Evaluation of grid-based ozone and PM Modeling for a 1999 summer episode
Q. Sun, A. Chandrasekar and P.G. Georgopoulos (EOHSI, UMDNJ - R. W. Johnson Medical School and Rutgers University)
This study presents an evaluation of the performance of a multiscale photochemical air quality modeling system in predicting ambient ozone and PM concentrations over the Northeastern U.S. The air quality model used in this study is Community Multiscale Air Quality (CMAQ) model, a component of US EPA's Models-3. The emissions data were processed from the National Emissions Trends (NET) inventory using MCNC's Sparse Matrix Operator Kernel Emissions (SMOKE) modeling system, and the meteorological inputs were developed using the Fifth Generation NCAR-Penn State Mesoscale Model (MM5). Fourteen layers in the vertical direction and three levels of nested domains are used in the MM5 simulations, with grid resolutions of 36km for the outmost domain, 12km for the intermediate domain and 4km for the innermost domain. The outmost domain encompasses the eastern United States (the OTAG, Ozone Transport Assessment Group, domain), and the innermost 4km domain focuses on the State of New Jersey and the metropolitan Philadelphia area. The meteorological and air quality simulations were carried out for two weeks starting July 11, 1999. The CMAQ simulations also employed three levels of nested grids with resolutions of 36, 12 and 4km. The results from the above simulations are compared with data from US EPA's Aerometric Information Retrieval System (AIRS), as well as with data from the North East Ozone and Particle Study (NE-OPS) field study that took place over the Philadelphia area during the period under consideration, to assess performances of MM5 and CMAQ in predicting meteorological and air quality patterns.