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| Titel |
A case study of the highly time-resolved evolution of aerosol chemical and optical properties in urban Shanghai, China |
| VerfasserIn |
Y. Huang, L. Li, J. Li, X. Wang, H. Chen, J. Chen, X. Yang, D. S. Gross, H. Wang, L. Qiao, C. Chen |
| 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. 8 ; Nr. 13, no. 8 (2013-04-17), S.3931-3944 |
| Datensatznummer |
250018590
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| Publikation (Nr.) |
 copernicus.org/acp-13-3931-2013.pdf |
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| Zusammenfassung |
| Characteristics of the chemical and optical properties of aerosols in urban
Shanghai and their relationship were studied over a three-day period in
October 2011. A suite of real-time instruments, including an Aerosol
Time-Of-Flight Mass Spectrometer (ATOFMS), a Monitor for AeRosols and GAses
(MARGA), a Cavity Ring Down Spectrometer (CRDS), a nephelometer and a
Scanning Mobility Particle Sizer (SMPS), was employed to follow the quick
changes of the aerosol properties within the 72 h sampling period. The
origin of the air mass arriving in Shanghai during this period shifted from
the East China Sea to the northwest area of China, offering a unique
opportunity to observe the evolution of aerosols influenced by regional
transport from the most polluted areas in China. According to the
meteorological conditions and temporal characterizations of the chemical and
optical properties, the sampling period was divided into three periods.
During Period 1 (00:00–23:00 LT, 13 October), the aerosols in urban Shanghai were
mainly fresh and the single scattering albedo varied negatively with the
emission of elemental carbon, indicating that local sources dominated.
Period 2 (23:00 LT on 13 October to 10:00 LT on 15 October) was impacted by regionally
transported pollutants and had the highest particulate matter (PM) mass
loading and the lowest particle acidity, characterized by large fractions of
aged particles and high secondary ion (nitrate, sulfate and ammonium) mass
concentrations. Comparison between ATOFMS particle acidity and quantitative
particle acidity by MARGA indicated the significance of semi-quantitative
calculation in ATOFMS. Two sub-periods were identified in Period 2 based on
the scattering efficiency of PM1 mass. Period 3 (from 10:00 LT on 15 October
to 00:00 LT on 16 October) had a low PM1/PM10 ratio and a new particle
formation event. The comparison of these sub-periods highlights the
influence of particle mixing state on aerosol optical properties. We
directly observed the influence of regionally transported pollutants on
local aerosol properties and demonstrate that the PM mass extinction
efficiency is largely determined by the mixing states of the aerosol. |
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