%0 Book Section
%9 OS CH : Chapitres d'ouvrages scientifiques
%A Servain, Jacques
%A Wainer, I.
%A Dessier, Alain
%A McCreary, J.P.
%T Modes of climatic variability in the tropical Atlantic
%B Water resources variability in Africa during the 20th century = Variabilité des ressources en eau en Afrique au 20ème siècle
%C Wallingford
%D 1998
%E Servat, Eric
%E Hughes, D.
%E Fritsch, Jean-Marie
%E Hulme, Mike
%L fdi:010017928
%G ENG
%I AISH
%@ 1-901502-65-1
%K CLIMATOLOGIE ; INTERACTION OCEAN ATMOSPHERE ; VARIATION INTERANNUELLE ; TEMPERATURE DE SURFACE ; VENT ; ANOMALIE ; ZONE DE CONVERGENCE INTERTROPICALE ; MODELISATION
%K ATLANTIQUE TROPICAL
%N 252
%P 45-54
%U https://www.documentation.ird.fr/hor/fdi:010017928
%> https://horizon.documentation.ird.fr/exl-doc/pleins_textes/divers09-04/010017928.pdf
%W Horizon (IRD)
%X The tropical Atlantic Ocean exhibits two primary modes of interannual climate variability : an "equatorial mode" analogous to, but weaker than, the Pacific El Nino phenomenon, and a "dipole" mode that does not have a Pacific counterpart. The equatorial mode is responsible for warm (and cold) sea surface temperature (SST) events in the Gulf of Guinea, and is identifiable with changes in the equatorial thermocline slope resulting from zonal-wind anomalies in the western tropical Atlantic. The dipole mode is characterised by SST anomalies of opposite sign on either side of the mean position of the Intertropical Convergence Zone (ITCZ). To date, the dipole mode has been detected in the ocean only from SST. Here it is shown, using surface and subsurface oceanic temperatures obtained from observations as well as from a numerical solution, that the dipole mode is linked to changes in the equatorial thermocline slope occurring at interannual time scales. Thus, the two main interannual climatic modes appear to be dynamically linked in this frequency band. Futhermore, the dominant pattern of variability in both modes involves North-South displacements of the ITCZ, as in the annual response. (Résumé d'auteur)
%S Publication - AISH
%B Water Resources Variability in Africa during the 20th Century : International Conference
%8 1998/11/16-19
%$ 032CLIMET ; 021CLIMAT