On the North Atlantic Ocean heat content change between 1955-70 and 1980-95

The upper-ocean heat content of the North Atlantic has undergone significant changes over the last 50 years but the underlying physical mechanisms are not yet well understood. In the present study, the authors examine the North Atlantic ocean heat content change in the upper 700 m between the 1955-70 and 1980-95 periods. Consistent with previous studies, the large-scale pattern consists of warming of the tropics and subtropics and cooling of the subpolar ocean. However, this study finds that the most significant heat content change in the NorthAtlantic during these two time periods is the warming of theGulf Streamregion. Numerical experiments strongly suggest that this warming in theGulf Streamregion is largely driven by changes of the large-scale wind forcing. Furthermore, the increased ocean heat content in theGulf Streamregion appears to feedback on to the atmosphere, resulting in warmer surface air temperature and enhanced precipitation there. © 2012 American Meteorological Society.