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| Titel |
Precipitation effects of giant cloud condensation nuclei artificially introduced into stratocumulus clouds |
| VerfasserIn |
E. Jung, B. A. Albrecht, H. H. Jonsson, Y.-C. Chen, J. H. Seinfeld, A. Sorooshian, A. R. Metcalf, S. Song, M. Fang, L. M. Russell |
| 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 ; 15, no. 10 ; Nr. 15, no. 10 (2015-05-22), S.5645-5658 |
| Datensatznummer |
250119747
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| Publikation (Nr.) |
 copernicus.org/acp-15-5645-2015.pdf |
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| Zusammenfassung |
| To study the effect of giant cloud condensation nuclei (GCCN) on
precipitation processes in stratocumulus clouds, 1–10 μm diameter
salt particles (salt powder) were released from an aircraft while flying near
the cloud top on 3 August 2011 off the central coast of California. The
seeded area was subsequently sampled from the aircraft that was equipped with
aerosol, cloud, and precipitation probes and an upward-facing cloud radar.
During post-seeding sampling, made 30–60 min after seeding, the mean cloud
droplet size increased, the droplet number concentration decreased, and large
drop (e.g., diameter larger than 10 μm) concentration increased.
Average drizzle rates increased from about 0.05 to 0.20 mm h−1, and
the liquid water path decreased from about 52 to 43 g m−2. Strong
radar returns associated with drizzle were observed on the post-seeding
cloud-base level-leg flights and were accompanied by a substantial depletion
of the cloud liquid water content. The changes were large enough to suggest
that the salt particles with concentrations estimated to be 10−2 to
10-4 cm−3 resulted in a four-fold increase in the cloud-base
rainfall rate and depletion of the cloud water due to rainout. In contrast, a
case is shown where the cloud was already precipitating (on 10 August) and
the effect of adding GCCN to the cloud was insignificant. |
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