Northwest Africa upwelling and the Atlantic climate variability

Summer Subtropical North Atlantic (SNA) Sea Surface Temperature (SST) anomalies have recently been connected to winter atmospheric variability in the Atlantic European sector. Wind-induced surface heat flux changes are believed to be the major cause of SNA SST anomalies. However, the impact of coastal upwelling off northwest Africa, on SNA SST variability has been overlooked. Since the area is known to have a richer dynamical behavior than other regions of the central SNA, subsurface thermal anomalies are included in our analysis. Results show that this upwelling region affects significantly the patterns of covariability between climatically relevant variables, suggesting that more intricate processes may be involved in generating surface anomalies that, in turn, may influence the European sector climate variability. Copyright 2005 by the American Geophysical Union.