| Title | Processed underway Thermosalinograph (TSG) observations from the SAMBA Monitoring Line cruise on the Algoa Voyage 275, September 2021 |
|---|---|
| Project | South Atlantic Meridional Overturning Circulation Basin-wide Array (SAMBA) |
| Authors |
Leon Jacobs Marcel van den Berg Tarron Lamont |
| Publisher | Department of Forestry, Fisheries and the Environment (2023) |
| Contributors |
Contact Person: Leon Jacobs Contact Person: Marcel van den Berg Contact Person: Tarron Lamont |
| Abstract | 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. |
| Methods | The SeaBird SBE45 Thermosalinograph (TSG) is used on the Algoa for the collection of underway near-surface temperature and conductivity measurements. The underway seawater is obtained from a depth of 5m below the surface and pumped through the TSG. Data is collected using the most recent SeaBird (SBE) SeaSave software and processed using the most recent SBE data processing software. The software was set to record data at 6 second intervals for the duration of the cruise, between 13 September 2021 and 03 October 2021. Data was collected in the southern part of the Benguela Current Large Marine Ecosystem (BCLME) region on the west coast of South Africa. Unreliable TSG measurements can result from a variety of problems encountered during the cruises, including insufficient water flow, extreme air bubbling during severely adverse weather conditions, debris trapped in the system, or a variety of electronic failures. Detailed visual inspection of the ship trajectory and TSG measurements, as well as comparisons with other concurrent and historical near-surface measurements, and expert knowledge of local conditions, were used to identify and remove all unreliable data. |
| Data | |
| Temporal extent | 13 Sep 2021 – 03 Oct 2021 |
| Geographic extent |
Benguela Current Large Marine Ecosystem (BLMCE); shelf region on the west coast of South Africa
North: -33.0 |
| Vertical extent |
Max: -5.0 m Min: -5.0 m |
| Keywords | Algoa, Algoa 275, SOUTH ATLANTIC OCEAN, THERMOSALINOGRAPH, TSG |
| Related resources |
|