Influence of the Gulf of Guinea Coastal and Equatorial Upwellings on the Precipitations along its Northern Coasts during the Boreal Summer Period

K. E. Ali , K. Y. Kouadio , E.-P. Zahiri (1) , Angora Aman , A. P. Assamoi , Bernard Bourlès (2)

1 IRD - Institut de Recherche pour le Développement
2 OLVAC - Océan du Large et Variabilité Climatique

The Gulf of Guinea (GG) is an area where a seasonal upwelling takes place, along the equator and its northern coasts between Benin and Cote d'Ivoire. The coastal upwelling has a real impact on the local yet documented biological resources. However, climatic impact studies of this seasonal upwelling are paradoxically very rare and disseminated and this impact is still little known, especially on the potential part played by the upwelling onset on the regional precipitation in early boreal summer. This study shows that coastal precipitations of the July-September period are correlated by both the coastal and equatorial sea-surface temperatures (SSTS). This correlation results in a decrease or a rise of rainfall when the SSTs are abnormally cold or warm respectively. The coastal areas that are more subject to coastal and equatorial SSTs influence are located around the Cape Three Points, where the coastal upwelling exhibits the maximum of amplitude.

Domaines: Océan, Atmosphère

K. E. Ali, K. Y. Kouadio, E.-P. Zahiri, Angora Aman, A. P. Assamoi, et al.. Influence of the Gulf of Guinea Coastal and Equatorial Upwellings on the Precipitations along its Northern Coasts during the Boreal Summer Period. Asian Journal of Applied Sciences, 2011, 4 (3), pp.271-285. ⟨10.3923/ajaps.2011.271.285⟩. ⟨hal-00605937⟩