Processed underway Thermosalinograph (TSG) observations from the SAMBA Monitoring Line cruise on the Algoa Voyage 275, September 2021

Here we present the 6-second resolution processed Thermosalinograph (TSG) data collected on the Algoa Voyage 275 on the South Atlantic Meridional Overturning Circulation Basin-wide Array (SAMBA) Monitoring Line in the South-East Atlantic Ocean, between 13 September and 3 October 2021. A SeaBird SBE45 Thermosalinograph (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 Cape Town towards Slangkop and westwards to 0° E, in an easterly direction in the South Atlantic Ocean along the SAMBA Monitoring Line (34.5°S). The objectives of the cruise were to recover, service and deploy 10 CPIES/PIES on the SAMBA transect; attempt to locate and recover DFFE current meter mooring (M7), that could not be recovered during 2020 cruise; undertake full depth Conductivity, Temperature, Depth (CTD) casts along the SAMBA transect (37 stations) using containerised winch system; undertake chlorophyll, oxygen, nutrient and Dissolved Inorganic Carbon (DIC) sampling at CTD stations and underway along SAMBA transect; collect under-way Thermosalinograph (TSG); Surface Photosynthetically Active Radiation (SPAR) and Ship-mounted Acoustic Doppler Current Profilers (S-ADCP) data and deploy Argo floats and drifters.