Non-local turbulent transport: pollution dispersion aspects of coherent structure of convective flows

Abstract

During the last forty years vertical exchange in the atmospheric surface layer has been parameterized with the aid of the Monin-Obukhov similarity theory. Currently it is understood that the concept of local flux-gradient correspondence underlying that theory and most traditional turbulence closures breaks down in convective conditions. In the present paper a review of the problem is given, and a new theoretical model is proposed capable of reproducing the essential features of convection. The model is verified using data from recent large-eddy simulation of convective boundary layers together with the reference atmospheric data. Recommendations are given as to the process of practical parameterization of the surface fluxes and horizontal velocity variances in pollution dispersion models.