Emission inventories are the key input files to SMOKE and emissions modeling. The data types that these inventories contain are called inventory pollutants (e.g., carbon monoxide, ammonia, mercury). By itself, SMOKE does not require specific data types in the inventory files it reads. However, the AQMs that SMOKE supports do require certain input data, called model species, which in turn requires SMOKE to use certain inventory pollutants.
In this section, we focus on the inventory files that SMOKE uses. Section 2.3.1, “Inventory data types” describes the major inventory types useable by SMOKE. In Section 2.3.2, “Inventory source categories”, we describe the inventory source categories, and in Section 2.3.3, “Inventory file formats” we discuss the inventory file formats. The remaining sections describe the various codes used in specific inventory sources: Section 2.3.4, “Country, state, and county codes”, Section 2.3.5, “Source Classification Codes”, Section 2.3.6, “Standard Industrial Classification codes”, Section 2.3.8, “Maximum Achievable Control Technology codes”, Section 2.3.9, “Source types: major and section-112 area sources” and Section 2.3.10, “Source types: nonroad and onroad mobile sources”.
SMOKE processes criteria, particulate, toxics, and activity data inventories. Activity data will be discussed along with on-road mobile sources in the next section. By criteria inventories, we mean inventories containing EPA’s criteria pollutants: carbon monoxide (CO), nitrogen oxides (NOx), and volatile organic compounds (VOC) or total organic gases (TOG). Particulate inventories contain ammonia (NH3), sulfur dioxide (SO2), particulate matter (PM) of size 10 microns or less (PM10), and PM of size 2.5 microns or less (PM2.5).
Additionally, SMOKE can process inventories with pre-speciated criteria and/or particulate emissions. For example, elemental carbon of size 2.5 microns or less can be provided as input to SMOKE directly, instead of letting SMOKE’s speciation step compute it from the PM2.5 total emissions. To ensure that SMOKE correctly processes the data when you are using pre-speciated emissions, other input files must be configured in specific ways, as explained in Section 4.4.10, “Use a different speciation mechanism or change speciation inputs”.
The toxics inventories that SMOKE can process are data from the National Emission Inventory (NEI) for Hazardous Air Pollutants (HAPs). This inventory contains hundreds of specific compounds representing the 188 HAPs defined by the Clear Air Act. The original list of 189 HAPs and modifications representing the current list are available from the EPA’s web site. The reason the inventory contains many more pollutants than 188 is because several on the list of 188 are pollutant groups, such as polycyclic organic matter, cyanide compounds and numerous metal compounds including chromium compounds, cadmium compounds, manganese compounds, and others. Note that because of these groups, specific compounds in the inventory in one inventory year may not exactly match the compounds in another inventory year. For example, one may have lead oxide reported one year but not in a subsequent year. However, those compounds not belonging to compound groups are likely to be in the inventory year after year, particularly the common gaseous HAPs emitted by mobile sources such as benzene, 1,3-butadiene, acrolein, formaldehyde, and acetaldehyde.