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| Titel |
Observation of halogen oxides in volcanic plumes at Different Plume Ages |
| VerfasserIn |
Leif Vogel, Christoph Kern, Nicole Bobrowski, Christoph Hörmann, Roland v. Glasow, Ulrich Platt |
| 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 |
250043404
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| Zusammenfassung |
| Ground based remote sensing measurements in the near UV and VIS using Differential
Optical are now a standard tool to assess information of volcanic emissions. Next to the
detection of sulphuric dioxide (SO2), the technique also allows detection of halogen oxides
(e.g. BrO, ClO and OClO), which are secondary, chemical products of primarily
hydrogenated halides. These products have a great impact on atmospheric chemistry
due their high reactivity and their contribution to ozone destruction cycles. The
fastest reaction cycle involves Bromine and is analogous to the polar “Bromine
Explosion” and observed Ozone Depletion Events. By using chemical models, one
can relate these measurements to the primary constituents and gain insight into
volcanic processes as well as determine the impact of volcanic emissions on the
atmosphere.
To study ongoing chemistry in volcanic plumes, dilution and dispersion of the plume can
be compensated by taking the ratio of a chemically inert tracer species to reactive
compounds. SO2 can be used as an approximate tracer for common plume ages studied
(hours). Simultaneous measurements at several different distances from the crater and thus
different plume ages (2 to 60 minutes after emission) have been performed in extensive
campaigns in July 2008 and 2009 at Mt. Etna, Italy. Although models show a continuous
raise of BrO/SO2 ratio, our data fails to show the predicted increase in ratio as the plume
grows older. |
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