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Contribution of isoprene-derived organosulfates to free tropospheric aerosol mass

Froyd, K. D. and Murphy, S. M. and Murphy, D. M. and de Gouw, J. A. and Eddingsaas, N. C. and Wennberg, P. O. (2010) Contribution of isoprene-derived organosulfates to free tropospheric aerosol mass. Proceedings of the National Academy of Sciences of the United States of America, 107 (50). pp. 21360-21365. ISSN 0027-8424. PMCID PMC3003038.

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Recent laboratory studies have demonstrated that isoprene oxidation products can partition to atmospheric aerosols by reacting with condensed phase sulfuric acid, forming low-volatility organosulfate compounds. We have identified organosulfate compounds in free tropospheric aerosols by single particle mass spectrometry during several airborne field campaigns. One of these organosulfates is identified as the sulfate ester of IEPOX, a second generation oxidation product of isoprene. The patterns of IEPOX sulfate ester in ambient data generally followed the aerosol acidity and NOx dependence established by laboratory studies. Detection of the IEPOX sulfate ester was most sensitive using reduced ionization laser power, when it was observed in up to 80% of particles in the tropical free troposphere. Based on laboratory mass calibrations, IEPOX added > 0.4% to tropospheric aerosol mass in the remote tropics and up to 20% in regions downwind of isoprene sources. In the southeastern United States, when acidic aerosol was exposed to fresh isoprene emissions, accumulation of IEPOX increased aerosol mass by up to 3%. The IEPOX sulfate ester is therefore one of the most abundant single organic compounds measured in atmospheric aerosol. Our data show that acidity-dependent IEPOX uptake is a mechanism by which anthropogenic SO2 and marine dimethyl sulfide emissions generate secondary biogenic aerosol mass throughout the troposphere.

Item Type:Article
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URLURL TypeDescription DOIArticle CentralArticle
Murphy, S. M.0000-0002-6415-2607
de Gouw, J. A.0000-0002-0385-1826
Eddingsaas, N. C.0000-0003-1539-5415
Wennberg, P. O.0000-0002-6126-3854
Additional Information:© 2010 National Academy of Sciences. Edited by Mark H. Thiemens, University of California, San Diego, La Jolla, CA, and approved October 21, 2010 (received for review August 24, 2010). Published online before print November 22, 2010. We are grateful to Jerome Brioude for FLEXPART analysis of isoprene emissions, to Ann Middlebrook for AMS data from the ITCT/NEAQS 2004 campaign and PALMS data from the 1999 Atlanta Supersite, and to Jason Surratt for valuable input. This work was supported by NOAA base funding, NOAA climate change programs, NASA Earth Science Program Office for aircraft deployments, and the Camille and Henry Dreyfus Postdoctoral Program in Environmental Chemistry. S.M. Murphy acknowledges a National Research Council Research Associateship. Author contributions: K.D.F., D.M.M., and P.O.W. designed research; K.D.F., S.M.M., and J.A.d.G. performed research; K.D.F., S.M.M., and J.A.d.G. analyzed data; N.C.E. contributed new reagents/analytic tools; and K.D.F. wrote the paper.
Funding AgencyGrant Number
National Oceanic and Atmospheric Administration (NOAA)UNSPECIFIED
Camille and Henry Dreyfus FoundationUNSPECIFIED
National Research CouncilUNSPECIFIED
Subject Keywords:acid-catalyzed particle phase reactions epoxides free troposphere secondary organic aerosol
Issue or Number:50
PubMed Central ID:PMC3003038
Record Number:CaltechAUTHORS:20110222-133547224
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Official Citation:K. D. Froyd, S. M. Murphy, D. M. Murphy, J. A. de Gouw, N. C. Eddingsaas, and P. O. Wennberg Contribution of isoprene-derived organosulfates to free tropospheric aerosol mass PNAS 2010 107 (50) 21360-21365; published ahead of print November 22, 2010, doi:10.1073/pnas.1012561107
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:22427
Deposited By: Ruth Sustaita
Deposited On:22 Feb 2011 22:19
Last Modified:09 Mar 2020 13:19

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