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| Titel |
Measurements of the relation between aerosol properties and microphysics and chemistry of low level liquid water clouds in Northern Finland |
| VerfasserIn |
H. Lihavainen, V.-M. Kerminen, M. Komppula, A.-P. Hyvärinen, J. Laakia, S. Saarikoski, U. Makkonen, N. Kivekäs, R. Hillamo, M. Kulmala  , Y. Viisanen |
| 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 ; 8, no. 23 ; Nr. 8, no. 23 (2008-12-01), S.6925-6938 |
| Datensatznummer |
250006473
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| Publikation (Nr.) |
 copernicus.org/acp-8-6925-2008.pdf |
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| Zusammenfassung |
| Physical and chemical properties of boundary layer clouds, together with
relevant aerosol properties, were investigated during the first Pallas Cloud
Experiment (First Pace) conducted in northern Finland between 20 October and
9 November 2004. Two stations located 6 km apart from each other at
different altitudes were employed in measurements. The low-altitude station
was always below the cloud layer, whereas the high-altitude station was
inside clouds about 75% of the time during the campaign. Direct measurements
of cloud droplet populations showed that our earlier approach of determining
cloud droplet residual particle size distributions and corresponding
activated fractions using continuous aerosol number size distribution
measurements at the two stations is valid, as long as the cloud events are
carefully screened to exclude precipitating clouds and to make sure the same
air mass has been measured at both stations. We observed that a
non-negligible fraction of cloud droplets originated from Aitken mode
particles even at moderately-polluted air masses. We found clear evidence on
first indirect aerosol effect on clouds but demonstrated also that no simple
relation between the cloud droplet number concentration and aerosol particle
number concentration exists for this type of clouds. The chemical composition
of aerosol particles was dominated by particulate organic matter (POM) and
sulphate in continental air masses and POM, sodium and chlorine in marine air
masses. The inorganic composition of cloud water behaved similarly to that of
the aerosol phase and was not influenced by inorganic trace gases. |
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