Daytime Temperature Profiles

Abstract

An equation for the daytime lapse rate of temperature as a function of z/L is derived assuming the lapse rate varies as z?? in very light winds. This variation is presumed to result from the geometry of buoyant plumes. The equation, which agrees very well with some data taken by Dyer, predicts a maximum value for the lapse rate at a fixed height and with given heat flux, at intermediate values of z/L. This variation suggests the concept of eddy viscosity as usually applied does not adequately describe the heat flux in unstable conditions.