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| Titel |
Ice nuclei properties within a Saharan dust event at the Jungfraujoch in the Swiss Alps |
| VerfasserIn |
C. Chou, O. Stetzer, E. Weingärtner, Z. Jurányi, Z. A. Kanji, U. Lohmann |
| 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 ; 11, no. 10 ; Nr. 11, no. 10 (2011-05-20), S.4725-4738 |
| Datensatznummer |
250009751
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| Publikation (Nr.) |
 copernicus.org/acp-11-4725-2011.pdf |
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| Zusammenfassung |
| The new portable ice nucleation chamber (PINC) developed by the Institute for
Atmospheric and Climate Sciences of ETH Zurich was operated during two
measurement campaigns at the high alpine research station Jungfraujoch
situated at 3580 m a.s.l, in March and June 2009. During this time of the
year, a high probability of Saharan dust events (SDE) at the Jungfraujoch has
been observed. We used an impactor with a cutoff size of 1 μm
aerodynamic diameter and operated the system at −31 °C and
relative humidities of 127 % and 91 % with respect to ice and water,
respectively. Investigation of the ambient number concentration of ice nuclei
(IN) in the deposition nucleation mode and during a SDE in the free
troposphere is reported. The results discussed in this paper are the first
continuous IN measurements over a period of several days at the Jungfraujoch.
The average IN concentration found during the campaign in March was 8
particles per liter whereas during the campaign in June, the average number
concentration was higher up to 14 particles per liter. Two SDEs were detected
on 15 and 16 June 2009. Our measurements show that the SDEs had IN number
concentration up to several hundreds per liter. We found the best correlation
between the number concentration of the larger particle fraction measured by
an optical particle counter and the IN number concentration during a Saharan
dust event. This correlation factor is higher for particles larger than 0.5 μm
meaning that a higher concentration of larger particles induced
higher IN number concentration. No correlation could be found between the
black carbon mass concentration and the variations in IN number
concentration. |
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