For the atmospheric dispersion of pollutants in low wind conditions, a steady-state mathemat-
ical model has been formulated which takes into account the diffusion in all the coordinate directions and the advection due to mean wind. The analytical solution has been obtained by assuming constant eddy diffusivity coefficients in the advection-diffusion equation. The solution reduces to a familiar form which
yields the standard Gaussian plume solution when slender or thin plume approximation is invoked. The analytical solution obtained matches with the Gaussian plume solution for ground-level concentration at the plume centreline.
The model has been evaluated with data collected from the experiments conducted at the sports ground of the Indian Institute of Technology, Delhi (India). The results are reasonably good keeping in view the limitations of the data and the model. The model performs well as indicated by the agreement between the observed oncentrations and those calculated using 30 min and 3 min averaging.