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| Titel |
Impact of Gobi desert dust on aerosol chemistry of Xi'an, inland China during spring 2009: differences in composition and size distribution between the urban ground surface and the mountain atmosphere |
| VerfasserIn |
G. H. Wang, B. H. Zhou, C. L. Cheng, J. J. Cao, J. J. Li, J. J. Meng, J. Tao, R. J. Zhang, P. Q. Fu |
| 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. 2 ; Nr. 13, no. 2 (2013-01-22), S.819-835 |
| Datensatznummer |
250017603
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| Publikation (Nr.) |
 copernicus.org/acp-13-819-2013.pdf |
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| Zusammenfassung |
| Composition and size distribution of atmospheric aerosols
from Xi'an city (~400 m, altitude) in inland China during the
spring of 2009 including a massive dust event on 24 April were
measured and compared with a parallel measurement at the summit (2060 m,
altitude) of Mt. Hua, an alpine site nearby Xi'an. EC (elemental carbon), OC
(organic carbon) and major ions in the city were 2–22 times higher than
those on the mountaintop during the whole sampling period. Compared to that
in the non-dust period a sharp increase in OC was observed at both sites
during the dust period, which was mainly caused by an input of biogenic
organics from the Gobi desert. However, adsorption/heterogeneous reaction of
gaseous organics with dust was another important source of OC in the urban,
contributing 22% of OC in the dust event. In contrast to the mountain
atmosphere where fine particles were less acidic when dust was present, the
urban fine particles became more acidic in the dust event than in the
non-dust event, mainly due to enhanced heterogeneous formation of nitrate
and diluted NH3. Cl− and NO3− in the urban air during
the dust event significantly shifted toward coarse particles. Such
redistributions were further pronounced on the mountaintop when dust was
present, resulting in both ions almost entirely staying in coarse particles.
On the contrary, no significant spatial difference in size distribution of
SO42− was found between the urban ground surface and the mountain
atmosphere, which dominated in the fine mode (<2.1 μm) during
the nonevent and comparably distributed in the fine (<2.1 μm)
and coarse (>2.1 μm) modes during the dust event. |
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