Diffusion from a line source in an urban atmosphere

Abstract A model for the diffusion of material from a line source in an urban atmosphere is presented. The plume is assumed to have a well-defined edge at which the concentration falls to zero. The vertical wind shear is accounted for by using a power law, the exponent of which is explicitly determinable as a function of surface roughness characteristics of the terrain and the stability of the atmosphere (Monin-Obukhov length, L). The concentrations estimated from the model compare favorably with the field observations of other investigators.