SADCP measurements of several eddies in the Southwest Atlantic in 2016-2022
Description
The kinematic structure of several cyclonic and anticyclonic eddies in the Southwest Atlantic was measured over 6 transects using a Shipborne Acoustic Current Doppler Profiler (SADCP) onboard the R/V Akademik Sergey Vavilov and Akademik Mstislav Keldysh in 2016 - 2022. The measurements were performed during 5 oceanographic cruises in November 2016, March 2017, October 2017, October 2018, January and February 2022 (the data of cruise in 2022 contains two transects across the zone with intense eddies). These mesoscale eddies are formed at the Brazil - Malvinas Confluence zone as a result of the collision of two major western boundary currents in the Southwest Atlantic: the cold equatorward Malvinas Current and the warm poleward Brazil Current. Teledyne RD Instruments Ocean Surveyor (TRDI OS) SADCPs with a frequency of 76.8 kHz 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 600-900 m depth. We set 60-100 vertical bins of 8-16 m each with 8 m blank distance immediately below the transducer. The draught of both ships is 6 m, which gives 18-22 m depth 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 and processed using WinADCP software.