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Emissions Modeling Clearinghouse

Another step in modeling inventory development is speciation. This is the process of disaggregating inventory pollutants into individual chemical species components or groups of species. The need for speciation is determined by the inventory purpose. Inventory applications that require detailed speciation include photochemical modeling, air toxics inventories, chemical mass balance modeling, and visibility modeling.

Depending on the purpose of a particular emissions inventory, the inventory may include TOG, NOx, sulfur oxides (SOx), CO, total suspended particulate matter (TSP), particulate matter less than 10 micrometers in aerodynamic diameter (PM10), or ammonia (NH3). However, modeling inventories may require these emissions to be expressed in terms of other pollutants. Additionally, for some models, NOx emissions may need to be specified as NO and NO2. Also, PM may need to be separated into various fractions, such as PM10 and PM less than 2.5 micrometers in aerodynamic diameter (PM2.5).

Speciation of Mercury
Memorandum on the Clean Air Mercury Rule Hg speciation factors
Spreadsheet on the Clean Air Mercury Rule speciation factors
(PDF 230K)
(XLS 226K)
Speciation Profiles and Cross-reference files
Latest avaliable PM, VOC, and other speciation profiles and cross-reference files from EPA in SMOKE-ready format. See readme speciation.pdf for more inforation on which files to download.
(18 pdf)

EPA v4 platform (2005) ancillary data with speciation profiles and cross-reference files, supporting CB05 for CMAQ v4.7 CAP-BAFM ancillary_files.
See also http://www.epa.gov/ttn/chief/emch/index.html#2005

(XLS 1M)
EPA v3 platform (2002) ancillary data with speciation profiles and cross-reference files, supporting CB05 for CMAQ v4.5.
   CAP-only ancillary files
   CAP-HAP ancillary files
See also http://www.epa.gov/ttn/chief/emch/index.html#2002
(XLX 270)
Historical Documentation and Data
Speciation Profile Usage Memorandum (1/23/2009) This document describes the usage of the profile assignment, TOG conversion, and CBIV profile files.
(PDF 19K)
Source Category Code / Speciation Profile X-Reference File (3/8/2002) This file identifies both the PM and organic gases profile codes that EPA uses for each SCC. These data have been superceded by data provided in the previous data.
(XLS 1M)
VOC/ROG to TOG Conversion Ratios File (4/23/2003) This file provides the augmentation ratios, by SCC, to create the "TOG" emissions needed by the organic profiles. These data have been superceded by data provided in the previous data.
(XLS 270K)
Carbon Bond IV & PM Profiles File (3/8/2002)This file provides the molar split factors and mass fractions used to create CBIV lumped species and PM species from TOG and PM2.5 inventories.
(XLS 201K)
Titles and Documentation for PM Profiles (4/26/2005)
(XLS 30K)
Recommendations for the Update of PM2.5 Split Factors (9/29/2003)
(PDF 240K)
Historical Documentation and Data
Online data browser and Access database for viewing individual organic compound profiles (not lumped modeling species) for PM2.5 and total organic gases (TOG), including raw data for VOC-to-TOG factors.
Carbon Bond IV Exit EPA Disclaimer The Carbon Bond-IV Mechanism was developed mainly for urban smog and regional atmospheric modeling.
Carbon Bond 05 Exit EPA DisclaimerThe updated Carbon Bond (CB05) mechanism has been developed for use with the CMAQv4.6
SAPRC99 and SAPRCO7 Exit EPA Disclaimer Chemical Mechanism developed by Bill Carter at the University of California, Riverside.

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