RLINE: A line source dispersion model for near-surface releases

This paper describes the formulation and evaluation of RLINE, a Research LINE source model for near-surface releases. The model is designed to simulate mobile source pollutant dispersion to support the assessment of human exposures in near-roadway environments where a significant portion of the population spends time. The model uses an efficient numerical integration scheme to integrate the contributions of point sources used to represent a line-source. Emphasis has been placed on estimates of concentrations very near to the source line. The near-surface dispersion algorithms are based on new formulations of horizontal and vertical dispersion within the atmospheric surface layer, details of which are described in a companion paper (Venkatram et al., 2013). This paper describes the general formulations of the RLINE model, the meteorological inputs for the model, the numerical integration techniques, the handling of receptors close to the line source, and the performance of the model against developmental data bases and near-road concentrations from independent field studies conducted along actual highway segments.