Evaluation of the North Atlantic SST forcing on the European and Northern African winter climate

Abstract

The 1960–1996 patterns of monthly anomalous winter precipitation in Europe and North Africa (ENA) and their connection with the North Atlantic SST are studied. A lag Singular Value Decomposition analysis has been applied to monthly SST and precipitation data to define the most influential Atlantic oceanic areas on the winter ENA rainfall. The results indicate a link between the subtropical North Atlantic SST and the winter precipitation anomalies in areas of the northern–southwestern Europe and northern Africa, since the preceding summer months. We also show that the SLP pattern connected with this subtropical oceanic area is not the NAO itself, and we explain this subtropical–extratropical connection through changes in the trade winds. The estimates of ENA winter precipitation anomalies, based on the previous summer SST, have been validated using a bootstrap analysis. Finally, we verify the reliability of this connection for the whole period from 1900 to 1996. Copyright © 2006 Royal Meteorological Society.