DIFFUSION IN A LAGRANGIAN MULTIPLE PARTICLE MODEL - A SENSITIVITY STUDY

The U.K. Meteorological Office Nuclear Accident-Dispersion Model (NAME) has been run in seven different configurations to produce hindcasts of the spread of the Kuwait smoke plume terminating at 00UTC 29 March 1991. This paper discusses the ways in which the model results differ when the model parameters, in particular those relating to horizontal and vertical turbulent diffusion, are changed. The results are compared with the plume observed by satellite photograph and with aircraft measurements made during a sortie by the MRF C130. In the course of the analysis the paper explores in some detail the morphology of a complex plume. The concluding discussions focus on the sensitivity of the dispersion, and the diagnostics of concentration and deposition, to the estimation of boundary layer depth in models of ''Monte Carlo'' type.