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| Titel |
Brown carbon absorption linked to organic mass tracers in biomass burning particles |
| VerfasserIn |
D. A. Lack, R. Bahreini, J. M. Langridge, J. B. Gilman, A. M. Middlebrook |
| 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 ; 13, no. 5 ; Nr. 13, no. 5 (2013-03-01), S.2415-2422 |
| Datensatznummer |
250018462
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| Publikation (Nr.) |
 copernicus.org/acp-13-2415-2013.pdf |
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| Zusammenfassung |
| Traditional gas and particle phase chemical markers used to identify the
presence of biomass burning (BB) emissions were measured for a large forest
fire near Boulder, Colorado. Correlation of the organic matter mass
spectroscopic m/z 60 with measured particle light absorption properties found
no link at 532 nm, and a strong correlation at 404 nm. Non-black carbon
absorption at 404 nm was well correlated to the ratio of the mass fractions
of particulate organic matter (POM) that was m/z 60 (f60) to m/z 44
(f44). The f60 to f44 ratio did not fully explain the
variability in non-BC absorption, due to contributions of brown carbon (BrC)
absorption and absorption due to internal mixing of POM with black carbon
(BC). The absorption Ångstrom exponent (ÅAbs) showed a good correlation
to f60/f44; however the best correlation resulted from the mass
absorption efficiency (MAE) of BrC at 404 nm (MAEPOM-404 nm) and
f60/f44. This result indicates that the absorption of POM at low
visible and UV wavelengths is linked to emissions of organic matter that
contribute to the m/z 60 mass fragment, although they do not contribute to 532 nm
absorption. m/z 60 is often attributed to levoglucosan and related compounds.
The linear relationship between MAEPOM-404 nm and f60/f44
suggests that the strength of BrC absorption for this fire can be predicted
by emissions of f60-related organic matter. |
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