| Description |
The Guinea Current LME extends from the Bissagos Islands in Guinea-Bissau to Angola. Shelf waters are composed of two subsystems; one is marked by thermal stability, and the other by instability of its waters. Processes affecting the functioning of these two subsystems are quite different. The Gulf of Guinea upwelling system differs from eastern boundary current systems due to its proximity to the equator and its seasonal functioning. The Guinea Current is an eastward, superficial flow, extending to depths of 15-25 meters, that is fed by the North Equatorial Counter Current (NECC) off the Liberian coast. It overlays the Guinea Under Current (GUC), which flows westward from the Bight of Biafra, as a return branch of the Equatorial Under Current (EUC).
The Inter-Tropical Convergence Zone (ITCZ) is a rain-generating zone of instability on the northern coast of the Gulf of Guinea, which separates northern trade winds and dry, continental, heavy air masses from wet, maritime, lighter, southern trade winds. Its migration generates seasons and thus influences riverine input from seasonal monsoons to the relatively warm coastal Tropical Surface Waters along the coast. Salinity in the TSW varies due to riverine input during the wet monsoon, with small rivers flowing in June when the ITCZ migrates north, and flooding from the Sudanian Rivers in September to November, when the ITCZ migrates south. Seasonal upwelling occurs from June to late September between Cape Palmas and Cotonou-Lagos, limited at each end by the influx of warm, low-salinity waters originating from the Bight of Biafra and off the Guinea coast. (Berrit, 1961, 1962a, 1962b, 1966) (http://www.na.nmfs.gov/lme/text/lme28.htm) |
