Source apportionment for regional haze planning will utilize results from various modeling techniques:

• SOx NOx Tracer using CAMx PM Source Apportionment (PSAT): Regional gridded dispersion model simulations with SOx and NOx emissions source categories tagged and traced from emissions source location to Class I receptor site. Data Provided by the RMC
• Organic Aerosol Tracer using CMAQ: [Available in late 2006] Regional gridded dispersion modeling simulations tracing 3 groups of organic particulate matter: 1) anthropogenic secondary organic mass resulting from aromatic VOCs such as xylene, toluene, and cresols; 2) biogenic secondary organic mass, resulting from biogenic VOCs, such as terpenes; and 3) primary organic mass, resulting from direct organic mass emissions such as primary particulate organic emissions.
• WEP (Weighted Emissions Potential): Emissions inventories for all source categories and species for the 2000-04 Baseline and 2018 Base Case emissions scenarios used in modeling simulations are multiplied by the 2000-04 Air Mass Residence Time values at each Class I area, producing maps and charts of the Weighted Emissions Potential to contribute to haze.
• PMF Receptor Modeling: This receptor modeling technique, called Positive Matrix Factorization, analyzes the statistical relationships among monitored IMPROVE chemical species over time at Class I areas, and provides some additional assessment of the contribution to haze of source groups identified in the analysis. The method description, analysis performed, and the results at presented on the Causes of Haze Assessment website.