The Determination of the von Karman Constant

Abstract

From simultaneous measurements of the friction velocity u*(=√-uw) and the mean wind profile in the atmospheric surface layer, the von Karman constant was determined to be 0.39. The constant is not a fixed value but has a range with a standard deviation of about 7%. This property may be inherent in the nature of the atmospheric turbulence. Before the field observations, the aerodynamic characteristics of the sonic and cup anemometers were examined. In determining the present von Karman constant, errors due to these characteristics were corrected.