Wind profiles in and above a forest canopy

Abstract

Abstract Using an on‐line computer, measurements were made of wind speeds in and above a pine forest together with accurate potential temperature profiles over a wide range of stability conditions. It was found that between values of Richardson number of approximately –0.05 and +0.10 the wind profile above the canopy followed a pure log form with the measured roughness length increasing linearly from 0.75 to 1.23 m respectively. Outside this stability range a log‐linear profile could be fitted. The shape of the wind profile within the canopy was determined, and an increase of wind speed within the trunk space was noted. A preliminary experiment to determine the effect of the anemometer tower structure upon wind speed readings is also described.