MIT Libraries homeMIT Libraries logoDSpace@MIT

MIT
View Item 
  • DSpace@MIT Home
  • MIT Open Access Articles
  • MIT Open Access Articles
  • View Item
  • DSpace@MIT Home
  • MIT Open Access Articles
  • MIT Open Access Articles
  • View Item
JavaScript is disabled for your browser. Some features of this site may not work without it.

Effect of oxidant concentration, exposure time, and seed particles on secondary organic aerosol chemical composition and yield

Author(s)
Lambe, A. T.; Chhabra, P. S.; Onasch, T. B.; Brune, W. H.; Cummings, M. J.; Brogan, J. F.; Parmar, Y.; Worsnop, D. R.; Kolb, C. E.; Davidovits, P.; Hunter, James Freeman; Kroll, Jesse; ... Show more Show less
Thumbnail
DownloadKroll_Effect of oxidant.pdf (518.3Kb)
PUBLISHER_CC

Publisher with Creative Commons License

Creative Commons Attribution

Terms of use
Creative Commons Attribution 3.0 Unported license http://creativecommons.org/licenses/by/3.0/
Metadata
Show full item record
Abstract
We performed a systematic intercomparison study of the chemistry and yields of secondary organic aerosol (SOA) generated from OH oxidation of a common set of gasphase precursors in a Potential Aerosol Mass (PAM) continuous flow reactor and several environmental chambers. In the flow reactor, SOA precursors were oxidized using OH concentrations ranging from 2.0 × 10[superscript 8] to 2.2 × 10[superscript 10] molec cm[superscript −3] over exposure times of 100 s. In the environmental chambers, precursors were oxidized using OH concentrations ranging from 2 × 10[superscript 6] to 2 × 10[superscript 7] molec cm[superscript −3] over exposure times of several hours. The OH concentration in the chamber experiments is close to that found in the atmosphere, but the integrated OH exposure in the flow reactor can simulate atmospheric exposure times of multiple days compared to chamber exposure times of only a day or so. In most cases, for a specific SOA type the most-oxidized chamber SOA and the least-oxidized flow reactor SOA have similar mass spectra, oxygen-to-carbon and hydrogen-to-carbon ratios, and carbon oxidation states at integrated OH exposures between approximately 1 × 10[superscript 11] and 2 × 10[superscript 11] molec cm[superscript −3] s, or about 1–2 days of equivalent atmospheric oxidation. This observation suggests that in the range of available OH exposure overlap for the flow reactor and chambers, SOA elemental composition as measured by an aerosol mass spectrometer is similar whether the precursor is exposed to low OH concentrations over long exposure times or high OH concentrations over short exposure times. This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed particles are routinely used.
Date issued
2015-03
URI
http://hdl.handle.net/1721.1/110441
Department
Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
Journal
Atmospheric Chemistry and Physics Discussions
Publisher
Copernicus GmbH
Citation
Lambe, A. T. et al. “Comparison of Secondary Organic Aerosol Formed with an Aerosol Flow Reactor and Environmental Reaction Chambers: Effect of Oxidant Concentration, Exposure Time and Seed Particles on Chemical Composition and Yield.” Atmospheric Chemistry and Physics Discussions 14.22 (2014): 30575–30609.
Version: Final published version
ISSN
1680-7375
1680-7367

Collections
  • MIT Open Access Articles

Browse

All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

My Account

Login

Statistics

OA StatisticsStatistics by CountryStatistics by Department
MIT Libraries homeMIT Libraries logo

Find us on

Twitter Facebook Instagram YouTube RSS

MIT Libraries navigation

SearchHours & locationsBorrow & requestResearch supportAbout us
PrivacyPermissionsAccessibility
MIT
Massachusetts Institute of Technology
Content created by the MIT Libraries, CC BY-NC unless otherwise noted. Notify us about copyright concerns.