Benguela Current

Benguela Current

The frigid waters of the north-flowing Benguela current move from the western coast of South Africa, Namibia and Angola towards north and northwest up to the line where it joins the southern equatorial current which is already a warm current. Its waters are cold because there are very deep waters that were brought upward due to the rotation of Earth from west to east. This upward movement of deep waters are sometimes increased by planetary winds from east to west (southern Trade winds) which blow west from the Kalahari Desert towards the ocean. Obviously, this wind creates a displacement of top ocean waters from the African coast to the west deviating to the northwest (to the left) because of the Coriolis Effect and this displacement causes deep waters to move upwards to replace coastal waters moving west.

Boundaries

The Benguela current forms the eastern boundary of the South Atlantic subtropical gyre. Its sources include Indian and South Atlantic subtropical thermocline water; saline, low-oxygen tropical Atlantic water; and cooler, fresher deep water. The Benguela current is 2-300 km wide and widens further as it flows north and northwest. Its western, seaward edge is ill-defined, with many temporary and seasonal eddies.

Effect

Where the icy Benguela and the warm, south-flowing Agulhas current mix, there is a richly productive marine ecosystem off the Cape of Good Hope but storms and turbulence above.

The cold current creates the desert conditions of the shore of Namibia, and the persistent fogs of the Skeleton Coast and Namib Desert. A Benguela El Niño effect has been detected, less intense and less frequent than the Pacific Ocean phenomenon.