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Nonlinear Response of Ozone to Emissions: Source Apportionment and Sensitivity Analysis

Cohan, Daniel S. and Hakami, Amir and Hu, Yongtao and Russell, Armistead G. (2005) Nonlinear Response of Ozone to Emissions: Source Apportionment and Sensitivity Analysis. Environmental Science and Technology, 39 (17). pp. 6739-6748. ISSN 0013-936X. doi:10.1021/es048664m.

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For secondary air pollutants, precursor emissions may impact concentrations in nonlinear and interdependent manners. We explore the nonlinear responses of one such pollutant, ozone, to emissions of its precursors, nitrogen oxides (NOx) and volatile organic compounds. Modeling is conducted for a high ozone episode in the southeastern United States, applying a second-order direct sensitivity method in a regional air quality model. As applied here, the sensitivity method neglects most aerosol and aqueous chemistry processes. Inclusion of second-order sensitivities is shown to enable accurate characterization of response to large perturbations in emissions. An index is introduced to characterize the nonlinearity of ozone response to NO_x emitted from each source region. Nonlinearity is found to increase with the tonnage and emission density of the source region. Interactions among the impacts of emission sources are shown to lead to discrepancies between source contribution attributed to an ensemble of emitters and the sum of the contributions attributed to each component. A method is introduced for applying these “cross-sensitivity” interactions to assess the uncertainty of sensitivity and source apportionment estimates arising from uncertainty in an emissions inventory. For ozone response to NO_x, underestimates in emission rates lead to underprediction of total source contribution but overprediction of per-ton sensitivity.

Item Type:Article
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Additional Information:© 2005 American Chemical Society. Publication Date (Web): August 2, 2005. This work was conducted as part of the Fall-Line Air Quality Study funded by the Georgia Environmental Protection Division. Additional financial support came from the U.S. Environmental Protection Agency (grants R-82897601 and RD-83096001) and from a National Science Foundation Graduate Research Fellowship to D.C. Alper Unal created the map of Georgia regions. The text benefited from the constructive comments of three anonymous reviewers.
Funding AgencyGrant Number
Georgia Environmental Protection DivisionUNSPECIFIED
Environmental Protection Agency (EPA)R-82897601
Environmental Protection Agency (EPA)RD-83096001
NSF Graduate Research FellowshipUNSPECIFIED
Issue or Number:17
Record Number:CaltechAUTHORS:20170314-155032373
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Official Citation:Nonlinear Response of Ozone to Emissions:  Source Apportionment and Sensitivity Analysis Daniel S. Cohan, Amir Hakami, Yongtao Hu, and, and Armistead G. Russell Environmental Science & Technology 2005 39 (17), 6739-6748 DOI: 10.1021/es048664m
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:75119
Deposited By: Tony Diaz
Deposited On:15 Mar 2017 14:03
Last Modified:15 Nov 2021 16:30

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