Wind Distribution Asymmetry in the Lowest 90 Meters and Its Effect on Diffusion

Abstract

For many applications it is assumed that the turbulent fluctuations of the wind components are normally distributed. The validity of this assumption was examined for the first 90 m of the atmosphere by observing the skewness of the wind component distribution as related to atmospheric stability and height above the ground. Results of this study show that the skewness of the longitudinal and vertical components of the wind are indeed functions of atmospheric stability and height above the ground. The skewness of the frequency distribution of the longitudinal component tends to increase with increasing stability and to decrease algebraically from one level to the next higher level, whereas the vertical component varies inversely with the stability and directly with height.