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| Titel |
Submicron aerosols at thirteen diversified sites in China: size distribution, new particle formation and corresponding contribution to cloud condensation nuclei production |
| VerfasserIn |
J. F. Peng, M. Hu, Z. B. Wang, X. F. Huang, P. Kumar, Z. J. Wu, S. Guo, D. L. Yue, D. J. Shang, Z. Zheng, L. Y. He |
| 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 ; 14, no. 18 ; Nr. 14, no. 18 (2014-09-25), S.10249-10265 |
| Datensatznummer |
250119067
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| Publikation (Nr.) |
 copernicus.org/acp-14-10249-2014.pdf |
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| Zusammenfassung |
| Understanding the particle number size distributions in diversified
atmospheric environments is important in order to design mitigation
strategies related to submicron particles and their effects on regional air
quality, haze and human health. In this study, we conducted 15 different
field measurement campaigns between 2007 and 2011 at 13 individual sites in
China, including five urban sites, four regional
sites, three coastal/background sites
and one ship cruise measurement along eastern coastline of China. Size
resolved particles were measured in the 15–600 nm size range. The median
particle number concentrations (PNCs) were found to vary in the range of
1.1−2.2 × 104 cm−3 at urban sites,
0.8−1.5 × 104 cm−3 at regional sites,
0.4−0.6 × 104 cm−3 at coastal/background sites, and
0.5 × 104 cm−3 during cruise measurement. Peak diameters
at each of these sites varied greatly from 24 to 115 nm. Particles in the
15–25 nm (nucleation mode), 25–100 nm (Aitken mode) and 100–600 nm
(accumulation mode) range showed different characteristics at each sites,
indicating the features of primary emissions and secondary formation in these
diversified atmospheric environments. Diurnal variations show a build-up of
accumulation mode particles belt at regional sites, suggesting the
contribution of regional secondary aerosol pollution. Frequencies of new
particle formation (NPF) events were much higher at urban and regional sites
than at coastal sites and during cruise measurement. The average growth rates (GRs)
of nucleation mode particles were 8.0–10.9 nm h−1 at urban sites,
7.4–13.6 nm h−1 at regional sites and 2.8–7.5 nm h−1 at
coastal sites and during cruise measurement. The high gaseous precursors and strong
oxidation at urban and regional sites not only favored the formation of
particles, but also accelerated the growth rate of the nucleation mode
particles. No significant difference in condensation sink (CS) during NPF
days were observed among different site types, suggesting that the NPF events
in background areas were more influenced by the pollutant transport. In
addition, average contributions of NPF events to potential cloud condensation
nuclei (CCN) at 0.2% super-saturation in the afternoon of all sampling
days were calculated as 11% and 6% at urban sites and regional sites,
respectively. On the other hand, NPF events at coastal sites and during cruise
measurement had little impact on potential production of CCN. This study
provides a large data set of particle size distribution in diversified
atmosphere of China, improving our general understanding of emission,
secondary formation, new particle formation and corresponding CCN activity of
submicron aerosols in Chinese environments. |
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