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| Titel |
Boreal forest fire emissions in fresh Canadian smoke plumes: C1-C10 volatile organic compounds (VOCs), CO2, CO, NO2, NO, HCN and CH3CN |
| VerfasserIn |
I. J. Simpson, S. K. Akagi, B. Barletta, N. J. Blake, Y. Choi, G. S. Diskin, A. Fried, H. E. Fuelberg, S. Meinardi, F. S. Rowland, S. A. Vay, A. J. Weinheimer, P. O. Wennberg, P. Wiebring, A. Wisthaler, M. Yang, R. J. Yokelson, D. R. Blake |
| 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 ; 11, no. 13 ; Nr. 11, no. 13 (2011-07-07), S.6445-6463 |
| Datensatznummer |
250009896
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| Publikation (Nr.) |
 copernicus.org/acp-11-6445-2011.pdf |
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| Zusammenfassung |
| Boreal regions comprise about 17 % of the global land area, and they both
affect and are influenced by climate change. To better understand boreal
forest fire emissions and plume evolution, 947 whole air samples were
collected aboard the NASA DC-8 research aircraft in summer 2008 as part of
the ARCTAS-B field mission, and analyzed for 79 non-methane volatile organic
compounds (NMVOCs) using gas chromatography. Together with simultaneous
measurements of CO2, CO, CH4, CH2O, NO2, NO, HCN and
CH3CN, these measurements represent the most comprehensive assessment
of trace gas emissions from boreal forest fires to date. Based on 105 air
samples collected in fresh Canadian smoke plumes, 57 of the 80 measured
NMVOCs (including CH2O) were emitted from the fires, including 45
species that were quantified from boreal forest fires for the first time.
After CO2, CO and CH4, the largest emission factors (EFs) for
individual species were formaldehyde (2.1 ± 0.2 g kg−1), followed
by methanol, NO2, HCN, ethene, α-pinene, β-pinene, ethane, benzene,
propene, acetone and CH3CN. Globally, we estimate that boreal forest
fires release 2.4 ± 0.6 Tg C yr−1 in the form of NMVOCs, with
approximately 41 % of the carbon released as C1-C2 NMVOCs and
21 % as pinenes. These are the first reported field measurements of
monoterpene emissions from boreal forest fires, and we speculate that the
pinenes, which are relatively heavy molecules, were detected in the fire
plumes as the result of distillation of stored terpenes as the vegetation is
heated. Their inclusion in smoke chemistry models is expected to improve
model predictions of secondary organic aerosol (SOA) formation. The
fire-averaged EF of dichloromethane or CH2Cl2, (6.9 ± 8.6) × 10−4 g kg−1, was not significantly different from zero
and supports recent findings that its global biomass burning source appears
to have been overestimated. Similarly, we found no evidence for emissions of
chloroform (CHCl3) or methyl chloroform (CH3CCl3) from boreal
forest fires. The speciated hydrocarbon measurements presented here show the
importance of carbon released by short-chain NMVOCs, the strong contribution
of pinene emissions from boreal forest fires, and the wide range of compound
classes in the most abundantly emitted NMVOCs, all of which can be used to
improve biomass burning inventories in local/global models and reduce
uncertainties in model estimates of trace gas emissions and their impact on
the atmosphere. |
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