Recent concerns about effects of automobile emissions on the health of people living close to roads have motivated an examination of models to estimate dispersion in the surface boundary layer. This examination led to new formulations for horizontal and vertical plume spread described in Venkatram et al. (2013). Concentration estimates based on the proposed plume spread equations compare well with data from both the Prairie Grass experiment (Barad, 1958) as well as the recently conducted Idaho Falls experiment (Finn et al., 2010). This paper describes a simpler approach to deriving the new equations proposed in the earlier paper.
Keywords: plume spread, near-road concentrations, surface releases, similarity theory, model performance, Prairie Grass experiment, Idaho Falls experiment