TRIAL OF A NONLINEAR DIFFUSION EQUATION AS A MODEL OF TURBULENT-DIFFUSION

A nonlinear diffusion equation is demonstrated as a model of turbulent dispersion in the atmosphere. It is based on a similarity solution fo r two-dimensional dispersion (longitudinal advection and vertical diff usion) from a horizontal line source. The coefficient for the vertical diffusion is a nonlinear function of both concentration and height. T he similarity solution for two-dimensional dispersion includes a beta function with arguments that are functions of the parameters for the w ind profile and the nonlinear vertical diffusion. The solution is succ essfully fitted to two sets of Prairie Grass data.