Multiple equilibria of an asymmetric two-basin ocean model

Abstract

An ocean general circulation model is used to examine the role of model geometry and surface buoyancy and wind stress forcing in the asymmetry of the global thermohaline circulation. The model domain is a highly idealized Atlantic and Pacific, linked by a circumpolar ocean in the south, and the integrations are performed under mixed boundary conditions diagnosed from spinups under various temperature and salinity profiles constructed from the present-day climatology. The model exhibits a tendency to favor either a "conveyor'-type circulation with sinking in the northern North Atlantic and upwelling in the North Pacific, or a "southern sinking' state with deep sinking in the Antarctic only. -from Authors