Using a Regional Chemical Transport Model for the Analysis of Gaseous and Particulate Air Pollutants in the Mexico City Metropolitan Area

Air quality in the Mexico City Metropolitan Area (MCMA) is the subject of many studies due to concerns from high emissions and their adverse effects on public health and the environment. In this study, a high resolution simulation is performed with the Community Multi-scale Air Quality modeling system (CMAQ) using meteorology generated by the Weather Research Forecasting system (WRF). The boundary conditions for CMAQ are provided by the Goddard Earth Observing System-CHEMistry model (GEOS-Chem). The simulation period was March 2-7, 2006. Hourly species concentrations of O3, NOx, CO, SO2, PM10, and PM2.5 for the period were provided by the Automatic Air Quality Monitoring Network (labeled as RAMA). Preliminary evaluation showed GEOS-Chem and CMAQ being in good agreement with their predicted concentrations. In comparison with the base case boundary conditions, the GEOS-Chem case performs better and predicts closer to the observed values of O3, NOx, PM10, PM2.5, and SO2. Particle trajectory analysis was performed using the HYbrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT) to ascertain the major sources of SO2 emitters and their impact on the MCMA