Seasonal variability of the global ocean wind and wave climate

Abstract

A data set spanning a period of 10 years and obtained from a combination of satellite remote sensing and model predictions is used to construct a global climatology of ocean wind and wave conditions. Results are presented for: significant wave height, peak and mean wave period and wave direction as well as wind speed and direction. The results are presented in terms of mean monthly statistics. The processed data set provides global resolution of 2°. The climatology clearly shows the zonal variation in both wind speed and wave height, with extreme conditions occurring at high latitudes. The important role played by the intense wave generation systems of the Southern Ocean is clear. Swell generated from storms in the Southern Ocean penetrates throughout the Indian, South Pacific and South Atlantic Oceans. During the Southern Hemisphere winter, this swell even penetrates into the North Pacific. The results confirm visual observations that the Southern Ocean is consistently the roughest ocean on earth. It is shown, however, that this is mainly caused by consistent high wind speeds, rather than the extended westerly fetch which exists. The west coasts of most continents have noticeably rougher wave climates than their respective east coasts, as a result of the longer generation fetches which exist on the west coasts. Copyright © 1999 Royal Meteorological Society