A numerical method for simulation of convective plume field dispersion.

Abstract

In simulating dispersion in complex situations a simple description of the unresolved motions in terms of a spectrum function and velocity distribution may become insufficient because information on relative phases of different spectral commponents is ignored. This phase information may be retained most directly by explicit generation of winds given by a model of the significant, but unresolved, systems. An example of such a system, the convective plumes of the unstable boundary layer, is considered. 
The results show that some of the qualitative aspects of dispersion found in a physical simulation of the unstable planetary boundary layer, which can not be explained by a rational application of the eddy diffusivity approach, can be explained by employing the Monte-Carlo approach. A more complete understanding of the physical nature of convective plume field is needed before quantitative agreement can be expected.