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Titel |
Evaluation on the role of sulfuric acid in the mechanisms of new particle formation for Beijing case |
VerfasserIn |
Z. B. Wang, M. Hu, D. L. Yue, J. Zheng, R. Y. Zhang, A. Wiedensohler, Z. J. Wu, T. Nieminen, M. Boy |
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. 24 ; Nr. 11, no. 24 (2011-12-15), S.12663-12671 |
Datensatznummer |
250010271
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Publikation (Nr.) |
copernicus.org/acp-11-12663-2011.pdf |
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Zusammenfassung |
New particle formation (NPF) is considered as an important mechanism for
gas-to-particle transformation, and gaseous sulfuric acid is believed as a
crucial precursor. Up to now few field-based studies on nucleation mechanisms
and the role of sulfuric acid were conducted in China. In this study,
simultaneously measurements of particle number size distributions and gaseous
sulfuric acid concentrations were performed from July to September in 2008.
Totally, 22 new particle formation events were observed during the entire 85
campaign days. The results show that in the case of both higher source and
sink values, the result of the competition between source and sink is more
likely the key limiting factor to determine the observation of NPF events in
Beijing. The concentrations of gaseous sulfuric acid show good correlations
with freshly nucleated particles (N3-6 and formation rates (J3
and J1.5. The power-law relationship between H2SO4
concentration and N3-6 or J is adopted to explore the nucleation
mechanism. The exponents are showed a great range (from 1 to 7). More than
half of the NPF events exhibit an exponent larger than 2.5. For these cases,
the thermodynamic process works better than the activation or kinetic
nucleation theories to explain the nucleation events in urban atmosphere of
Beijing. |
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