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| Titel |
Cloud condensation nuclei measurements in the marine boundary layer of the Eastern Mediterranean: CCN closure and droplet growth kinetics |
| VerfasserIn |
A. Bougiatioti, C. Fountoukis, N. Kalivitis, S. N. Pandis, A. Nenes, N. Mihalopoulos |
| 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 ; 9, no. 18 ; Nr. 9, no. 18 (2009-09-24), S.7053-7066 |
| Datensatznummer |
250007647
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| Publikation (Nr.) |
 copernicus.org/acp-9-7053-2009.pdf |
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| Zusammenfassung |
| Measurements of cloud condensation nuclei (CCN) concentrations (cm−3)
between 0.2 and 1.0% supersaturation, aerosol size distribution and
chemical composition were performed at a remote marine site in the eastern
Mediterranean, from September to October 2007 during the FAME07 campaign.
Most of the particles activate at ~0.6% supersaturation,
characteristic of the aged nature of the aerosol sampled. Application of
Köhler theory, using measurements of bulk composition, size
distribution, and assuming that organics are insoluble resulted in agreement
between predicted and measured CCN concentrations within 7±11% for
all supersaturations, with a tendency for CCN underprediction
(16±6%; r2=0.88) at the lowest supersaturations (0.21%). Including
the effects of the water-soluble organic fraction (which represent around
70% of the total organic content) reduces the average underprediction bias at the
low supersaturations, resulting in a total closure error of 0.6±6%.
Using threshold droplet growth analysis, the growth kinetics of ambient CCN
is consistent with NaCl calibration experiments; hence the presence of aged
organics does not suppress the rate of water uptake in this environment. The
knowledge of the soluble salt fraction is sufficient for the description of
the CCN activity in this area. |
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