Study of atmospheric dispersion of pollutant plumes from elevated stacks assuming a finite limit to the rate of vertical dispersion

In this paper, we investigate the atmospheric application of Moninʹs equations for the probability density functions (pdf) for the vertical position of particles diffusing in a turbulent flow with a finite diffusion speed as opposed to the infinite speed inherent in the parabolic diffusion equation and the Gaussian distributions of plumes. Moninʹs equations are modified for the case of particle dispersion in a convective boundary layer where the vertical distribution is asymmetrical. We also provide an analytical solution of the pdf of vertical dispersion applicable to this case of asymmetrical vertical distribution by making some suitable assumptions on the nature of turbulence. Vertical concentration profiles for particles emitted from stacks of various heights inside a convective boundary layer are compared with laboratory measurements. The agreement between predicted and observed concentration profiles is shown to be good.