Scaling of the Atlantic meridional overturning circulation in a global ocean model

Abstract

Using a global ocean model, we revisit the issue of the scaling of the Atlantic Meridional Overturning Circulation (AMOC) versus the vertical diffusivity. With a continuation approach, we are able to compute curves of exact steady solutions of the global model versus the magnitude of the vertical diffusivity K_V in the model; we find that the AMOC strength scales as K^1/3_V. This result is analysed with help of the local density balances in the Atlantic and Pacific. It appears that processes in the Pacific are crucial for the scaling behaviour of the AMOC.