppler Profiler (SADCP) onboard the R/V "Akademik Sergey Vavilov" (ASV) and "Akademik Ioffe" (AI) in 2017. The sections crossed all three basins 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. Teledyne RD Instruments Ocean Surveyor (TRDI OS) SADCPs with frequencies of 76.8 kHz (R/V ASV) and 38.4 kHz (R/V AI) were used for the data collection. During all our surveys the profilers were set in the narrowband mode, which increases the profiling range up to 700 m depth for 76.8 kHz SADCP and up to 1000 m depth for 38.4 kHz SADCP. We set 60 vertical bins of 16 m each with 8 m blank distance immediately below the transducer for the R/V ASV. The equivalent parameters for the R/V AI were 60 bins of 24 m each and 10 m blank distance. The draught of both ships is 6 m, which gives 22 m (R/V ASV) or 28 m (R/V AI) depths for the center of the first bin (the depth of the uppermost layer with velocity measurements). Time averaging of the raw data was performed over 120 s intervals. The data were collected using VmDas software.