Secular Change in Reported Surface Wind Speeds over the Ocean

The Comprehensive Ocean-Atmosphere Data Set reveals that mean scalar winds decreased between 1854 and 1920 and increased since World War II. The latter increase is due to a change in estimating procedure and to the growing proportion of ships equipped with anemometers. The sign of the earlier decrease is attributed to the transition from sail to steam; although a true secular trend might also contribute, it cannot be isolated.