On the dispersion of particles in the atmosphere

The method of moments is used to predict the spatial and temporal dispersion of a cloud of particles released in the atmosphere. The moment equations involve an eddy diffusivity, and a turbulence parameterization is developed to obtain the tensor eddy diffusivity which takes into account the anisotropy of the flow. The parabolic equations for the moments of the distribution are solved by a finite element method. The differences between the data requirements for Lagrangian statistical models and those for eddy diffusivity models are discussed in relation to the comparison of model predictions with observations.