Processed underway Thermosalinograph (TSG) observations from the South Atlantic Meridional Overturning Circulation Basin-wide Array (SAMBA) Monitoring Line cruise on the Algoa Voyage 291, March 2023

Here we present the 6-second resolution processed Thermosalinograph (TSG) data collected between 01 March and 09 March 2023 during the South Atlantic Meridional Overturning Circulation Basin-wide Array (SAMBA) Monitoring Line cruise on the RS Algoa Voyage 291. A SeaBird SBE45 TSG is used to opportunistically collect underway near-surface temperature and conductivity measurements during research and monitoring cruises. Water is continuously pumped to the TSG from an intake located in the hull of the vessel, and the observations are continuously interfaced with navigational information. A temperature sensor close to the intake provides temperature measurements of the incoming water (T1). The temperature of the water inside the conductivity cell (T2) is used to accurately compute salinity (S) from the conductivity measurements (C). The cruise operated from Slangkop, off Cape Town, westwards to 15° E, in the South Atlantic Ocean along the SAMBA transect. The objectives of the cruise were to deploy two Acoustic Doppler Current Profiler (ADCP) moorings (M3 & M4) along the Integrated Ecosystem Programme (IEP)’s Scarborough Monitoring line to collect current data on the Benguela Jet Current; deploy four tall moorings on the SAMBA transect (M7; M8; M9 & M10), incorporating ADCP’s and Sea-Bird Microcats; complete Conductivity, Temperature, Depth (CTD) casts (using the hydrographic winch), before each mooring deployment, for the calibration of the SeaBird microcats mounted on the moorings; collect underway Thermosalinograph (TSG); Surface Photosynthetically Active Radiation (SPAR); Underway PCO2 and Ship-mounted Acoustic Doppler Current Profilers (S-ADCP) data and provide training to newly employed Department of Forestry, Fisheries and the Environment (DFFE) personnel and interns.