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| Titel |
Observations of nonmethane organic compounds during ARCTAS - Part 1: Biomass burning emissions and plume enhancements |
| VerfasserIn |
R. S. Hornbrook, D. R. Blake, G. S. Diskin, A. Fried, H. E. Fuelberg, S. Meinardi, T. Mikoviny, D. Richter, G. W. Sachse, S. A. Vay, J. Walega, P. Weibring, A. J. Weinheimer, C. Wiedinmyer, A. Wisthaler, A. Hills, D. D. Riemer, E. C. Apel |
| 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. 21 ; Nr. 11, no. 21 (2011-11-09), S.11103-11130 |
| Datensatznummer |
250010177
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| Publikation (Nr.) |
 copernicus.org/acp-11-11103-2011.pdf |
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| Zusammenfassung |
| Mixing ratios of a large number of nonmethane organic compounds (NMOCs) were
observed by the Trace Organic Gas Analyzer (TOGA) on board the NASA DC-8 as
part of the Arctic Research of the Composition of the Troposphere from
Aircraft and Satellites (ARCTAS) field campaign. Many of these NMOCs were
observed concurrently by one or both of two other NMOC measurement
techniques on board the DC-8: proton-transfer-reaction mass spectrometry
(PTR-MS) and whole air canister sampling (WAS). A comparison of these
measurements to the data from TOGA indicates good agreement for the majority
of co-measured NMOCs. The ARCTAS study, which included both spring and
summer deployments, provided opportunities to sample a large number of
biomass burning (BB) plumes with origins in Asia, California and central
Canada, ranging from very recent emissions to plumes aged one week or more.
For this analysis, BB smoke interceptions were grouped by flight, source
region and, in some cases, time of day, generating 40 identified BB plumes
for analysis. Normalized excess mixing ratios (NEMRs) to CO were determined
for each of the 40 plumes for up to 19 different NMOCs or NMOC groups.
Although the majority of observed NEMRs for individual NMOCs or NMOC groups
were in agreement with previously-reported values, the observed NEMRs to CO
for ethanol, a rarely quantified gas-phase trace gas, ranged from values
similar to those previously reported, to up to an order of magnitude
greater. Notably, though variable between plumes, observed NEMRs of
individual light alkanes are highly correlated within BB emissions,
independent of estimated plume ages. BB emissions of oxygenated NMOC were
also found to be often well-correlated. Using the NCAR Master Mechanism
chemical box model initialized with concentrations based on two observed
scenarios, fresh Canadian BB and fresh Californian BB, decreases are
predicted for the low molecular weight carbonyls (i.e. formaldehyde,
acetaldehyde, acetone and methyl ethyl ketone, MEK) and alcohols (i.e.
methanol and ethanol) as the plumes evolve in time, i.e. the production of
these compounds is less than the chemical loss. Comparisons of the modeled
NEMRs to the observed NEMRs from BB plumes estimated to be three days in age
or less indicate overall good agreement. |
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