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Titel |
Quantification of the depletion of ozone in the plume of Mount Etna |
VerfasserIn |
L. Surl, D. Donohoue, A. Aiuppa, N. Bobrowski, R. von Glasow |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
1680-7316
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Digitales Dokument |
URL |
Erschienen |
In: Atmospheric Chemistry and Physics ; 15, no. 5 ; Nr. 15, no. 5 (2015-03-09), S.2613-2628 |
Datensatznummer |
250119505
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Publikation (Nr.) |
copernicus.org/acp-15-2613-2015.pdf |
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Zusammenfassung |
Volcanoes are an important source of inorganic halogen species into the
atmosphere. Chemical processing of these species generates oxidised, highly
reactive, halogen species which catalyse considerable O3 destruction
within volcanic plumes. A campaign of ground-based in situ O3,
SO2 and meteorology measurements was undertaken at the summit of
Mount Etna volcano in July/August 2012. At the same time, spectroscopic
measurements were made of BrO and SO2 columns in the plume
downwind.
Depletions of ozone were seen at all in-plume measurement locations, with average O3
depletions ranging from 11–35 nmol mol−1 (15–45%). Atmospheric processing
times of the plume were estimated to be between 1 and 4 min. A 1-D numerical model of early
plume evolution was also used. It was found that in the early plume O3 was destroyed at an
approximately constant rate relative to an inert plume tracer. This is ascribed to reactive halogen
chemistry, and the data suggests the majority of the reactive halogen that destroys O3 in
the early plume is generated within the crater, including a substantial proportion generated in a
high-temperature "effective source region" immediately after emission. The model could approximately
reproduce the main measured features of the ozone chemistry. Model results show a strong dependence of
the near-vent bromine chemistry on the presence or absence of volcanic NOx emissions
and suggest that near-vent ozone measurements can be used as a qualitative indicator of NOx emission. |
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