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| Titel |
Variation of particle number size distributions and chemical compositions at the urban and downwind regional sites in the Pearl River Delta during summertime pollution episodes |
| VerfasserIn |
D. L. Yue, M. Hu, Z. J. Wu, S. Guo, M. T. Wen, A. Nowak, B. Wehner, A. Wiedensohler, N. Takegawa, Y. Kondo, X. S. Wang, Y. P. Li, L. M. Zeng, Y. H. Zhang |
| 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. 19 ; Nr. 10, no. 19 (2010-10-07), S.9431-9439 |
| Datensatznummer |
250008810
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| Publikation (Nr.) |
 copernicus.org/acp-10-9431-2010.pdf |
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| Zusammenfassung |
| In order to characterize the features of particulate pollution in the Pearl
River Delta (PRD) in the summer, continuous measurements of particle number
size distributions and chemical compositions were simultaneously performed
at Guangzhou urban site (GZ) and Back-garden downwind regional site (BG) in
July 2006. Particle number concentration from 20 nm to 10 μm at BG was
(1.7±0.8)×104 cm−3, about 40% lower than that at
GZ, (2.9±1.1)×104 cm−3. The total particle volume
concentration at BG was 94±34 μm3 cm−3, similar to that
at GZ, 96±43 μm3 cm−3. More 20–100 nm particles,
significantly affected by the traffic emissions, were observed at GZ, while
100–660 nm particle number concentrations were similar at both sites as they
are more regional. PM2.5 values were similar at GZ (69±43 μg m−3)
and BG (69±58 μg m−3) with R2 of 0.71 for the
daily average PM2.5 at these two sites, indicating the fine particulate
pollution in the PRD region to be regional. Two kinds of pollution episodes,
the accumulation pollution episode and the regional transport pollution
episode, were observed. Fine particles over 100 nm dominated both number and
volume concentrations of total particles during the late periods of these
pollution episodes. Accumulation and secondary transformation are the main
reasons for the nighttime accumulation pollution episode. SO42−,
NO3− accounted for about 60% in 100–660 nm
particle mass and PM2.5 increase. When south or southeast wind
prevailed in the PRD region, regional transport of pollutants took place.
Regional transport contributed about 30% to fine particulate pollution at
BG during a regional transport case. Secondary transformation played an
important role during regional transport, causing higher increase rates of
secondary ions in PM1.0 than other species and shifting the peaks of
sulfate and ammonium mass size distributions to larger sizes.
SO42−, NO3−, and NH4+
accounted for about
70% and 40% of PM1.0 and PM2.5, respectively. |
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