11 pages, five Figures and one Table.

CMAQ is configured with detailed implementation of horizontal and vertical advection based on the Piecewise Parabolic Method (PPM), turbulent diffusion based on K-theory, chemistry in the gas, liquid, and particulate phases using a modified version of the CBM-IV chemical mechanism (CB4-AQ-AE3) (Gery et al., 1994), dry deposition, and cloud physics and chemistry (CLOUD-RADM) (15). Hourly meteorological parameters, including temperature, wind velocities, humidity, surface pressure, and solar radiation, are obtained from the 5th Generation Mesoscale Model (MM5) (Grell et al., 1994). Anthropogenic emissions of nitrogen oxides (NOx), sulfur dioxide (SO2), carbon monoxide (CO), volatile organic compounds (VOCs), and ammonia (NH3) are obtained from the county level U.S. EPA 1996 National Emissions Trends inventory and processed with the Sparse Matrix Operator Kernel Emissions (SMOKE) model (Houyoux et al., 2000). Vehicle emissions of NOx, VOCs, CO and primary particulate matter (PM) are prepared using MOBILE5 (US EPA, 2003). Biogenic emissions, including NOx and VOCs, are obtained from the biogenic emissions inventory system, version 3 (BEIS3) (Pierce et al., 1998)