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| Titel |
Nanoparticles in boreal forest and coastal environment: a comparison of observations and implications of the nucleation mechanism |
| VerfasserIn |
K. Lehtipalo, M. Kulmala  , M. Sipilä, T. Petäjä, M. Vana, D. Ceburnis, R. Dupuy, C. O'Dowd |
| 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. 15 ; Nr. 10, no. 15 (2010-08-02), S.7009-7016 |
| Datensatznummer |
250008667
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| Publikation (Nr.) |
 copernicus.org/acp-10-7009-2010.pdf |
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| Zusammenfassung |
| The detailed mechanism of secondary new particle formation in the atmosphere
is still under debate. It is proposed that particle formation happens via
activation of 1–2 nm atmospheric neutral molecular clusters and/or large
molecules. Since traditional instrumentation does not reach these sizes, the
hypothesis has not yet been verified. By directly measuring particle size
distributions down to mobility diameters of about 1.3 nm with a pulse-height
CPC, we provide evidence of the nucleation mechanism in a coastal
environment (Mace Head, Ireland) and in a boreal forest (Hyytiälä,
Finland). In both places neutral sub-3 nm condensation nuclei (nano-CN) were
continuously present, even when no new particle formation was detected. In
Mace Head, however, the concentration of the nano-CN was far too low to
account for the particle formation rates during particle bursts. Thus the
results imply that at coastal sites new particle formation initiates, as
previously proposed, via homogenous nucleation from biogenic iodine vapors.
In contrast, activation of pre-existing nano-CN remains a possible
explanation in the boreal forest, but the observed concentrations are not
the limiting factor for the particle formation events. |
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