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| Titel |
Characteristics of atmospheric ammonia over Beijing, China |
| VerfasserIn |
Z. Y. Meng, W. L. Lin, X. M. Jiang, P. Yan, Y. Wang, Y. M. Zhang, X. F. Jia, X. L. Yu |
| 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 ; 11, no. 12 ; Nr. 11, no. 12 (2011-06-29), S.6139-6151 |
| Datensatznummer |
250009877
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| Publikation (Nr.) |
 copernicus.org/acp-11-6139-2011.pdf |
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| Zusammenfassung |
| Continuous measurements of atmospheric ammonia (NH3) were conducted
using Ogawa passive samplers from February 2008 to July 2010 at an urban
site and from January 2007 to July 2010 at a rural site in Beijing, China.
NH4+ in fine particles was also collected at the rural site during
2008–2009. The field comparison between the Ogawa passive samplers and an
active analyzer for NH3 conducted at the urban site assures the quality
and accuracy of the measurements. The concentrations of NH3 at the
urban site ranged from 0.7 to 85.1 ppb, with the annual average of 18.5 ± 13.8
and 23.5 ± 18.0 ppb in 2008 and 2009, respectively. The
NH3 concentrations at the rural site were lower than those at urban site, and
varied from 0.8 to 42.9 ppb, with the annual average of 4.5 ± 4.6,
6.6 ± 7.0 and 7.1 ± 3.5 ppb in 2007, 2008 and 2009, respectively. The
data showed marked seasonal variations at both sites. The results emphasized
traffic to be a significant source of NH3 concentrations in winter in
urban areas of Beijing. This was illustrated by the strong correlations of
NH3 with the traffic related pollutants (NOx and CO) and also by the
bimodal diurnal cycle of NH3 concentrations that was synchronized with
traffic. Similar patterns were not observed during the summer, suggesting
other non-traffic sources became more important. At the rural site, the
daily NH4+ concentrations ranged from 0.10 to 36.53 μg m−3,
with an average of 7.03 μg m−3 from June 2008 to
December 2009. Monthly NH3 were significantly correlated with
NH4+ concentrations. Average monthly NH3/NH4+
ratios varied from 0.13 to 2.28, with an average of 0.73. NH4+ in PM2.5
was primarily associated with SO4−2 at the rural site. |
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