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| Titel |
Particle formation and growth at five rural and urban sites |
| VerfasserIn |
C.-H. Jeong, G. J. Evans, M. L. McGuire, R. Y.-W. Chang, J. P. D. Abbatt, K. Zeromskiene, M. Mozurkewich, S.-M. Li, W. R. Leaitch |
| 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 ; 10, no. 16 ; Nr. 10, no. 16 (2010-08-27), S.7979-7995 |
| Datensatznummer |
250008732
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| Publikation (Nr.) |
 copernicus.org/acp-10-7979-2010.pdf |
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| Zusammenfassung |
| Ultrafine particle (UFP) number and size distributions were simultaneously
measured at five urban and rural sites during the summer of 2007 in Ontario,
Canada as part of the Border Air Quality and Meteorology Study (BAQS-Met
2007). Particle formation and growth events at these five sites were
classified based on their strength and persistence as well as the variation
in geometric mean diameter. Regional nucleation and growth events and local
short-lived strong nucleation events were frequently observed at the
near-border rural sites, upwind of industrial sources. Surprisingly, the
particle number concentrations at one of these sites were higher than the
concentrations at a downtown site in a major city, despite its high traffic
density. Regional nucleation and growth events were favored during intense
solar irradiance and in less polluted cooler drier air. The most distinctive
regional particle nucleation and growth event during the campaign was
observed simultaneously at all five sites, which were up to 350 km apart.
Although the ultrafine particle concentrations and size distributions
generally were spatially heterogeneous across the region, a more uniform
spatial distribution of UFP across the five areas was observed during this
regional nucleation event. Thus, nucleation events can cover large regions,
contributing to the burden of UFP in cities and potentially to the
associated health impacts on urban populations. Local short-lived nucleation
events at the three near-border sites during this summer three-week campaign
were associated with high SO2, which likely originated from US and
Canadian industrial sources. Hence, particle formation in southwestern
Ontario appears to often be related to anthropogenic gaseous emissions but
biogenic emissions at times also contribute. Longer-term studies are needed
to help resolve the relative contributions of anthropogenic and biogenic
emissions to nucleation and growth in this region. |
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