Comparative study of Gaussian dispersion formulae within the Polyphemus platform: evaluation with Prairie Grass and Kincaid experiments
نویسندگان
چکیده
This paper details a number of existing formulations used in Gaussian models in a clear and usable way, and provides a comparison within a single framework—the Gaussian plume and puff models of the air quality modeling system Polyphemus. The emphasis is made on the comparison between (1) the parameterizations to compute the standard deviations and (2) the plume rise schemes. The Gaussian formulae are first described and theoretically compared. Their evaluation is then ensured by comparison to the observations as well as to several well-known Gaussian and CFD models performance. The model results compare well with the other Gaussian models for two of the three parameterizations for standard deviations, Briggs’s and similarity-theory, while Doury’s shows a tendency to underestimate the concentrations because of a large horizontal spread. The results with Kincaid experiment point out the sensitivity to the plume rise scheme and the importance of an accurate modeling of the plume interactions with the inversion layer. Using three parameterizations for the standard deviations and the same number of plume rise schemes, we were able to highlight a large variability in the model outputs.
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