Written for graduate students and practicing professionals, this book explains contemporary numerical modeling of air pollution in the lowest layer of the atmosphere. It provides some historical background into the scientific formulation of fluid mechanics and the subsequent development of the atmospheric continuity equation. This is followed by an extensive narrative of how computer-based numerical simulations have enabled the discipline to gain increasing traction in concert with the advancement of computational power. Numerical modeling of air pollutant emissions, relevant meteorological fields, and air pollutant concentrations themselves are given a thorough treatment.
Generalities about models, numerical models, physical models, and the rationale for employing them. Basics of the atmospheric “continuity equations”, their insolvability because of lack of analytic solutions, and therefore the necessity to employ numerical models. History of computer-based numerical modeling and prospects for future computational gains. Air pollutant emissions and emission modeling. SMOKE, the present-day model for building gridded, hourly emissions. Box models. Gaussian diffusion modeling, with emphasis on the presently EPA-approved model called AERMOD. Meteorological modeling: MM5 and WRF. Lagrangian modeling concepts and examples (e.g. Calpuff, Hysplit, etc.). Eulerian modeling concepts and examples (WRF-chem, Chem-X, CMAQ. Deposition models. Human exposure models. Toxicological models. Summary.