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| Titel |
Wet and dry deposition of atmospheric nitrogen at ten sites in Northern China |
| VerfasserIn |
Y. P. Pan, Y. S. Wang, G. Q. Tang, D. Wu |
| 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 ; 12, no. 14 ; Nr. 12, no. 14 (2012-07-25), S.6515-6535 |
| Datensatznummer |
250011341
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| Publikation (Nr.) |
 copernicus.org/acp-12-6515-2012.pdf |
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| Zusammenfassung |
| Emissions of reactive nitrogen (N) species can affect surrounding ecosystems
via atmospheric deposition. However, few long-term and multi-site
measurements have focused on both the wet and the dry deposition of
individual N species in large areas of Northern China. Thus, the magnitude
of atmospheric deposition of various N species in Northern China remains
uncertain. In this study, the wet and dry atmospheric deposition of
different N species was investigated during a three-year observation
campaign at ten selected sites in Northern China. The results indicate that
N deposition levels in Northern China were high with a ten-site, three-year
average of 60.6 kg N ha−1 yr−1. The deposition levels showed
spatial and temporal variation in the range of 28.5–100.4 kg N ha−1 yr−1.
Of the annual total deposition, 40% was deposited via
precipitation, and the remaining 60% was comprised of dry-deposited
forms. Compared with gaseous N species, particulate N species were not the
major contributor of dry-deposited N; they contributed approximately 10%
to the total flux. On an annual basis, oxidized species accounted for 21%
of total N deposition, thereby implying that other forms of gaseous N, such
as NH3, comprised a dominant portion of the total flux. The
contribution of NO3− to N deposition was enhanced in certain urban
and industrial areas, possibly due to the fossil fuse combustion. As
expected, the total N deposition in Northern China was significantly larger
than the values reported by national scale monitoring networks in Europe,
North America and East Asia because of high rates of wet deposition and
gaseous NH3 dry deposition. Taken together, these findings show that
NH3 emissions should be abated to mitigate high N deposition and
associated potential impacts on ecosystems in Northern China. The present
results improve our understanding of spatio-temporal variations of
magnitudes, pathways and species of deposited N in the target areas, and are
important not only to inform conservation and regulatory bodies but also to
initiate further detailed studies. Uncertainties among current observations
underscore the need to quantify the impact of vegetation on dry deposition
and to refine the simulation of dry deposition velocity. |
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