Source Code Assignment to Speciation Profiles
The emission inventory source categories are represented by an 8-digit Source Classification Code (SCC) for point sources, or a 14-digit Emission Inventory Code (EIC) for area and mobile sources. For the INTERACTIVE OPTION, there are separate files that can be accessed for PM and for TOG, that provide the linkages between the speciation profiles and the codes.
In the SCCASSNFRACTION files are speciation profile version-specific, and the PM & organic profiles are assigned to each source category by SCC and EIC. This version ( Version ID= 10001 ) of the SCCASSNFRACTION file has been partitioned into the following 3 sections. For the download files, these files also contain the fraction of reactive organic gas (FROG) values for organic profiles, and the PM 10 and PM 2.5 size fraction data for PM profiles. Remember to be careful if you mix the interactive option and download option data. In all cases, the interactive option data are reported as weight fractions, but, in some cases, the download option data are reported as weight percent. The field names may also be different, and the file structures are also different.
For either option, some of the Organic Gas Speciation Profile assignments related to motor vehicles and fuel evaporative sources vary by the inventory year of interest, due to changes in fuel composition and vehicle fleet composition over time. For the interactive option, there are separate source category assignment files for each year. For the download option, all of the years are included in the same file.