Effect of Radiative Heat Transfer on Profiles of Wind, Temperature and Water Vapor in the Atmospheric Boundary Layer

Abstract

The diurnal changes of wind, air temperature, and water vapor profiles near the ground have been investigated by integrating numerically the diff erential equations of momentum, heat and vapor transfers. The equation for change of air temperature includes the long-wave radiative heat transfer. Equality of the diffusivities for momentum, heat and vapor transfers is assumed. Profiles obtained deviate from the theoretical profiles which exclude the long-wave radiative heat transfer, and assume the steady state. In the stable case, the deviation of estimated wind velocity is relatively small and that of air temperature is somewhat larger, and the largest dis- crepancy is seen in the profile of water vapor. In unstable cases, the so-called constant-flux layer is at the heights of several tens of meters, but in stable cases, it is about several meters high. In the daytime at the height of several centimeters, there is a layer of intense heating due to radiative flux divergence. It appears that such excess rate of heating might yield the heat energy of convective mixing. In the nighttime, radiation fog started to form in a layer about 0.1 to 1m high from the surface, and the layer, after spreading slowly upwards, finally disappeared after sunrise.