Benguela Current

The cold, nutrient rich waters that upwell from around 200–300 m (656–984 ft) depth in turn fuel high rates of phytoplankton growth, and sustain the productive Benguela ecosystem.

There is however a well-defined thermal front between the waters associated with the Benguela Upwelling System and those of the eastward flowing Atlantic currents which are not deflected northward by the African continent.

[3] While upwelling promotes abundant primary and secondary production in the upper parts of the water column and near the coast, deeper waters with limited oxygen exchange create hypoxic areas called oxygen minimum zones at the coastal shelf and upper coastal slope.

[5] Similar to the Pacific El Niño, a thick slab of warm, nutrient-poor water enters the northern part of the Benguela upwelling system off the Namibia coast about once per decade.

[5] One research team has shown that the Benguela Niño is caused by winds in the west-central equatorial Atlantic Ocean that propagate as subsurface sea temperature anomalies to the African coast.

[6] A recent study has demonstrated the importance of local winds in the development of the Benguela Niño off the coast of Namibia and Angola.

Benguela Current in the South Atlantic Gyre
The courses of the warm Agulhas current (red) along the east coast of South Africa, and the cold Benguela current (blue) along the west coast, originating in the Indian Ocean and Atlantic Ocean respectively. Note that the Benguela current does not originate from Antarctic waters in the South Atlantic Ocean, but from upwelling of water from the cold depths of the Atlantic Ocean against the west coast of the continent. The two currents do not "meet" anywhere along the south coast of Africa.
The red areas show major upwelling areas. The Benguela Current is on the southwest coast of Africa.
Map of the mean concentration of chlorophyll- a in the oceans surrounding Southern Africa. Note the very high concentrations along the west coast, due to the upwelling of nutrient-rich water from the cold depths of the South Atlantic Ocean, forming the Benguela Current.