Formulation of a second-generation reactive flume and visibility model

The formulation of a second-generation reactive plume and visibility model, the Reactive and Optics Model of Emissions (ROME), is presented. This model presents the following improvements over existing plume visibility models. Chemical transformations in the gas phase, aqueous phase, and particles are simulated by means of a comprehensive chemical kinetic mechanism. Aerosol dynamics is simulated using a sectional representation of the aerosol size distribution. This approach allows an efficient treatment of radiative transfer calculations. Plume diffusion is treated according to several options, including a second-order closure algorithm for instantaneous plume concentrations. ROME is applied to a case study to illustrate the relative effects of NOx and primary particulate emissions on plume visual appearance.