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| Titel |
Detection and characterization of volcanic ash plumes over Lille during the Eyjafjallajökull eruption |
| VerfasserIn |
A. Mortier, P. Goloub, T. Podvin, C. Deroo, A. Chaikovsky, N. Ajtai, L. Blarel, D. Tanré, Y. Derimian |
| 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 ; 13, no. 7 ; Nr. 13, no. 7 (2013-04-04), S.3705-3720 |
| Datensatznummer |
250018574
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| Publikation (Nr.) |
 copernicus.org/acp-13-3705-2013.pdf |
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| Zusammenfassung |
| Routine sun-photometer and micro-lidar measurements were performed in Lille,
northern France, in April and May 2010 during the Eyjafjallajökull
volcanic eruption. The impact of such an eruption emphasized significance of
hazards for human activities and importance of observations of the volcanic
aerosol particles. This paper presents the main results of a joint
micro-lidar/sun-photometer analysis performed in Lille, where volcanic ash
plumes were observed during at least 22 days, whenever weather conditions
permitted. Aerosol properties retrieved from automatic sun-photometer
measurements (AERONET) were strongly changed during the volcanic aerosol
plumes transport over Lille. In most cases, the aerosol optical depth (AOD)
increased, whereas Ångström exponent decreased, thus indicating
coarse-mode dominance in the volume size distribution. Moreover, the non-spherical
fraction retrieved by AERONET significantly increased. The real part of the
complex refractive index was up to 1.55 at 440 nm during the eruption,
compared to background data of about 1.46 before the eruption. Collocated
lidar data revealed that several aerosol layers were present between 2 and
5 km, all originating from the Iceland region as confirmed by
backward trajectories. The volcanic ash AOD was derived from lidar
extinction profiles and sun-photometer AOD, and its maximum was estimated
around 0.37 at 532 nm on 18 April 2010. This value was observed at an
altitude of 1700 m and corresponds to an ash mass concentration (AMC)
slightly higher than 1000 μg m−3 (±50%). An effective lidar
ratio of ash particles of 48 sr was retrieved at 532 nm for 17 April during
the early stages of the eruption, a value which agrees with several other
studies carried out on this topic. Even though the accuracy of the
retrievals is not as high as that obtained from reference multiwavelength
lidar systems, this study demonstrates the opportunity of micro-lidar and
sun-photometer joint data processing for deriving volcanic AMC. It also
outlines the fact that a network of combined micro-lidars and
sun photometers can be a powerful tool for routine monitoring of aerosols,
especially in the case of such hazardous volcanic events. |
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