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| Titel |
Atmospheric ice nucleators active ≥ -12 °C can be quantified on PM10 filters |
| VerfasserIn |
F. Conen, S. Henne, C. E. Morris, C. Alewell |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 5, no. 2 ; Nr. 5, no. 2 (2012-02-02), S.321-327 |
| Datensatznummer |
250002460
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| Publikation (Nr.) |
 copernicus.org/amt-5-321-2012.pdf |
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| Zusammenfassung |
| Small number concentrations render it difficult to quantify ice nucleators
(IN) in the atmosphere active at warm temperatures. A useful new method for
IN measurement based around filter collections is proposed. It makes use of
quartz filters used in 24 h PM10 monitoring (720 m3 air
sample). Small subsamples (1.8 mm diameter) from the effective filter area
and from the clean fringe (blank) are subjected to immersion freezing tests.
We applied the method to eight filters from the High Alpine Research Station
Jungfraujoch (3580 m above sea level) in the Swiss Alps. All filters carried
IN active at −7 °C and below. Number concentrations of IN active at
−8, −10, and −12 °C were on average 3.3, 10.7, and 17.2 m−3,
respectively. Several-fold larger numbers of IN active at ≥ −12 °C
per unit mass of PM10 were found in air masses influenced by Swiss and
southern German atmospheric boundary layer air, compared to a Saharan dust
event. In combination with data on PM10 mass, the method may be used to
re-construct time series of IN number concentrations. |
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