A new parameterization of eddies in a coarse resolution ocean model yi
elds deep ocean salinities and temperatures that are significantly clo
ser to observations than with previous parameterizations. This is achi
eved because dense water is able to flow over sills and into the deep
ocean without being diluted with the surrounding water. In addition, t
he depth to which surface-induced tracers penetrate in the Southern Oc
ean is now realistic. This depth is overestimated by previous ocean mo
dels, including those used to estimate global warming. Adding the new
eddy parameterizaton to coupled atmosphere-ocean models is expected to
yield greater global warming.