The APT Computer Program for the Numerical Solution of Problems in Atmospheric Dispersion

The analysis of the dispersion of pollutants issuing from sources near the ground into the atmospheric boundary layer has traditionally been accomplished via so-called Gaussian plume models. It is assumed that the flow field properties are invariant in the lateral and downwind directions which, along with other simplifying assumptions, allows the concentration field to be described by a Gaussian form; simplicity being one of the models’main attractions. Such models may be modified to take account of the duration of release and the frictional drag of the underlying surface (Clarke 1979). Dispersion may be treated by ‘K’ profile models (for example Maul (1977)) but it is difficult to specify the diffusivity profile from routine meteorological measurements.