Show simple item record

dc.contributor.authorWolfe, G. M.
dc.contributor.authorKaiser, J.
dc.contributor.authorHanisco, T. F.
dc.contributor.authorKeutsch, F. N.
dc.contributor.authorGouw, J. A. de
dc.contributor.authorGilman, J.B.
dc.contributor.authorGraus, M.
dc.contributor.authorHatch, C. D.
dc.contributor.authorHolloway, J.
dc.contributor.authorHorowitz, L. W.
dc.contributor.authorLee, B. H.
dc.contributor.authorLerner, B.M.
dc.contributor.authorLopez-Hilifiker, F.
dc.contributor.authorMao, J.
dc.contributor.authorMarvin, M. R.
dc.contributor.authorPeisch, J.
dc.contributor.authorPollack, I. B.
dc.contributor.authorRobert, J. M.
dc.contributor.authorRyerson, T. B.
dc.contributor.authorThornton, J. A.
dc.contributor.authorVeres, P. R.
dc.contributor.authorWarneke, C.
dc.date.accessioned2020-09-15T18:52:30Z
dc.date.available2020-09-15T18:52:30Z
dc.date.issued2016-03-02
dc.description.abstractThe chemical link between isoprene and formaldehyde (HCHO) is a strong, nonlinear function of NOx (i.e., NO + NO2). This relationship is a linchpin for top-down isoprene emission inventory verification from orbital HCHO column observations. It is also a benchmark for overall photochemical mechanism performance with regard to VOC oxidation. Using a comprehensive suite of airborne in situ observations over the southeast US, we quantify HCHO production across the urban–rural spectrum. Analysis of isoprene and its major first-generation oxidation products allows us to define both a "prompt" yield of HCHO (molecules of HCHO produced per molecule of freshly emitted isoprene) and the background HCHO mixing ratio (from oxidation of longer-lived hydrocarbons). Over the range of observed NOx values (roughly 0.1–2 ppbv), the prompt yield increases by a factor of 3 (from 0.3 to 0.9 ppbv ppbv−1), while background HCHO increases by a factor of 2 (from 1.6 to 3.3 ppbv). We apply the same method to evaluate the performance of both a global chemical transport model (AM3) and a measurement-constrained 0-D steady-state box model. Both models reproduce the NOx dependence of the prompt HCHO yield, illustrating that models with updated isoprene oxidation mechanisms can adequately capture the link between HCHO and recent isoprene emissions. On the other hand, both models underestimate background HCHO mixing ratios, suggesting missing HCHO precursors, inadequate representation of later-generation isoprene degradation and/or underestimated hydroxyl radical concentrations. Detailed process rates from the box model simulation demonstrate a 3-fold increase in HCHO production across the range of observed NOx values, driven by a 100 % increase in OH and a 40 % increase in branching of organic peroxy radical reactions to produce HCHO.en_US
dc.description.sponsorshipWe are grateful to NOAA AOC and the flight crew of the WP-3D for enabling a super awesome mission. HCHO measurement efforts were supported by US EPA Science to Achieve Results (STAR) program grant 83540601 and NASA grant NH10ZDA001N-SEAC4RS. Analysis was supported by NASA ACCDAM grant NNX14AP48G. J. Kaiser acknowledges support from NASA ESSF grant NNX14AK97H. C. D. Hatch was supported by the Hendrix faculty grant and the Hendrix College Odyssey program. J. Mao and L. W. Horowitz acknowledge support from NOAA Climate Program Office grant # NA13OAR4310071. This research has not been subjected to any EPA review and therefore does not necessarily reflect the views of the agency, and no official endorsement should be inferred.en_US
dc.description.urihttps://acp.copernicus.org/articles/16/2597/2016/en_US
dc.format.extent14 pagesen_US
dc.genrejournal articlesen_US
dc.identifierdoi:10.13016/m2bpx9-hwjy
dc.identifier.citationWolfe, G. M., Kaiser, J., Hanisco, T. F., Keutsch, F. N., de Gouw, J. A., Gilman, J. B., Graus, M., Hatch, C. D., Holloway, J., Horowitz, L. W., Lee, B. H., Lerner, B. M., Lopez-Hilifiker, F., Mao, J., Marvin, M. R., Peischl, J., Pollack, I. B., Roberts, J. M., Ryerson, T. B., Thornton, J. A., Veres, P. R., and Warneke, C.: Formaldehyde production from isoprene oxidation across NOx regimes, Atmos. Chem. Phys., 16, 2597–2610, https://doi.org/10.5194/acp-16-2597-2016, 2016.en_US
dc.identifier.urihttps://doi.org/10.5194/acp-16-2597-2016
dc.identifier.urihttp://hdl.handle.net/11603/19658
dc.language.isoen_USen_US
dc.publisherCopernicusen_US
dc.relation.isAvailableAtThe University of Maryland, Baltimore County (UMBC)
dc.relation.ispartofUMBC Joint Center for Earth Systems Technology
dc.relation.ispartofUMBC Physics Department
dc.relation.ispartofUMBC Faculty Collection
dc.rightsThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
dc.rightsPublic Domain Mark 1.0*
dc.rightsThis work was written as part of one of the author's official duties as an Employee of the United States Government and is therefore a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
dc.rights.urihttp://creativecommons.org/publicdomain/mark/1.0/*
dc.titleFormaldehyde production from isoprene oxidation across NOx regimesen_US
dc.typeTexten_US


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record

This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
Except where otherwise noted, this item's license is described as This item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.