Relation between Dispersion Characteristics over Surfaces with Dissimilar Roughness and Atmospheric Stability, under Conditions of Equal Geostrophic Winds

A simple model was described that related the dispersion of material from ground-level sources at 2 areas, taking into account dissimilarities in the surface roughness parameter (z0) and the atmospheric stability characterized by the Monin-Obukhov length (L). The geostrophic wind speed was assumed constant and equal at the 2 areas and was used to interrelate the wind conditions. The ratio of the crosswind-integrated concentrations at a given downwind distance depended on 4 dimensionless parameters; z0/L and .hivin.z/L for the 2 areas in question. Here .hivin.z was the mean height of particles that travelled a distance x; .hivin.z/L was found when z0/L and x/z0 were known. The model was reduced to 3 dimensionless parameters by merging .hivin.z/L for the 2 areas into a composite parameter. Dimensionless results from the model were illustrated for discrete values of this composite parameter.