Experiments with a global ocean model driven by observed atmospheric forcing

Abstract A global ocean model with a 5° horizontal grid size, previously used in the coupled climate model of Washington et al. (1980), is used here with observed monthly mean wind stress and atmospheric temperatures for the purposes of varying model parameters to suggest values for future coupled climate model experiments, and examining heat storage and transport in the model ocean. A control run is carried out with the same internal parameters as in the climate simulation of Washington et al. (1980). Observed atmospheric forcing produces an oceanic circulation closer to the observed than in the coupled climate model. Necessarily large horizontal momentum diffusion leads to weak zonal currents in both cases; however, the stronger observed wind stresses in the decoupled model produce more vigorous and more realistic meridional ocean currents. Three additional ocean experiments test parameter variations. Lowering horizontal heat diffusion increases north-south temperature gradients and intensifies ocean ci...