The exponential wind profile

Abstract From a definition and a hypothesis the form of the wind profile in the turbulent boundary layer when the air is thermally stratified is derived as magnified image . This solution is expected to be applicable in all stabilities and to all heights below which the shearing stress and the vertical heat flux remain constant. A critical examination of the experimental procedure necessary to test the validity of this, or of any, formulation for the steady‐state wind profile leads to a specification which the observational site and the weather conditions should meet. The results of a series of experiments are presented and analysed. These comprise measurements of wind speed and temperature at a number of levels up to 16 metres, supplemented by observations of net radiation, heat flux into the air and into the ground, and shearing stress. the analysis affords good verification of the form proposed for the wind profile. A variety of evidence is adduced to show that buoyancy modifies the transfer of heat more strongly than that of momentum, and that the discrimination increases with height above the surface.