Articles scientifiques
P. Hughes and E.D. Barton (1974)
Stratification and water mass structure in the upwelling area off northwest Africa in April/May 1969
Deep Sea Research and Oceanographic Abstracts, 21(8):611-628.
A study of the temperature and salinity in the upwelling region between the Canary Islands and Cap Vert was made on Discovery Cruise 26 (April/May, 1969). Relative to offshore conditions cold surface water was present near the coast throughout most of the area surveyed. Upwelling appeared to be most intense off Cap Blanc and Cabo Bojador. A water mass analysis showed that near Cap Blanc there was a fairly rapid transition in the upper layer from North Atlantic Central Water to water having the lower salinity characteristics of South Atlantic Central Water. Surface observations showed a similar division, confirming that longshore gradients of the water properties in the area of the cape are not negligible, and that there is a separate southern circulation. A further division of the upper layer water masses was present at depths shallower than 300 m at several inshore stations on the three most southerly sections and seems to idicate that there was a northward transport near the coast originating sputh of Cap Vert. The available evidence further seems to indicate that a fairly narrow northward subsurface flow, centred at approximately 250 m on the potential density surface δθ = 26·8 is present over the continental slope from Cap Vert to Cabo Bojador and is nowhere wider than 60 nautical miles (1 nautical mile = 1·852 km). South of Cap Blanc the indercurrent is part of the general northward transport in the layers above 300 m, but north of Cap Blanc it is confined to a subsurface layer below the prevailing southwesterly drift.
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