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Leveraging scientific community knowledge for air quality model chemistry parameterizations
Citation:
Pye, H., R. Schwantes, K. Barsanti, V. McNeill, AND G. Wolfe. Leveraging scientific community knowledge for air quality model chemistry parameterizations. EM Magazine. Air and Waste Management Association, Pittsburgh, PA, , 24-31, (2024).
Impact/Purpose:
Essentially all ozone and significant portions of fine particles (PM2.5) and hazardous air pollutants (HAPs) are produced in the atmosphere through chemical and physical processes. In air quality models such as CMAQ, the formation of these secondary species is described by a chemical mechanism. This article, co-authored by EPA, NOAA, NCAR, and NASA scientists as well as a professor from Columbia University, lays out what is needed to develop state-of-science chemical mechanisms and the value of leveraging a broad scientific community. CRACMM takes this community-based approach and is the focus of current ORD mechanism development efforts in CMAQ. Future versions of CRACMM will need to robustly predict criteria and hazardous air pollutants for application in emission control studies and for estimation of cancer and non-cancer risk of HAPs. CRACMM meets several needs: CRACMM addresses recommendations from the 2023 National Academies of Sciences, Engineering, and Medicine report on Transforming EPA Science to Meet Today's and Tomorrow's Challenges which encourages us to:“Improve the predictive capability of CMAQ” through “process-level knowledge” and have “continued collaboration with other organizations to develop measurement and modeling strategies for national air quality” (Recommendation 5-3). EPA ORD-NOAA CSL collaborations on CRACMM fall under a Memorandum of Agreement (MOA) on Cooperation in Forecasting Air Quality (2021, https://www.weather.gov/media/sti/NOAA-EPA%20MOA%20signed_2021.pdf) which indicates:“NOAA and EPA agree to collaborate on scientific research… including, but not limited to: developing air quality models and tools for integrating meteorology and air chemistry, including ozone and precursor species, aerosols and their properties.” The MOA identifies “Air quality models for predicting ambient concentrations” as an EPA deliverable. CRACMM implementation in NOAA model(s) will be performed in collaboration with NCAR and is covered under a NCAR-NOAA MOA for Co-development of a Common Modeling Infrastructure (2018, https://www.weather.gov/media/sti/nggps/18-064553_SignedMOU.pdf). In addition, CRACMM addresses requests from the 2018 EPA STAR Chemical Mechanisms RFA that identified a need for a “condensed mechanism” with an “integrated treatment of gas, aerosol, aqueous, and heterogeneous chemistry”that is “easily updated.” Co-author Prof. Faye McNeill is a STAR grantee recipient whose work has been incorporated in CRACMM.
Description:
Air pollution remains an important contributor to adverse health outcomes in the U.S. Currently, 121 million people, or one third of the U.S. population, live where National Ambient Air Quality Standards are violated.<span style='mso-element:field-begin'> ADDIN EN.CITE <EndNote><Cite><Author>U.S. Environmental Protection Agency</Author><Year>2023</Year><RecNum>656</RecNum><DisplayText><style face="superscript">1</style></DisplayText><record><rec-number>656</rec-number><foreign-keys><key app="EN" db-id="fes5adwp09t9v1eta5wpa2aiv5090pstsxws" timestamp="1695839048">656</key></foreign-keys><ref-type name="Report">27</ref-type><contributors><authors><author>U.S. Environmental Protection Agency,</author></authors></contributors><titles><title>Summary Nonattainment Area Population Exposure Report</title></titles><volume>2023</volume><number>10 October 2023</number><dates><year>2023</year><pub-dates><date>31 August 2023</date></pub-dates></dates><urls><related-urls><url>https://www3.epa.gov/airquality/greenbook/popexp.html</url></related-urls></urls></record></Cite></EndNote><span style='mso-element:field-separator'><span lang=EN style='font-family:"Times New Roman",serif'> In most cases, the criteria pollutants exceeding standards are ozone (O3) and fine particles (PM2.5). In addition to criteria pollutants, 188 substances known or suspected to cause cancer or other serious health effects are designated as hazardous air pollutants (HAPs). Essentially all O3 and significant portions of PM2.5 and HAPs are produced in the atmosphere through chemical and physical processes. In the case of PM2.5, subcomponents formed primarily from gases—sulfate, nitrate, ammonium, and secondary organic aerosol (SOA) —account for 60% of the U.S. county-level annual mean concentration.<span lang=EN style='font-family:"Times New Roman",serif'> ADDIN EN.CITE <EndNote><Cite><Author>Pye</Author><Year>2021</Year><RecNum>297</RecNum><DisplayText><style face="superscript">2</style></DisplayText><record><rec-number>297</rec-number><foreign-keys><key app="EN" db-id="fes5adwp09t9v1eta5wpa2aiv5090pstsxws" timestamp="1639689630">297</key></foreign-keys><ref-type name="Journal Article">17</ref-type><contributors><authors><author>Pye, Havala O. T.</author><author>Ward-Caviness, Cavin K.</author><author>Murphy, Ben N.</author><author>Appel, K. Wyat</author><author>Seltzer, Karl M.</author></authors></contributors><titles><title>Secondary organic aerosol association with cardiorespiratory disease mortality in the United States</title><secondary-title>Nature Communications</secondary-title></titles><periodical><full-title>Nature Communications</full-title><abbr-1>Nat. Commun.</abbr-1></periodical><pages>7215</pages><volume>12</volume><number>1</number><dates><year>2021</year><pub-dates><date>2021/12/16</date></pub-dates></dates><isbn>2041-1723</isbn><urls><related-urls><url>https://doi.org/10.1038/s41467-021-27484-1</url></related-urls></urls><electronic-resource-num>https://doi.org/10.1038/s41467-021-27484-1</electronic-resource-num></record></Cite></EndNote><span style='mso-element:field-separator'><span lang=EN style='font-family:"Times New Roman",serif'> In addition, 47% of the cancer risk and 25% of the noncancer risk from HAPs has been attributed to atmospheric chemistry rather than direct emissions.<span lang=EN style='font-family:"Times New Roman",serif'><span style='mso-element: field-begin'> ADDIN EN.CITE <EndNote><Cite><Author>Scheffe</Author><Year>2016</Year><RecNum>245</RecNum><DisplayText><style face="superscript">3</style></DisplayText><record><rec-number>245</rec-number><foreign-keys><key app="EN" db-id="fes5adwp09t9v1eta5wpa2aiv5090pstsxws" timestamp="1628625282">245</key></foreign-keys><ref-type name="Journal Article">17</ref-type><contributors><authors><author>Scheffe, Richard D.</author><author>Strum, Madeleine</author><author>Phillips, Sharon B.</author><author>Thurman, James</author><author>Eyth, Alison</author><author>Fudge, Steve</author><author>Morris, Mark</author><author>Palma, Ted</author><author>Cook, Richard</author></authors></contributors><titles><title>Hybrid modeling approach to estimate exposures of Hazardous Air Pollutants (HAPs) for the National Air Toxics Assessment (NATA)</title><secondary-title>Environmental Science & Technology</secondary-title></titles><periodical><full-title>Environmental Science & Technology</full-title><abbr-1>Environ. Sci. Technol.</abbr-1></periodical><pages>12356-12364</pages><volume>50</volume><number>22</number><dates><year>2016</year><pub-dates><date>2016/11/15</date></pub-dates></dates><publisher>American Chemical Society</publisher><isbn>0013-936X</isbn><urls><related-urls><url>https://doi.org/10.1021/acs.est.6b04752</url></related-urls></urls><electronic-resource-num>https://doi.org/10.1021/acs.est.6b04752</electronic-resource-num></record></Cite></EndNote><span style='mso-element:field-separator'><span lang=EN style='font-family:"Times New Roman",serif'> In this article, we introduce the role of chemical mechanisms in air quality models, a new community effort, and needs for further mechanism development.
