INVESTIGATION OF THE INTERANNUAL VARIABILITY OF THE TROPICAL ATLANTIC OCEAN FROM SATELLITE DATA

摘要

The interannual variability of the tropical Atlantic Oceanrnis analyzed with series of altimetric dynamic topographyrndata, sea surface temperatures, and wind stress betweenrnOcotobre 1992 and January 2011 using EmpiricalrnOrthogonal Functions and Singular ValuernDecompositions. Three regions of maximum variabilityrnare evidenced: a northern one, between 10 and 20°N,rnwhere altimetry, sea surface temperature and wind stressrnare strongly connected through thermosteric and Ekmanrnpumping effects in 2010 but also in 1998 and in 2005; Arnsouthern region, along 20°S, where dynamic topographyrndecreases in 1997 and in 2010 in agreement with surfacerncooling and southern tradewinds intensification; Anrnequatorial region whose variability appears either as anrnEst-West slope of the topography and temperature allrnalong the equator (2005 and 2010) or as a (cold) tonguernin the Gulf of Guinea (1997 and 2002). Both local windrn(meridional component) and western remote (zonalrncomponent) effects can be involved in this oceanicrntriggering. First results of the teleconnections betweenrnthis tropical Atlantic interannual variability and therntropical Pacific El Ni?o–Southern Oscillation indicate arnpossible connection of the tropical Atlantic between 10-rn20°N with a 19 weeks delay, and in the Gulf of Guinearnwith a 70-80 weeks one.