An application of Lagrangian stochastic modelling to dispersion during shoreline fumigation

Abstract

A Lagrangian stochastic model, developed by the authors in a previous study, is applied to describe the dispersion of contaminants during shoreline fumigation. Mixed layer scaling is applied and the model dimensionless near-surface cross-wind integrated concentrations ( C y ) together with the concentration contour plots, are calculated for slow and fast entrainment rates. The water tank measurements of Deardorff and Willis (1982, Atmospheric Environment 16, 1159–1170), which are the dimensionaless near-surface plume centreline concentrations, are converted into the near-surface C y values following an appropriate assumption concerning the lateral growth of the plume. The model near-surface C y values compare satisfactorily with the water tank measurements. The model and the water tank measurements are representative of shoreline fumigation if the streamwise diffusion and shear are assumed to be negligible in the thermal internal boundary layer. The results are equally applicable (provided the wind is calm) to the nocturnal inversion break up fumigation which occurs early in the morning.