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| Titel |
Volcanic aerosol layers observed with multi-wavelength Raman lidar over Europe since summer 2008 |
| VerfasserIn |
Ina Mattis, Patric Seifert, Detlef Müller, Matthias Tesche, Anja Hiebsch, Thomas Kanitz, Jörg Schmidt, Fanny Finger |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250040231
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| Zusammenfassung |
| Regular multiwavelength Raman lidar observations of the vertical aerosol distribution have
been performed at Leipzig (51.4-N, 12.4-E), Germany, since 1996 in the framework of the
European Aerosol Research Lidar Network (EARLINET). Our measurements in the past
12 years do not show any major event of volcanic aerosol pollution in the upper
troposphere–lower stratosphere (UTLS) region. The situation changed since summer
of 2008 due to a series of strong eruptions of volcanoes on the Aleutian Islands,
Kamchatka, Alaska, and on the Kuril Islands. We observed aerosol layers in the upper
troposphere above 5Â km height and lower stratosphere below 25Â km height. FLEXPART
transport simulations show that volcanic aerosol is advected from Alaska to central
Europe within about 7 days. The optical depths of the volcanic aerosol layers are
mostly between 0.004 and 0.025 at 532Â nm. The wavelength dependence of the
backscatter and extinction coefficients indicate Ångström exponents from 1.0–2.0. Lidar
ratios are found in the range from 30–80Â sr (355Â nm) and 30–50Â sr (532Â nm). The
estimation of the effective radius, surface–area, and mass concentrations of a volcanic
aerosol layer, observed well within the stratosphere end of August 2009, reveals
values of 0.1–0.2 μm, 5–10 μm2 cm-3, and 0.3–0.5 μg m-3, respectively. The
surface–area and mass concentrations are thus about a factor of 10–20 lower than the
respective values observed after the Mt. Pinatubo eruption in the years 1992 and 1993. |
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