Regional Modeling using One-Atmospheric Models to Address Regional Haze, 8-Hour Ozone and PM2.5 Air Quality

摘要

Five Regional Planning Organizations (RPOs) are performing regional ozone and particulate matter (PM) modeling to support the development of Regional Haze State Implementation Plans (SIPs) due in December 2007. The RPO modeling will also likely serve as the regional component for 8-hour ozone and fine particulate (PM2.5) SIPs due in June 2007 and April 2008, respectively. Two regional "one-atmosphere" photochemical grid models are being used by the RPOs for this purpose, the Models-3 Community Multi-scale Air Quality (CMAQ) modeling system and the Comprehensive Air quality Model with extensions (CAMx). This paper discussed the application of the CMAQ and CAMx models to support the Regional Haze, 8-hour ozone and PM2.5 SIPs. The model performance of the two models for ozone, and PM is discussed along with the use of advanced features in the two models that include: (1)Source Apportionment techniques including the Ozone Source Apportionment Technology (OSAT), PM Source Apportionment Technology (PSAT) and Tagged Species Source Apportionment (TSSA) approaches that provides source apportionment of the geographic regions and source categories, as well as initial and boundary conditions (ICBC) to ozone and PM species concentrations; (2)Decoupled Direct Method (DDM) sensitivity analysis that provides ozone and PM species sensitivity to emissions by source regions and category and ICBCs;and(3)Process Analysis(PA) that extracts chemical and mass flux processes from the model to help explain why the model estimates occurred. The current model performance capabilities of the CMAQ and CAMx models are provided along with the needs for improvements in emissions, meteorology, air quality inputs as well as model formulation.