Robustness of multiple equilibria in the global ocean circulation

Abstract

In an idealized Atlantic-Pacific ocean model we study the steady state solutions versus freshwater input in the northern North Atlantic. We find that four different states, the Conveyor (C), the Southern Sinking (SS), the Northern Sinking (NS) and the Inverse Conveyor (IC), appear as two disconnected branches of solutions, where the C is connected with the SS and the NS with the IC. We argue that the latter has the intriguing consequence that the parameter volume for which multiple steady states exist is greatly increased.