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| Titel |
Insights into characteristics, sources, and evolution of submicron aerosols during harvest seasons in the Yangtze River delta region, China |
| VerfasserIn |
Y. J. Zhang, L. L. Tang, Z. Wang, H. X. Yu, Y. L. Sun, D. Liu, W. Qin, F. Canonaco, A. S. H. Prévôt, H. L. Zhang, H. C. Zhou |
| 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. 3 ; Nr. 15, no. 3 (2015-02-06), S.1331-1349 |
| Datensatznummer |
250119394
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| Publikation (Nr.) |
 copernicus.org/acp-15-1331-2015.pdf |
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| Zusammenfassung |
| Atmospheric submicron particulate matter (PM1) is one of the most
significant pollution components in China. Despite its current popularity in
the studies of aerosol chemistry, the characteristics, sources and evolution
of atmospheric PM1 species are still poorly understood in China,
particularly for the two harvest seasons, namely, the summer wheat harvest
and autumn rice harvest. An Aerodyne Aerosol Chemical Speciation Monitor
(ACSM) was deployed for online monitoring of PM1 components during
summer and autumn harvest seasons in urban Nanjing, in the Yangtze River
delta (YRD) region of China. PM1 components were shown to be dominated
by organic aerosol (OA, 39 and 41%) and nitrate (23 and 20%)
during the harvest seasons (the summer and autumn harvest). Positive matrix
factorization (PMF) analysis of the ACSM OA mass spectra resolved four OA
factors: hydrocarbon-like mixed with cooking-related OA (HOA + COA), fresh
biomass-burning OA (BBOA), oxidized biomass-burning-influenced OA (OOA-BB),
and highly oxidized OA (OOA); in particular the oxidized BBOA contributes
~80% of the total BBOA loadings. Both fresh and oxidized
BBOA exhibited apparent diurnal cycles with peak concentration at night,
when the high ambient relative humidity and low temperature facilitated the
partitioning of semi-volatile organic species into the particle phase. The
fresh BBOA concentrations for the harvests are estimated as BBOA = 15.1 × (m/z 60–0.26% × OA),
where m/z (mass-to-charge ratio) 60 is a marker for
levoglucosan-like species. The (BBOA + OOA-BB)/ΔCO, (ΔCO
is the CO minus background CO), decreases as a function of f44 (fraction of m/z 44 in OA signal), which might indicate that BBOA was oxidized
to less volatile OOA, e.g., more aged and low volatility OOA (LV-OOA) during
the aging process. Analysis of air mass back trajectories indicates that the
high BB pollutant concentrations are linked to the air masses from the
western (summer harvest) and southern (autumn harvest) areas. |
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