Poleward heat transport by the atmosphere and the oceans regulates the earth's climate by cooling the tropics and warming the poles. Observations suggest that about half of the total transport is acc0mplished by the atmosphere and half by the ocean. In this project we investigated the partitioning of poleward heat transport between the atmospheric and oceanic components in coupled numerical models. Uncoupled versions of the models were also used to estimate the intrinsic sensitivity of the heat transport in each component separately.

Following are the principal results obtained:
- Large scale air-sea interaction in mid-latitudes is dominated by the atmospheric forcing of the ocean (rather than vice versa, as in the tropics). Characteristic patterns of the mid-latitude air-sea interaction can be explained by the systematic changes in the strength of the prevailing surface winds.
-Stronger surface winds take heat from the ocean mixed layer, but also deepens it, and the net effect is to warm the full ocean column. A 20% increase in surface wind speed has the same effect on the oceanic heat storage as a 1.7⁰C increase in surface air temperature.
-In the atmospheric model, many different combinations of vertical and meridional temperature gradients support the same meridonal heat transports. The emergence of a unique climate in equilibrium with particular external forcing can be extremely slow taking 5 or more years.
- In a hierarchy of coupled models, we consistently found that when the external atmospheric) forcing was varied, about 80% of the required change in heat transport was accomplished by the atmosphere, and about 20% by the ocean.