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| Titel |
First detection of Cl2 in the volcanic plume from Mt. Etna |
| VerfasserIn |
D. Schäuble, C. Voigt, P. Jessberger, T. Jurkat, S. Kaufmann |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250070239
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| Zusammenfassung |
| Degassing volcanoes are large local sources of atmospheric halogens including
chlorine species. Chlorine emissions from degassing volcanoes may affect methane
oxidation in the troposphere, while their injection into the stratosphere may cause ozone
destruction.
Here we present new mass spectrometric in-situ measurements in the outgassing
plume from the Sicilian volcano Mt. Etna. On 29 and 30 September 2011 during
the CONCERT2011 campaign, the trace gas and particle composition of the Etna
plume was probed with instruments onboard the DLR research aircraft Falcon.
Elevated concentrations of chlorine and bromine species, as well as gaseous SO2 and
HNO3 were detected with two Atmospheric chemical Ionization Mass Spectrometers
(AIMS) onboard the Falcon. Here we focus on the detection of molecular chlorine
within the young volcanic plume. Up to several nmol/mol Cl2 and about an order of
magnitude higher HCl mixing ratios were measured. The ratio of these two chlorine
compounds and its evolution over 12 hours plume age are investigated. We speculate
that the molecular chlorine had been injected directly by the Etna or had formed
heterogeneously on sulphate aerosol and on coated volcanic ash particles within the
plume.
To our knowledge, these are the first atmospheric observations of Cl2 within a volcanic
plume. The detection of molecular chlorine could promote new laboratory measurements of
the reaction rates of chlorine species on coated volcanic ash particles. Further our data
provide an input to microphysical and photochemical models. These may help to answer
questions related to methane oxidation in regions, which are affected by volcanic
emissions. |
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