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An assessment of important SPECIATE profiles in the EPA emissions modeling platform and current data gaps
Citation:
Bray, C., M. Strum, H. Simon, L. Riddick, M. Kosusko, M. Menetrez, M. Hays, AND V. Rao. An assessment of important SPECIATE profiles in the EPA emissions modeling platform and current data gaps. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, 207:93-104, (2019). https://doi.org/10.1016/j.atmosenv.2019.03.013
Impact/Purpose:
SPECIATE is the EPA's repository of volatile organic gas and particulate matter (PM) speciation profiles of air pollution sources. It contains more than 5,700 specific profiles used by the air modeling community within and outside of EPA, including CMAQ, and is used in creating EPA’s National Emissions Inventory. This paper will help focus ORD and the greater scientific community’s measurement research to the most critical data profile needs; ranking profiles by mass, quality, and many other weighted measures. The paper describes the ranking process and identifies the most critical measurement needs based on rankings.
Description:
The United States (US) Environmental Protection Agency (EPA)'s SPECIATE database contains speciated particulate matter (PM) and volatile organic compound (VOC) emissions profiles. Emissions profiles from anthropogenic combustion, industry, wildfires, and agricultural sources among others are key inputs for creating chemically-resolved emissions inventories for air quality modeling. While the database and its use for air quality modeling are routinely updated and evaluated, this work sets out to systematically prioritize future improvements and communicate speciation data needs to the research community. We first identify the most prominent profiles (PM and VOC) used in the EPA's 2014 emissions modeling platform based on PM mass and VOC mass and reactivity. It is important to note that the on-road profiles were excluded from this analysis since speciation for these profiles is computed internally in the MOVES model. We then investigate these profiles further for quality and to determine whether they were being appropriately matched to source types while also considering regional variability of speciated pollutants. We then applied a quantitative needs assessment ranking system which rates the profile based on age, appropriateness (i.e. is the profile being used appropriately), prevalence in the EPA modeling platform and the quality of the reference. Our analysis shows that the highest ranked profiles (e.g. profile assignments with the highest priority for updates) include PM2.5 profiles for fires (prescribed, agricultural and wild) and VOC profiles for crude oil storage tanks and residential wood combustion of pine wood. Top ranked profiles may indicate either that there are problems with the currently available source testing or that current mappings of profiles to source categories within EPA's modeling platform need improvement. Through this process, we have identified 29 emissions source categories that would benefit from updated mapping. Many of these mapping mismatches are due to lack of emissions testing for appropriate source categories. In addition, we conclude that new source emissions testing would be especially beneficial for residential wood combustion, nonroad gasoline exhaust and nonroad diesel equipment.
URLs/Downloads:
DOI: An assessment of important SPECIATE profiles in the EPA emissions modeling platform and current data gaps