Some Results of Direct Measurements of Momentum Flux in the Atmospheric Boundary Layer by Sonic Anemometer

Abstract

The results of direct measurement of vertical eddy transport of momentum near the ground by the use of sonic anemometers are discussed. Measurements were made at the heights from 1.5 to 3.0m above the ground together with surface drag force measurements by a specially designed drag-meter. The magnitude of directly measured momentum flux varies with height and is larger than that expected from the surface drag force. The existence of abrupt momentum release of short duration in the airflow with large shear was also found.