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| Titel |
The vertical distribution of volcanic SO2 plumes measured by IASI |
| VerfasserIn |
Elisa Carboni, Roy Grainger, Tamsin A. Mather, David M. Pyle, Gareth Thomas, Richard Siddans, Andrew Smith, Anu Dudhia, MariLiza Koukouli, Dimitris Balis |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250111263
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| Publikation (Nr.) |
 EGU/EGU2015-11365.pdf |
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| Zusammenfassung |
| Sulphur dioxide (SO2) is an important atmospheric constituent that plays a crucial role in
many atmospheric processes. For example the current hiatus in global warming has been
suggested to be caused by low level (< 15 km) volcanic activity (Ridley et al., 2014).
Volcanic eruptions are a significant source of atmospheric SO2 and its effects and lifetime
depend on the SO2 injection altitude. In the troposphere SO2 injection leads to the
acidification of rainfall while in the stratosphere it oxidises to form a stratospheric H2SO4
haze that can affect climate for several years. The Infrared Atmospheric Sounding Instrument
(IASI) on the Metop satellite can be used to study volcanic emission of SO2 using
high-spectral resolution measurements from 1000 to 1200 cm-1 and from 1300 to 1410
cm-1 (the 7.3 and 8.7 μm SO2 bands). The scheme described in Carboni et al. (2012) has
been applied to measure volcanic SO2 amount and altitude for 14 explosive eruptions from
2008 to 2012. The work includes a comparison with independent measurements: (i) the
SO2 column amounts from the 2010 Eyjafjallajökull plumes have been compared
with Brewer ground measurements over Europe; (ii) the SO2 plumes heights have
been compared with CALIPSO backscatter profile. The results of the comparisons
show that IASI SO2 measurements are not affected by underling cloud and are
consistent (within the retrieved errors) with the other measurements considered. The
series of analysed eruptions (2008 to 2012) show that the biggest contributor of
volcanic SO2 was Nabro, followed by Kasatochi and Grímsvötn. Our observations
also show a tendency of the volcanic SO2 to be injected to the level of tropopause
during many explosive eruptions. For the eruptions observed, this tendency was
independent of the maximum amount of SO2 erupted (e.g., 0.2ÂTg for Dalafilla compared
with 1.6ÂTg for Nabro) and of the volcanic explosive index (between 3 and 5). |
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