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Titel |
New-particle formation, growth and climate-relevant particle production in Egbert, Canada: analysis from 1 year of size-distribution observations |
VerfasserIn |
J. R. Pierce, D. M. Westervelt, S. A. Atwood, E. A. Barnes, 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 ; 14, no. 16 ; Nr. 14, no. 16 (2014-08-26), S.8647-8663 |
Datensatznummer |
250118976
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Publikation (Nr.) |
copernicus.org/acp-14-8647-2014.pdf |
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Zusammenfassung |
Aerosol particle nucleation, or new-particle formation, is the dominant
contributor to particle number in the atmosphere. However, these particles
must grow through condensation of low-volatility vapors without coagulating
with the larger, preexisting particles in order to reach climate-relevant
sizes (diameters larger than 50–100 nm), where the particles may affect
clouds and radiation. In this paper, we use 1 year of size-distribution
measurements from Egbert, Ontario, Canada to calculate the frequency of
regional-scale new-particle-formation events, new-particle-formation rates,
growth rates and the fraction of new particles that survive to reach
climate-relevant sizes. Regional-scale new-particle-formation events occur
on 14–31% of the days (depending on the stringency of the classification
criteria), with event frequency peaking in the spring and fall. New-particle-formation rates and growth rates are similar to those measured at other
midlatitude continental sites. We calculate that roughly half of the
climate-relevant particles (with diameters larger than 50–100 nm) at Egbert
are formed through new-particle-formation events. With the addition of
meteorological and SO2 measurements, we find that new-particle
formation at Egbert often occurs under synoptic conditions associated with
high surface pressure and large-scale subsidence that cause sunny conditions
and clean-air flow from the north and west. However, new-particle formation
also occurs when air flows from the polluted regions to the south and
southwest of Egbert. The new-particle-formation rates tend to be faster
during events under the polluted south/southwest flow conditions. |
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