The south Atlantic water bodies which have a vertical layer of 30 to 40 m coming from the equatorial counter current, sometimes called Guinean waters, reach their northern border (20°50’N) during the hot season. These waters are hot (26.8 - 28.8°C) and relatively less salty (34.00 - 35.5 psu) because of the flow of African continental waters (Debravolskya 1964 ; Manriques and Fraga 1982). They alternate seasonally with the North Atlantic surface water bodies, which occupy the northern part of the region and a layer from the surface to depths of 100 to 150m (to 100 - 150m deep). These water bodies are formed by the southern branch of the Canary current. They undergo considerable special transformations which are conditioned by the influence of the atmosphere. They are characterized by cold waters (16 - 24°C) and relatively salty (35.9 - 36.70 psu; Fraga F. 1973).

 


Thermal Front