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| Titel |
Characteristics of regional new particle formation in urban and regional background environments in the North China Plain |
| VerfasserIn |
Z. B. Wang, M. Hu, J. Y. Sun, Z. J. Wu, D. L. Yue, X. J. Shen, Y. M. Zhang, X. Y. Pei, Y. F. Cheng, A. Wiedensohler |
| 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 ; 13, no. 24 ; Nr. 13, no. 24 (2013-12-20), S.12495-12506 |
| Datensatznummer |
250085898
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| Publikation (Nr.) |
 copernicus.org/acp-13-12495-2013.pdf |
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| Zusammenfassung |
| Long-term measurements of particle number size distributions were carried
out both at an urban background site (Peking University, PKU) and a regional
Global Atmospheric Watch station (Shangdianzi, SDZ) from March to November
in 2008. In total, 52 new particle formation (NPF) events were observed
simultaneously at both sites, indicating that this is a regional phenomenon
in the North China Plain. On average, the mean condensation sink value
before the nucleation events started was 0.025 s−1 in the urban
environment, which was 1.6 times higher than that at regional site. However,
higher particle formation and growth rates were observed at PKU (10.8 cm−3 s−1
and 5.2 nm h−1) compared with those at SDZ (4.9 cm−3 s−1
and 4.0 nm h−1). These results implied that precursors
were much more abundant in the polluted urban environment. Different from
the observations in cleaner environments, the background conditions of the
observed particle homogeneous nucleation events in the North China Plain
could be characterized as the co-existing of a stronger source of precursor
gases and a higher condensational sink of pre-existing aerosol particles.
Secondary aerosol formation following nucleation events results in an
increase of particle mass concentration, particle light scattering
coefficient, and cloud condensation nuclei (CCN) number concentration, with consequences on visibility,
radiative effects, and air quality. Typical regional NPF events with
significant particle nucleation rates and subsequent particle growth over a
sufficiently long time period at both sites were chosen to investigate the
influence of NPF on the number concentration of "potential" CCN. As a
result, the NPF and the subsequent condensable growth increased the CCN
number concentration in the North China Plain by factors in the range from
5.6 to 8.7. Moreover, the potential contribution of anthropogenic emissions
to the CCN number concentration was more than 50%, to which more
attention should be drawn in regional and global climate modeling,
especially in the polluted urban areas. |
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