|The influence of the Agulhas Current on the adjacent coastal ocean: possible impacts of climate change|
|Lutjeharms, J.R.E.; de Ruijter, W.P.M. (1996). The influence of the Agulhas Current on the adjacent coastal ocean: possible impacts of climate change. The coastal ocean in a global change perspective 7(Special Issue 2-4): 321-336|
|In: Djenidi, S. (Ed.) (1996). The coastal ocean in a global change perspective. Journal of Marine Systems, 7(Special Issue 2-4). Elsevier: Amsterdam. 117-438 pp., more|
|In: Journal of Marine Systems. Elsevier: Amsterdam. ISSN 0924-7963, more|
The dynamics of the coastal ocean along the southeastern coast of Africa is dominated by a strong and intense western boundary current, the Agulhas Current. With a near-uniform, narrow continental shelf and a steep shelf slope that stabilizes this current, the trajectory of the Agulhas exhibits great stability. The only substantial perturbation occurs with the irregular passage of a Natal Pulse, a soliton meander. The initiation of this meander at the Natal Bight is due to a barotropic instability when the intensity of the landward border of the current exceeds a certain threshold value. This may come about with natural fluctuations in the current or with the adsorption of deep-sea eddies onto the current. Under a climate change scenario of altered wind stress curl over the South Indian Ocean it is conceivable that the threshold for the triggering of a Natal Pulse will occur more frequently. This will lead to a situation where the current axis on average lies further offshore. The possible consequences of such a situation on the rainfall of the coast, on the ecology of estuaries and the coastal ocean, and on the socio-economics of the region is discussed.