Oceanic responses to gradual transitions of equator-to-pole temperature-gradients

Responses of an ocean model to gradual transitions of equator-to-pole gradients show that several quasiequilibrium states within the thermally driven regime are generated under identical forcing conditions. These different states are associated with different patterns (the location and the penetration depth) of oceanic convection. Small changes in the thermal forcing conditions can push the system into an oscillatory regime. Once in this regime, oscillations appear to proceed as internal processes. One important implication of these results is that the presentday ocean climate may not recover fully if the atmospheric COz level, after doubling, is lowered to the present-day level.