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| Titel |
Coincident observations of SO2 and BrO from volcanic eruptions by the GOME-2 instrument |
| VerfasserIn |
Christoph Hörmann, Holger Sihler, Nicole Bobrowski, Christoph Kern, Marloes Penning de Vries, Leif Vogel, Ulrich Platt, Thomas Wagner |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250050447
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| Zusammenfassung |
| Bromine monoxide (BrO) plays a key role as a catalyst in the depletion of both, tropospheric
and stratospheric ozone (O3), e.g. during springtime in polar regions. In addition to sources
like salt lakes or the surface of sea ice in polar regions, volcanic emissions are a further
natural source of BrO. Injections of volcanic BrO into the troposphere by degassing
volcanoes, or into the stratosphere during a major eruption, are therefore very likely to have
an important impact on atmospheric chemistry. Since the first observation of BrO in the
volcanic plume of Soufrière Hills in 2002 by ground-based Multi-Axis Differential Optical
Absorption Spectroscopy (MAX-DOAS) measurements, similar observations have been
made at several volcanoes worldwide. After the eruption of the Kasatochi volcano in 2008,
large amounts of volcanic BrO were also detected for the first time by a satellite instrument
(GOME-2). The capability of GOME-2 to monitor such events allows the examination of
entire volcanic plumes on a much larger scale than is possible using ground-based
measurements.
We present results from a study of all volcanic eruptions that were monitored by the
GOME-2 instrument during the period between January 2007 and June 2010, and in which
both sulfur dioxide (SO2) and BrO were observed in the vicinity of the volcanic plume. The
resulting slant column densities (SCDs) for SO2 and BrO are investigated for a
possible correlation and the BrO/SO2 ratios are discussed. Unlike what has been
reported from ground-based measurements alone, a close correlation between SO2 and
BrO appears to occur only for some of the observed eruptions, or only for certain
parts of the examined volcanic plumes. Ideas are presented which try to explain the
occurrence of different spatial SO2 and BrO distributions in aged volcanic plumes. |
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