The Coriolis Force in Relation to the Sea and Land Breezes—A Historical Note

Abstract

The deflecting effect of the earth's rotation on winds has been known since the writings of Hadley in 1735, and observations of the clockwise diurnal directional turning of the sea and land breezes in the Northern Hemisphere have been published in quantity since 1801. But, the first reference associating the turning with the earth rotation through the latter's deflecting effect appears to have been made by the Austrian meteorologist and climatologist von Hann in 1901. Jeffreys' (1922) conclusion that the earth's rotation is not relevant to the dynamics of the sea and land breezes, was based on an overestimate of the speed and an excessive underestimate of the landward penetration of the sea breezes. In 1934 Brunt suggested that the Earth's rotation may be important. Neither Jeffreys nor Brunt seem to have been aware of yon Hann's statement and examples. Haurwitz (1947) was the first to show dynamically that the Coriolis force can explain the observed diurnal directional turning of the sea and land breezes. Neumann (1977) emphasizes that the observed rate of rotation of direction is not constant over the diurnal cycle, as it should be if only the Earth's rotation were operative; the interaction of the pressure-gradient and frictional forces with the flow has a modulating effect on the rate due solely to the Coriolis force. Kusuda and Alpert (1983) study the dynamics of cases where the directional turning is counterclockwise in the Northern Hemisphere.