The Canadian Climate Centre Second-Generation General Circulation Model and Its Equilibrium Climate

Abstract

The Canadian Climate Centre second generation general circulation model (GCMII) is described. The description emphasizes aspects in which the new model differs from the 1984 model (GCMI) as described by Boer and collaborators. Important features of the new version include an interactive cloudiness parameterization, improved solar and terrestrial radiative beating calculations, a more sophisticated treatment of land surface processes, and a simple ocean mixed-layer model with a thermodynamic sea ice component. Results from a ten-year climate simulation made with the new model are presented and compared with observed climatology. The comparison is made for the December-February and June-August periods. The model reproduces the observed climatology in a generally successful manner.