PHYSICAL FORCING AND CIRCULATION PATTERNS ON THE AGULHAS-BANK

Physical forcing factors and their influence on the oceanography and c irculation patterns of the Agulhas Bank are reviewed. The former inclu de the Agulhas Current and its inshore features, the prevailing wind f ield (and its relation to coastline orientation), coastally trapped wa ves and the effect of seasonally varying insolation. Two aspects of th e oceanography of the Agulhas Bank, namely, the occurrence of a 'ridge ' of cool water on the eastern and central Bank, and the exchange of w ater between the central and western Bank are singled out for specific attention and data from 1987 to 1992 are presented. These data, which were mostly collected in November and therefore represent spring/summ er conditions, include subsurface thermal sections and direct current measurements made by means of a ship-bourne acoustic doppler current p rofiler. Our conclusions can be summarized as follows: The oceanograph y of the eastern Bank is dominated by windforcing and the position and orientation of the inshore margin of the Agulhas Current. On the cent ral Bank the cool-water ridge, present in four out of five rears' surv eys as a shallow but mainly subsurface feature of variable width, was found to separate the outer Bank region influenced by intrusions of Ag ulhas Current water and shelf-edge upwelling, from a region of deep mi xing inshore to the west. Flow patterns appear complex, with both reci rculation to the east and avenues for transport to the west. Previous findings concerning the hydrology of the western Bank are supported.