The Atlantic Meridional Overturning Circulation (AMOC) - colloquially known as "Gulf Stream" - transports warm surface waters into the high latitudes, where they cool, sink and return southwards at depth as cold North Atlantic Deep Water. Variations in AMOC can significantly affect the northward ocean heat transport and therefore the European and North Atlantic climate. Through its influence on sea surface temperature (SST), AMOC can further impact climate phenomena such as Sahel droughts in Africa or the frequency of Atlantic hurricanes. Therefore, it is of outmost importance to be able to predict these climate variations on a time horizon from years to decades. Multi-year climate predictions have so far been limited to predicting surface temperature variations and hurricane frequency, but have not addressed the prediction of any dynamical quantity such as the AMOC.
See more information in the press release: link
Matei, D., J. Baehr, J.H. Jungclaus, H. Haak, W. A. Müller und J. Marotzke: Multi-year prediction of the Atlantic Meridional Overturning Circulation at 26.5°N. Science, 2012, in press.