Modification of Surface Fluxes from Component Models in Global Coupled Models

Abstract

Abstract The present generation of global coupled ocean–atmosphere GCMs contains considerable systematic errors both in terms of net surface heat flux and simulated SSTs. Here, a global coupled GCM is used to illustrate how systematic errors in the separate coupled model components (atmosphere and ocean) contribute to the simulations of net surface heat flux and SST when the components are coupled together. Features of the coupled model simulation are a combination of errors in the component models and errors introduced due to the dynamic interaction, both local and nonlocal, between atmosphere and ocean. Various regions and latitudinal zones are examined to determine the processes that produce the net surface heat fluxes and SSTs in the coupled simulation. In the coupled model, a good simulation of net surface heat flux does not always produce a correspondingly accurate simulation of SST. Alterations of surface winds and/or ocean currents can introduce SST errors and consequent compensating surface fluxe...