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Titel |
Highly time-resolved chemical characterization of atmospheric submicron particles during 2008 Beijing Olympic Games using an Aerodyne High-Resolution Aerosol Mass Spectrometer |
VerfasserIn |
X.-F. Huang, L.-Y. He, M. Hu, M. R. Canagaratna, Y. Sun, Q. Zhang, T. Zhu, L. Xue, L.-W. Zeng, X.-G. Liu, Y.-H. Zhang, J. T. Jayne, N. L. Ng, D. R. Worsnop |
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 ; 10, no. 18 ; Nr. 10, no. 18 (2010-09-24), S.8933-8945 |
Datensatznummer |
250008788
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Publikation (Nr.) |
copernicus.org/acp-10-8933-2010.pdf |
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Zusammenfassung |
As part of Campaigns of Air Quality Research in Beijing and Surrounding
Region-2008 (CAREBeijing-2008), an Aerodyne High-Resolution Time-of-Flight
Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed in urban Beijing to
characterize submicron aerosol particles during the time of 2008 Beijing
Olympic Games and Paralympic Games (24 July to 20 September 2008). The
campaign mean PM1 mass concentration was 63.1 ± 39.8 μg m−3;
the mean composition consisted of organics (37.9%), sulfate
(26.7%), ammonium (15.9%), nitrate (15.8%), black carbon (3.1%),
and chloride (0.87%). The average size distributions of the species
(except BC) were all dominated by an accumulation mode peaking at about 600 nm in
vacuum aerodynamic diameter, and organics was characterized by an
additional smaller mode extending below 100 nm. Positive Matrix
Factorization (PMF) analysis of the high resolution organic mass spectral
dataset differentiated the organic aerosol into four components, i.e.,
hydrocarbon-like (HOA), cooking-related (COA), and two oxygenated organic
aerosols (OOA-1 and OOA-2), which on average accounted for 18.1, 24.4, 33.7
and 23.7% of the total organic mass, respectively. The HOA was identified
to be closely associated with primary combustion sources, while the COA mass
spectrum and diurnal pattern showed similar characteristics to that measured
for cooking emissions. The OOA components correspond to aged secondary
organic aerosol. Although the two OOA components have similar elemental
(O/C, H/C) compositions, they display differences in mass spectra and time
series which appear to correlate with the different source regions sampled
during the campaign. Back trajectory clustering analysis indicated that the
southerly air flows were associated with the highest PM1 pollution
during the campaign. Aerosol particles in southern airmasses were especially
rich in inorganic and oxidized organic species. Aerosol particles in
northern airmasses contained a large fraction of primary HOA and COA
species, probably due to stronger influences from local emissions. The
lowest concentration levels for all major species were obtained during the
Olympic game days (8 to 24 August 2008), possibly due to the effects of
both strict emission controls and favorable meteorological conditions. |
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