Title Processed CTD continuous observations from the West Coast Physical Oceanography on the Africana Voyage 025, October 1984
Project West Coast Physical Oceanography
Authors

Gavin Tutt
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientific Technician; contact details: email: Gtutt@environment.gov.za

Tarron Lamont
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientist; contact details: email: tlamont@environment.gov.za

Publisher Department of Forestry, Fisheries and the Environment (2022)
Contributors

Contact Person: Gavin Tutt
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientific Technician; contact details: email: gtsglider@gmail.com

Contact Person: Tarron Lamont
Oceans and Coastal Research, Department of Forestry, Fisheries and the Environment (DFFE); role: Marine Scientist; contact details: email: tarron.lamont@gmail.com

Abstract This is processed downcast Conductivity-Temperature-Depth (CTD) continous data from the West Coast Physical Oceanography on the Africana Voyage 025, collected between 25 and 31 October 1984. The cruise operated in the Benguela Current Large Marine Ecosystem (BCLME) region on the west coast of South Africa. The objectives of this cruise included studying shelf circulation in the vicinity of Port Nolloth by placing three current meter moorings across the shelf; exploring the deep circulation in the Cape Basin which is thought to be a driving mechanism for the preponderance of southward flow observed on the shelf by placing a current meter in 3000m of water; recovering one current meter in the Cape Canyon and deploying two current meter moorings and a thermistor string near Cape Columbine and obtaining Conductivity-Temperature-Depth (CTD) data at these sites; collecting chemical samples and CTD data along a line between Port Nolloth to the deep current meter site, this included 100ml samples for analysis by M.J. Orren on routine CTD casts; a line of six coastal CTD stations was to be worked in the Hondeklipbaai upwelling tongue; the surface flow over the 1000m contour was to be studied using an acoustic drifter and samples were to be taken at various CTD stations for nitrogen cycling studies.
Methods Neil Brown MK3 and MK4 Conductivity-Temperature-Depth (CTD) instruments were used to measure pressure, temperature and conductivity through the water column during research and monitoring cruises between 1983 and 2000. Temperature was converted from the IPTS-68 scale to the ITS-90 scale, and salinity was computed from conductivity measurements on the 1978 Practical Salinity Scale, according to UNESCO (1991) algorithms. UNESCO (1993) quality control procedures were applied to the data, and obvious erroneous values resulting from problems including electronic spikes, data collection in air, inadequate flow through the conductivity cell, among others, have been removed. Any additional calibrations or corrections have been specified in each data file, where applicable and available.
Data
Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
Temporal extent 25 Oct 1984 – 30 Oct 1984
Geographic extent

Benguela Current Large Marine Ecosystem (BCLME) region on the west coast of South Africa

North: -29.0
South: -33.0
West: 15.5
East: 18.0

Vertical extent Max: -168.8 m
Min: -1.2 m
Keywords Africana, Africana 025, Conductivity, CTD, Depth, Neil Brown CTD, SOUTH ATLANTIC OCEAN, Temperature
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