| Title | Processed underway Thermosalinograph (TSG) observations from the Algoa Voyage 254, November 2018 |
|---|---|
| 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, between 01 November and 14 November 2018, during Voyage 254 on the RS Algoa. 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 West Coast Whale Cruise was conducted on the Algoa Voyage 254 between 1 and 14 November 2018. The cruise operated between the shelf, slope and offshore regions (<2000m depth) off the west coast of South Africa, between Cape Point (-34.36.111, 18.38064) and Groenriviermond (-30.8277, 17.52061). This cruise was undertaken for data collection as part of a collaborative project led by the Department of Environmental Affairs (DEA) in collaboration with the Whale Unit, Mammal Research Institute of the University of Pretoria, Department of Agriculture, Forestry and Fisheries (DAFF), National Oceanic and Atmospheric Administration (USA), Aqualie Institute (Brazil) and Oregon State University (USA). The greater programme is titled 'Large whale research - genetic relatedness, stock identification, abundance, feeding and migratory behaviours' and has two components, the east coast and west coast components. This cruise focused on the west coast humpback whales. |
| Methods | The SeaBird SBE45 Thermosalinograph (TSG) is used on the RS 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 Dataprocessing software. The software was set to record data at 6 second intervals for the duration of the cruise, between 01 November 2018 and 14 November 2018. 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 | 01 Nov 2018 – 14 Nov 2018 |
| Geographic extent |
Benguela Current Large Marine Ecosystem (BLMCE); shelf region on the west coast of South Africa
North: -29.0 |
| Vertical extent |
Max: -5.0 m Min: -5.0 m |
| Keywords | Algoa, Algoa 254, SOUTH ATLANTIC OCEAN, THERMOSALINOGRAPH, TSG |
| Related resources |
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