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| Titel |
A modeling analysis of a heavy air pollution episode occurred in Beijing |
| VerfasserIn |
X. An, T. Zhu, Z. Wang, C. Li, Y. Wang |
| 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 ; 7, no. 12 ; Nr. 7, no. 12 (2007-06-18), S.3103-3114 |
| Datensatznummer |
250005082
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| Publikation (Nr.) |
 copernicus.org/acp-7-3103-2007.pdf |
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| Zusammenfassung |
| The concentrations of fine particulate matter (PM) and ozone in Beijing
often exceed healthful levels in recent years, therefore China is to taking
steps to improve Beijing's air quality for the 2008 Olympic Games. In this
paper, the Models-3 Community Multiscale Air Quality (CMAQ) Modeling System
was used to investigate a heavy air pollution episode in Beijing during
3–7 April 2005 to obtain the basic information of how heavy air pollution
formed and the contributions of local sources and surround emissions. The
modeling domain covered from East Asia with four nested grids with 81 to 3 km
horizontal resolution focusing on urban Beijing. This was coupled with a
regional emissions inventory with a 10 km resolution and a local 1 km
Beijing emissions database. The trend of predicted concentrations of various
pollutants agreed reasonably well with the observations and captured the
main features of this heavy pollution episode. The simulated column
concentration distribution of PM was correlated well with the MODIS remote
sensing products. Control runs with and without Beijing emissions were
conducted to quantify the contributions of non-Beijing sources (NBS) to the
Beijing local air pollution. The contributions of NBS to each species
differed spatially and temporally with the order of PM2.5>PM10>SO2>
soil for this episode. The percentage contribution of NBS
to fine particle (PM2.5) in Beijing was averaged about 39%, up to
53% at the northwest of urban Beijing and only 15% at southwest. The
spatial distribution of NBS contributions for PM10 was similar to that
for PM2.5, with a slightly less average percentage of about 30%. The
average NBS contributions for SO2 and soil (diameter between
2.5 μm and 10 μm) were 18% and 10%. In addition, the pollutant
transport flux was calculated and compared at different levels to
investigate transport pathway and magnitude. It was found that the NBS
contribution correlated with the transport flux, contributing 60% of
PM10 concentration in Beijing at the time of transport flux peak during
a strong episode with a transport path from southwest to northeast. |
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