Analysis of a Finite Release of a Pollutant Followed by an Abrupt Change of Wind Direction

Abstract

The releases of pollutants to the atmosphere may be divided into three groups according to the length of the release: (i) Instantaneous release of a puff, (ii) Continuous (or quasicontinuous) release which creates an (quasi) infinite plume, (iii) The large group of intermediate cases of finite releases, which produce finite plumes. Many different methods exist, enabling the calculation of the concentration of the pollutant and the hazards resulting from its release. The methods range from simple gaussian models to very elaborated three dimensional numerical models. The major effort until the present time, concentrated in finding solutions to the first two groups of cases. The case of a steady wind direction and speed is fairly easy to handle, even with simple hand calculations, for the case of a puff as well as a (finite or infinite) plume, e.g. Slade (1968), Turner (1970).