Dispersion in stable boundary layers using large-eddy simulation

Large-eddy simulation has been used to investigate dispersion under slight and moderate stability conditions. Numerically calculated flow trajectories have been used to follow the paths of a large number of particles released into the turbulent domain in order to study the dispersion properties. The vertical spread from the large-eddy simulations and from a model based on the ideas of Pearson et al. (1983, J. Fluid Mech. 120, 219–249) shows different qualitative behaviour although they agree quantitatively within a factor of 2. Possible reasons for the qualitative disagreement are discussed. In the horizontal plane, results show a bending of the plume which is produced by the turning of the wind with height in stable conditions.