INFLUENCE OF WIND SHEAR ON LATERAL PLUME DISPERSION AT LARGE DISTANCES FROM THE SOURCE

S. P. Beschastnov

Lateral pollutant dispersion in the initial segment of a gas-aerosol plume is governed by turbulent diffusion, while at large distances from the source it is affected by lateral wind shears. By comparing absolute lateral dispersions calculated from a Monte Carlo diffusion model and empirical formulas, it is shown that the influence of lateral wind shears is well overestimated and the coefficient of proportionality in the shear term should be decreased from 2/3 to 0.06. This value is close to Pasquill's estimate obtained from experimental data. As input information the calculations use data of atmospheric radiosounding at aerological stations Batumi and Krivoi Rog with different orographic conditions and different types of underlying surface.