Quality controlled, post-recovery ocean glider data from the eastern and central Agulhas Bank (South Africa) collected as part of SOLSTICE-WIO during March 2019.

Three quality controlled, post-recovery ocean glider datasets collected by buoyancy driven ocean gliders on the eastern and central Agulhas Bank (South Africa) during March 2019 are presented here. These data were collected as part of the Sustainable Oceans, Livelihoods and food Security Through Increased Capacity in Ecosystem research in the Western Indian Ocean (SOLSTICE-WIO) project (Global Challenges Research Fund under NERC grant NE/P021050/1), to investigate ecosystem health and resilience in the face of climate change in the Western Indian Ocean. To investigate the ecosystem functioning of the study region three buoyancy driven ocean gliders (units 424, 438 and sg550) were deployed alongside a research ship survey (EK188) in March 2019. Units 424 and 438 were Teledyne Webb Slocum G2 underwater glider with a maximum operating depth of 200 m. Both Slocum units were equipped with a thruster for additional propulsion when required. Unit sg550 was a Kongsberg M1 Seaglider with a maximum operating depth of 1000 m. Using a locally chartered vessel all three ocean gliders were deployed on 14th March 2019 in a mean water depth of 90 m at a nominal location of 26.950°E, 33.633°S. Units 424 and sg550 were recovered by RS Ellen Khuzwayo (EK188) on 31st March 2019 at 23.756°E, 34.346°S and 24.932°E, 34.923°S, respectively. Unit 438 suffered a technical failure 48 hours after its deployment, which required an emergency recovery on 25th March 2019 by RS Ellen Khuzwayo (EK188) at 25.531°E, 34.155°S. All three ocean gliders were equipped with integrated Sea-Bird CTD (conductivity, temperature, depth) instruments and Aanderaa oxygen optode sensors. Unit 424 was additionally fitted with a Rockland Scientific MicroRider mounted on the upper forward section of the glider collecting shear data. Unit sg550 was additionally fitted with a WETLabs ECO puck optical sensor measuring 470/695nm (Chlorophyll-a fluorescence), 650nm (optical backscatter), 370/460nm (coloured dissolved organic matter - CDOM) and a lab-on-chip nutrient sensor measuring in-situ nitrate+nitrite concentrations. Unit 438 was additionally fitted with a WETLabs ECO puck optical sensor measuring 470/695nm (Chlorophyll-a fluorescence), 700nm (optical backscatter), 370/460nm (CDOM), and an Imagenex ES853 (a single-beam 120kHz echo-sounder) collecting acoustic fishery data. Observations of temperature/salinity have been cross-calibrated against ocean glider data. Concentrations of dissolved oxygen and chlorophyll-a fluorescence have been calibrated against calibrated EK188 CTD data (Wihsgott et al., 2021). All CDOM and optical backscatter data are currently uncalibrated due to a lack of calibration data The shear, nitrate+nitrite and fishery acoustic data collected during this mission do not form part of this submission and will be available separately.