The currents and circulation in Saldanha Bay after 1975 deduced from historical measurements of drogues

Abstract

In 1975, major harbour works modified the physiography of Saldanha Bay, dividing it into two bodies of water, Big Bay and Small Bay. This study uses historical drogue data to investigate the relative importance of physical forcing mechanisms (wind and tides) in Saldanha Bay after 1975. It is concluded that wind-forcing is the dominant factor in determining current direction and magnitude in both Small Bay and Big Bay. The dominance of the wind is in the surface layer which, in summer, is above the thermocline and, in winter, extends throughout the water column.