A model for simulating atmospheric dispersion in low-wind conditions

A practical model for low-wind conditions was derived by integration of an instantaneous three-dimensional Gaussian puff equation, in which wind speed was assumed to be zero and standard deviations of a smoke (σy and σz) were expressed as a linear function of the dispersion time. When the plume spreads σy and σz were assumed to be linear functions of dispersion time, the proportionality coefficients for σy and σz) derived from the air tracer experiments were about 0.30-0.40 and 0.09-0.18 m/s, respectively.