SENSITIVITY OF A COUPLED OCEAN-ATMOSPHERE MODEL TO PHYSICAL PARAMETERIZATIONS

The sensitivity of a coupled ocean-atmosphere general circulation mode l to parameterizations of selected physical processes is studied. The parameterizations include those of longwave radiation and surface turb ulent fluxes in the atmospheric model, and those of vertical turbulent mixing and penetration of solar radiation in the ocean model. It is s hown that the performance of the coupled model is highly sensitive to the parameterization of longwave radiation. This sensitivity is not so lely due to the difference in surface radiative flux but involves inte ractions among radiation, convection, and large-scale dynamics of the atmosphere and ocean. It is concluded that differences in parameteriza tions can have large impacts on the performance of the coupled model, and these impacts can be very different from what may be expected from uncoupled model simulations.