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| Titel |
Submicron particle mass concentrations and sources in the Amazonian wet season (AMAZE-08) |
| VerfasserIn |
Q. Chen, D. K. Farmer, L. V. Rizzo, T. Pauliquevis, M. Kuwata, T. G. Karl, A. Guenther, J. D. Allan, H. Coe, M. O. Andreae, U. Pöschl, J. L. Jimenez, P. Artaxo, S. T. Martin |
| 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 ; 15, no. 7 ; Nr. 15, no. 7 (2015-04-02), S.3687-3701 |
| Datensatznummer |
250119613
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| Publikation (Nr.) |
 copernicus.org/acp-15-3687-2015.pdf |
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| Zusammenfassung |
| Real-time mass spectra of the non-refractory species in submicron aerosol
particles were recorded in a tropical rainforest in the central Amazon Basin
during the wet season from February to March 2008, as a part of the
Amazonian Aerosol Characterization Experiment (AMAZE-08). Organic material
accounted on average for more than 80% of the non-refractory submicron
particle mass concentrations during the period of measurements. There was
insufficient ammonium to neutralize sulfate. In this acidic, isoprene-rich,
HO2-dominant environment, positive-matrix factorization of the time
series of particle mass spectra identified four statistical factors to
account for the 99% of the variance in the signal intensities of the organic
constituents. The first factor was identified as associated with regional
and local pollution and labeled "HOA" for its hydrocarbon-like
characteristics. A second factor was associated with long-range transport
and labeled "OOA-1" for its oxygenated characteristics. A third factor,
labeled "OOA-2," was implicated as associated with the reactive uptake of
isoprene oxidation products, especially of epoxydiols to acidic haze, fog, or
cloud droplets. A fourth factor, labeled "OOA-3," was consistent with
an association with the fresh production of secondary organic material (SOM)
by the mechanism of gas-phase oxidation of biogenic volatile organic
precursors followed by gas-to-particle conversion of the oxidation products.
The suffixes 1, 2, and 3 on the OOA labels signify ordinal ranking with
respect to the extent of oxidation represented by the factor. The process of
aqueous-phase oxidation of water-soluble products of gas-phase
photochemistry might also have been associated to some extent with the OOA-2
factor. The campaign-average factor loadings had a ratio of 1.4:1 for
OOA-2 : OOA-3, suggesting the comparable importance of particle-phase compared
to gas-phase pathways for the production of SOM during the study period. |
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