- 1Environmental Affairs, Department of Forestry Fisheries and the Environmental, South Africa (haloissufo@gmail.com)
- 2Nansen-Tutu Centre for Marine Environmental Research, Department of Oceanography, University of Cape Town, South Africa
- 3Department of Oceanography, University of Cape Town, South Africa
- 4Nansen Environmental and Remote Sensing Centre, and Bjerknes Centre for Climate Research, Bergen, Norway
- 5Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d’Océanographie Physique et Spatiale (LOPS), IUEM, 29280, Brest, France
- 6Nansen Environmental and Remote Sensing Centre, and Geophysical Institute, University of Bergen, Bergen, Norway
A regional ocean model was used to study the influence of the Madagascar Ridge on the circulation and eddy variability in the Agulhas Current system. In the control experiment, the model was run with a realistic bathymetry, whereas in the idealized run the bathymetry was modified by flattening Madagascar Ridge. When the Ridge was suppressed, no obvious changes were observed in the large-scale circulation. However, integrated transports revealed an excess of about 10 Sv (1 Sv = 106m3 s−1) in the recirculation of the greater Agulhas Current system. Dynamic and statistically (p < 0.05) significant changes were observed at the mesoscale variability. Composite analysis of the radial distribution of the eddy azimuthal velocity, surface height, and relative vorticity within the Ridge domain in the experiments revealed that the presence of the Madagascar Ridge determines the emergence of a secondary class of large anticyclonic eddy types in the region, the ”Madagascar rings”.
How to cite: Halo, I., Raj, R., Penven, P., Lamont, T., Ansorge, I., and Johannessen, J.: Influence of the Madagascar Ridge on Eddy Variability in the Agulhas Current System: A Modelling Study, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18402, https://doi.org/10.5194/egusphere-egu25-18402, 2025.
