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| Titel |
Chemical characterization of submicron aerosol and particle growth events at a national background site (3295 m a.s.l.) on the Tibetan Plateau |
| VerfasserIn |
W. Du, Y. L. Sun, Y. S. Xu, Q. Jiang, Q. Q. Wang, W. Yang, F. Wang, Z. P. Bai, X. D. Zhao, Y. C. Yang |
| 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. 18 ; Nr. 15, no. 18 (2015-09-29), S.10811-10824 |
| Datensatznummer |
250120062
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| Publikation (Nr.) |
 copernicus.org/acp-15-10811-2015.pdf |
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| Zusammenfassung |
| Atmospheric aerosols exert highly uncertain impacts on radiative forcing and
also have detrimental effects on human health. While aerosol particles are
widely characterized in megacities in China, aerosol composition, sources
and particle growth in rural areas in the Tibetan Plateau remain less
understood. Here we present the results from an autumn study that was
conducted from 5 September to 15 October 2013 at a national background
monitoring station (3295 m a.s.l.) in the Tibetan Plateau. The submicron
aerosol composition and particle number size distributions were measured in
situ with an Aerodyne Aerosol Chemical Speciation Monitor (ACSM) and a
Scanning Mobility Particle Sizer (SMPS). The average mass concentration of
submicron aerosol (PM1) is 11.4 μg m−3 (range:
1.0–78.4 μg m−3) for the entire study, which is much lower than
observed at urban and rural sites in eastern China. Organics dominated
PM1, accounting for 43 % on average, followed by sulfate (28 %) and
ammonium (11 %). Positive Matrix Factorization analysis of ACSM organic
aerosol (OA) mass spectra identified an oxygenated OA (OOA) and a biomass
burning OA (BBOA). The OOA dominated OA composition, accounting for 85 % on
average, 17 % of which was inferred from aged BBOA. The BBOA contributed a
considerable fraction of OA (15 %) due to the burning of cow dung and
straw in September. New particle formation and growth events were
frequently observed (80 % of time) throughout the study. The average
particle growth rate is 2.0 nm h−1 (range: 0.8–3.2 nm h−1).
By linking the evolution of particle number size distribution to aerosol
composition, we found an elevated contribution of organics during particle
growth periods and also a positive relationship between the growth rate and
the fraction of OOA in OA, which potentially indicates an important role of
organics in particle growth in the Tibetan Plateau. |
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