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| Titel |
Total observed organic carbon (TOOC) in the atmosphere: a synthesis of North American observations |
| VerfasserIn |
C. L. Heald, A. H. Goldstein, J. D. Allan, A. C. Aiken, E. Apel, E. L. Atlas, A. K. Baker, T. S. Bates, A. J. Beyersdorf, D. R. Blake, T. Campos, H. Coe, J. D. Crounse, P. F. DeCarlo, J. A. Gouw, E. J. Dunlea, F. M. Flocke, A. Fried, P. Goldan, R. J. Griffin, S. C. Herndon, J. S. Holloway, R. Holzinger, J. L. Jimenez, W. Junkermann, W. C. Kuster, A. C. Lewis, S. Meinardi, D. B. Millet, T. Onasch, A. Polidori, P. K. Quinn, D. D. Riemer, J. M. Roberts, D. Salcedo, B. Sive, A. L. Swanson, R. Talbot, C. Warneke, R. J. Weber, P. Weibring, P. O. Wennberg, D. R. Worsnop, A. E. Wittig, R. Zhang, J. Zheng, W. Zheng |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 8, no. 7 ; Nr. 8, no. 7 (2008-04-08), S.2007-2025 |
| Datensatznummer |
250006032
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| Publikation (Nr.) |
 copernicus.org/acp-8-2007-2008.pdf |
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| Zusammenfassung |
| Measurements of organic carbon compounds in both the gas and particle phases
made upwind, over and downwind of North America are synthesized to
examine the total observed organic carbon (TOOC) in the atmosphere over this region. These
include measurements made aboard the NOAA WP-3 and BAe-146 aircraft, the
NOAA research vessel Ronald H. Brown, and at the Thompson Farm and Chebogue
Point surface sites during the summer 2004 ICARTT campaign. Both winter and
summer 2002 measurements during the Pittsburgh Air Quality Study are also
included. Lastly, the spring 2002 observations at Trinidad Head, CA, surface
measurements made in March 2006 in Mexico City and coincidentally aboard the
C-130 aircraft during the MILAGRO campaign and later during the IMPEX
campaign off the northwestern United States are incorporated. Concentrations
of TOOC in these datasets span more than two orders of magnitude. The
daytime mean TOOC ranges from 4.0 to 456 μgC m−3 from the cleanest
site (Trinidad Head) to the most polluted (Mexico City). Organic aerosol
makes up 3–17% of this mean TOOC, with highest fractions reported over
the northeastern United States, where organic aerosol can comprise up to
50% of TOOC. Carbon monoxide concentrations explain 46 to 86% of the
variability in TOOC, with highest TOOC/CO slopes in regions with fresh
anthropogenic influence, where we also expect the highest degree of mass
closure for TOOC. Correlation with isoprene, formaldehyde, methyl vinyl
ketone and methacrolein also indicates that biogenic activity contributes
substantially to the variability of TOOC, yet these tracers of biogenic
oxidation sources do not explain the variability in organic aerosol observed
over North America. We highlight the critical need to develop measurement
techniques to routinely detect total gas phase VOCs, and to deploy
comprehensive suites of TOOC instruments in diverse environments to quantify
the ambient evolution of organic carbon from source to sink. |
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