Cold ridge formation mechanisms on the Agulhas Bank (South Africa) as revealed by satellite-tracked drifters

The formation of the cold ridge, a seasonal mid-shelf upwelling feature on Agulhas Bank, is investigated from combination satellite-tracked surface drifters, in situ current and temperature data, as well satellite sea (SST) chlorophyll-a (Chl-a). observational data showed coastal along Tsitsikamma coast to be induced by easterly wind austral summer, with coexistent westward flowing current. Under this regime, drifters moved west onto water, thereafter following southward-curved 100 m isobath. Satellite observations March–April 2008 increased south-westward advection wind-driven upwelled water during an Current intrusion that resulted classically shaped ridge. Also interest was passing Natal Pulse south-eastern shelf edge Bank July 2007. This generated large cyclonic eddy Bight attendant warm plume swept over adjacent shelf. Two idle positioned at time, immediately Pulse, were rapidly advected offshore curved isobath, confirming long-thought association ridge cyclone. A moored meter (1.5 km offshore) effect nearshore. Drifter trajectories show accelerated flow side recirculation towards east its shoreward side. These findings strongly support Westward Transport Hypothesis where squid paralarvae are inshore breeding grounds, food maxima interior central improve their chances survival can therefore have important implications for management South African chokka fishery.