A laboratory model of diffusion into the convective planetary boundary layer

摘要: A laboratory model of the convective planetary boundary layer has provided information concerning evolution concentration distributions downwind from a simulated continuous point source located near ground. Results indicate that Gaussian plume formulation adequately describes γ-concentration distributions, but is useful in predicting z-concentration only to distance downstream about x = 0.5zi/(w*/U), where zi mixed depth and w*/U dimensionless stability parameter. Near this an elevated maximum appears at height above release height. The rises 0.8zi 1.7zi/(w*/U) retains its identity until pollutants become vertically well farther downstream. Use parameter permits results be applied range atmospheric conditions encompassing Pasquill-Gifford classes B. Close agreement found between data observations ground-level lateral spread Islitzer (1961) Dumbauld (1963), latter measurements extended out x≃ 3 km.