Abstract |
The Plume-in-Grid (PinG) module, and integral component of the Community Multiscale Air Quality (CMAQ) modeling system, has been extended to include the simulation of aerosol species and particulates concurrently with gas-phase photochemical species. The aerosol module already employed in the CMAQ/Chemical Transport Model (CCTM) was adapted and incorporated into the PinG algorithm, which also provides compatibility between the plume and CCTM Eulerian grid models during simulation. Test simulations were performed on a group of major point sources with tall stacks exhibiting a range of NOx and SOx emission rates situated in the Nashville, TN region. Due to the linkage between gaseous species and aerosols, various test simulations were performed with different combinations of chemical mechanisms and chemical solvers to investigate the impact on aerosol formation. Results using the Carbon Bond IV (CB-IV) chemical mechanism and the Gear chemical solver in the simulation with aerosol modeling are described. Differences in fine sulfate aerosol concentrations were found among the point sources with lower sulfate aerosol concentrations generated in the plumes of the highest NOx point sources. |