Gulf Stream forcing of the winter North Atlantic oscillation

Using observational datasets and coupled model simulations, it is shown that a surface heat flux pattern associated with Gulf Stream variability plays a role in forcing the winter North Atlantic oscillation. It is suggested that by monitoring the Gulf Stream, it may be possible to produce a useful long‐range NAO forecast. By analysing surface heat flux patterns rather than sea‐surface temperatures (as used in previous studies), we find agreement between observational and model‐based results. The results suggest that there may be systematic errors in the modelled surface heat‐flux sensitivity to SST anomalies but that the modelled atmosphere tends to respond correctly to the heat fluxes it is ‘given’. Copyright © 2004 Published by Elsevier Ltd on behalf of Royal Meteorological Society.