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| Titel |
Monitoring of the Eyjafjallajökull volcanic aerosol plume over the Iberian Peninsula by means of four EARLINET lidar stations |
| VerfasserIn |
M. Sicard, J. L. Guerrero-Rascado, F. Navas-Guzmán, J. Preißler, F. Molero, S. Tomás, J. A. Bravo-Aranda, A. Comerón, F. Rocadenbosch, F. Wagner, M. Pujadas, L. Alados-Arboledas |
| 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. 6 ; Nr. 12, no. 6 (2012-03-30), S.3115-3130 |
| Datensatznummer |
250010952
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| Publikation (Nr.) |
 copernicus.org/acp-12-3115-2012.pdf |
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| Zusammenfassung |
| Lidar and sun-photometer measurements were performed intensively over the
Iberian Peninsula (IP) during the eruption of the Eyjafjallajökull volcano
(Iceland) in April–May 2010. The volcanic plume reached all the
IP stations for the first time on 5 May 2010. A thorough study of the event
was conducted for the period 5–8 May. Firstly, the spatial and temporal
evolution of the plume was described by means of lidar and sun-photometer
measurements supported with backtrajectories. The volcanic aerosol layers
observed over the IP were rather thin (<1000 m) with a top height up to
11–12 km. However, in some cases at the beginning of the period
the thickness of those layers reached several kilometers in Évora and
Madrid. The optical thicknesses associated to those layers were rather low
(between 0.013 and 0.020 in average over the whole period), with
peak values near 0.10 detected on 7 May. Secondly, the volcanic
aerosols were characterized in terms of extinction and backscatter
coefficients, lidar ratios, Ångström exponents and linear particle
depolarization ratio. Lidar ratios at different sites varied between 30 and
50 sr without a marked spectral dependency. Similar extinction-related
Ångström exponents varying between 0.6 and 0.8 were observed at
different sites. The temporal evolution of the backscatter-related
Ångström exponents points out a possible decrease of the volcanic
particle size as the plume moved from west to east. Particle depolarization
ratios on the order of 0.06–0.08 confirmed the coexistence of both ash
and non-ash particles. Additionally, profiles of mass concentration were
obtained with a method using the opposite depolarizing effects of ash
particles (strongly depolarizing), non-ash particles (very weakly
depolarizing), and sun-photometer observations. In Granada the ash mass
concentration was found to be approximately 1.5 times higher than that of
non-ash particles, and probably did not exceed the value of 200 μg m−3 during the whole event. |
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