THE 2006 CMAQ RELEASE AND PLANS FOR 2007

The 2006 release of the Community Multiscale Air Quality (CMAQ) model (Version 4.6) includes upgrades to several model components as well as new modules for gas-phase chemistry and boundary layer mixing. Capabilities for simulation of hazardous air pollutants have been expanded to include more gas-phase toxics and several toxic metals. The mercury model has been updated and adapted to the new version of CMAQ. The CMAQ analysis tools, sulfur tracking and carbon source apportionment, have also been updated to operate with new physics, chemistry, and aerosol components. An overview of the new upgrades for CMAQ version 4.6 is provided in Section 2. Then, in Section 3, we take a preliminary look at the model evaluation for the CMAQv4.6 release. Section 4 outlines plans for further model development over the next year and beyond. Finally, a summary is presented in Section 5.