Impact of an Eddy-Permitting Ocean Resolution on Control and Climate Change Simulations with a Global Coupled GCM

Abstract

Abstract Initial results are presented from a 150-yr control and an 80-yr transient simulation of a new global coupled climate model with an ocean model resolution of ⅓°, which is sufficient to permit ocean eddies to form. With no spinup procedure or flux correction, the coupled model remains close to radiative equilibrium, and the enhanced ocean resolution allows an improved ocean state to be simulated; this includes a general decrease in sea surface temperature errors compared to climatology and more realistic large-scale flows compared to previous lower-resolution models. However, the improvements in the atmospheric and coupled model climatology are less pronounced, with small improvements in atmospheric circulation counterbalanced by an El Nino–Southern Oscillation cycle that has peak power at too short a period and with too little power on longer time scales. With the model using exactly the same atmospheric component as a lower-resolution counterpart, the comparison gives some insight into the impac...