First hydrographic evidence of the southeast Madagascar upwelling cell

Hydrographic sections were conducted south of Madagascar during the Agulhas Current Sources EXperiment (ACSEX-2) cruise survey in March 2001. The East Madagascar Current (EMC), presumably one of the sources of the Agulhas Current, was crossed four times over the Madagascar ridge. The upwelling cell, at the southeastern tip of Madagascar (inshore of the EMC), was hydrographically highlighted for the very first time during ACSEX-2. The behavior of the EMC south of Madagascar is studied using both hydrographic data and satellite imagery. At the southeastern end of Madagascar, the EMC turns westward and the dramatic change in the shape of the shelf favours the development of a cyclonic eddy that is embedded between the EMC core and the coast. The upwelling is then associated to the presence of this eddy and to wind favorable conditions.