The Role of the Atlantic Ocean in Climate Forecasting

We discuss evidence from observations and atmosphere model studies concerning the influence of Atlantic Ocean conditions on winter climate in the North Atlantic / European region. Both sources of evidence suggest the Atlantic influence is significant, and that the atmospheric response to Atlantic variability projects on the North Atlantic Oscillation pattern. It is suggested that the mechanism involves the impact on local convection of SST anomalies in the tropical Atlantic region, and the consequent excitation of a Rossby wave response that propagates into midlatitudes. There is now an important need to investigate the relevance of these results to coupled model based seasonal and longer term climate forecasts.