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dc.contributor.authorNguyen, Tran B.
dc.contributor.authorCrounse, John D.
dc.contributor.authorTeng, Alex P.
dc.contributor.authorSt. Clair, Jason M.
dc.contributor.authorPaulot, Fabien
dc.contributor.authorWolfe, Glenn M.
dc.contributor.authorWennberg, Paul O.
dc.date.accessioned2020-06-17T16:21:49Z
dc.date.available2020-06-17T16:21:49Z
dc.date.issued2015-02-03
dc.description.abstractWe report fluxes and dry deposition velocities for 16 atmospheric compounds above a southeastern United States forest, including: hydrogen peroxide (H₂O₂), nitric acid (HNO₃), hydrogen cyanide (HCN), hydroxymethyl hydroperoxide, peroxyacetic acid, organic hydroxy nitrates, and other multifunctional species derived from the oxidation of isoprene and monoterpenes. The data suggest that dry deposition is the dominant daytime sink for small, saturated oxygenates. Greater than 6 wt %C emitted as isoprene by the forest was returned by dry deposition of its oxidized products. Peroxides account for a large fraction of the oxidant flux, possibly eclipsing ozone in more pristine regions. The measured organic nitrates comprise a sizable portion (15%) of the oxidized nitrogen input into the canopy, with HNO₃ making up the balance. We observe that water-soluble compounds (e.g., strong acids and hydroperoxides) deposit with low surface resistance whereas compounds with moderate solubility (e.g., organic nitrates and hydroxycarbonyls) or poor solubility (e.g., HCN) exhibited reduced uptake at the surface of plants. To first order, the relative deposition velocities of water-soluble compounds are constrained by their molecular diffusivity. From resistance modeling, we infer a substantial emission flux of formic acid at the canopy level (∼1 nmol m⁻²⋅s⁻¹). GEOS−Chem, a widely used atmospheric chemical transport model, currently underestimates dry deposition for most molecules studied in this work. Reconciling GEOS−Chem deposition velocities with observations resulted in up to a 45% decrease in the simulated surface concentration of trace gases.en_US
dc.description.sponsorshipWe thank the organizers and committee members of the SOAS campaign: A. G. Carlton, A. H. Goldstein, J. L. Jimenez, R. W. Pinder, J. de Gouw, B. J. Turpin, and A. B. Guenther. We acknowledge C. J. Groff at Purdue University for his help with leaf area index measurements and tree surveys. We thank D. J. Jacob and the Atmospheric Chemistry Modeling Group at Harvard University for making GEOS−Chem available for this work. Meteorological data used in the GEOS−Chem simulations were provided by the Global Modeling and Assimilation Office at NASA Goddard Space Flight Center. We acknowledge funding from the National Science Foundation (NSF) under Grant AGS-1240604 and NSF Postdoctoral Research Fellowship program Award AGS-1331360. Financial and logistical support for SOAS was provided by the NSF, the Earth Observing Laboratory at the National Center for Atmospheric Research (operated by NSF), the personnel at Atmospheric Research and Analysis, and the Electric Power Research Institute.en_US
dc.description.urihttps://www.pnas.org/content/112/5/E392en_US
dc.format.extent10 pagesen_US
dc.genreconference papers and proceedingsen_US
dc.identifierdoi:10.13016/m25o2i-90y8
dc.identifier.citationTran B. Nguyen et al., Rapid deposition of oxidized biogenic compounds to a temperate forest, PNAS 112 (5) E392-E401(2015), https://doi.org/10.1073/pnas.1418702112en_US
dc.identifier.urihttps://doi.org/10.1073/pnas.1418702112
dc.identifier.urihttp://hdl.handle.net/11603/18911
dc.language.isoen_USen_US
dc.relation.isAvailableAtThe University of Maryland, Baltimore County (UMBC)
dc.relation.ispartofUMBC Joint Center for Earth Systems Technology
dc.relation.ispartofUMBC Faculty Collection
dc.relation.ispartofUMBC Physics Department
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.rights© 2015 National Academy of Sciences*
dc.titleRapid deposition of oxidized biogenic compounds to a temperate foresten_US
dc.typeTexten_US


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