An Analysis of Monthly Mean Wind Stress Over the Global Ocean

Abstract

The monthly wind stress over the global ocean has been calculated using updated climatological monthly mean wind data. The effect of the variablility of the wind has been incorporated by using the wind speed frequency estimated from the observed mean and variance in a Gaussian distribution model. The spatial and temporal data gaps in the high-latitude oceans have been filled with surface winds estimated from the monthly mean geostrophic winds. The calculated stress data have revealed a number of interesting features that were not well resolved in earlier studies. A rapid transition from a winter to summer stress pattern in the north Indian Ocean is especially notable, and large-scale gyral patterns in the Antarctic Ocean and their seasonal variations are now well-defined. The monthly wind-stress curl calculated from the present stress data is in good agreement with earlier calculations, although the present curl field reveals a more detailed structure, especially in high latitudes and in the tropics. These data should prove useful in global ocean general circulation models, as well as in other theoretical studies of ocean transports. They should also be useful in atmospheric general circulation studies, in view of their crucial importance to the atmospheric angular momentum balance.