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| Titel |
Multi-wavelength Raman lidar observations of the Eyjafjallajökull volcanic cloud over Potenza, southern Italy |
| VerfasserIn |
L. Mona, A. Amodeo, G. D'Amico, A. Giunta, F. Madonna, G. Pappalardo |
| 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 ; 12, no. 4 ; Nr. 12, no. 4 (2012-02-29), S.2229-2244 |
| Datensatznummer |
250010749
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| Publikation (Nr.) |
 copernicus.org/acp-12-2229-2012.pdf |
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| Zusammenfassung |
During the eruption of Eyjafjallajökull in April–May 2010
multi-wavelength Raman lidar measurements were performed at the CNR-IMAA
Atmospheric Observatory (CIAO), whenever weather conditions permitted
observations. A methodology both for volcanic layer identification and
accurate aerosol typing has been developed. This methodology relies on the
multi-wavelength Raman lidar measurements and the support of long-term lidar
measurements performed at CIAO since 2000. The aerosol mask for lidar
measurements performed at CIAO during the 2010 Eyjafjallajökull eruption
has been obtained. Volcanic aerosol layers were observed in different
periods: 19–22 April, 27–29 April, 8–9 May, 13–14 May and 18–19 May. A
maximum aerosol optical depth of about 0.12–0.13 was observed on 20 April,
22:00 UTC and 13 May, 20:30 UTC. Volcanic particles were detected at low
altitudes, in the free troposphere and in the upper troposphere. Occurrences
of volcanic particles within the PBL were detected on 21–22 April and 13
May. A Saharan dust event was observed on 13–14 May: dust and volcanic
particles were simultaneously detected at CIAO at separated different
altitudes as well as mixed within the same layer.
Lidar ratios at 355 and 532 nm, the Ångström exponent at 355/532 nm,
the backscatter-related Ångström exponent at 532/1064 nm and the
particle linear depolarization ratio at 532 nm measured inside the detected
volcanic layers are discussed. The dependence of these quantities on
relative humidity has been investigated by using co-located microwave
profiler measurements. The measured values of these intensive parameters
indicate the presence of volcanic sulfates/continental mixed aerosol in the
volcanic aerosol layers observed at CIAO. In correspondence of the maxima
observed in the volcanic aerosol load on 19–20 April and 13 May, different
values of intensive parameters were observed. Apart from the occurrence of
sulfate aerosol, these values indicate also the presence of some ash which
is affected by the aging during transport over Europe. |
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