TECHNIQUES FOR ASYNCHRONOUS AND PERIODICALLY SYNCHRONOUS COUPLING OF ATMOSPHERE AND OCEAN MODELS .2. IMPACT OF VARIABILITY

A periodically synchronous scheme suitable for coupling atmosphere and ocean models with high internal variability is presented. The perform ance of the scheme is tested by means of a simple zero-dimensional non -linear energy balance model with stochastic forcing. The equilibrium behaviour and the response to changes in the model parameters are anal ysed. The response experiments are similar to CO2 doubling and transie nt CO2 experiments. The best results are obtained using a method with weighted means of the air-sea fluxes which are calculated during the s ynchronously coupled periods.