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| Titel |
Compositional variation in aging volcanic plumes - Analysis of gaseous SO2, CO2 and halogen species in volcanic emissions using an Unmanned Aerial Vehicle (UAV). |
| VerfasserIn |
Julian Rüdiger, Lukas Tirpitz, Nicole Bobrowski, Alexandra Gutmann, Marcello Liotta, Maarten de Moor, Thorsten Hoffmann |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250138004
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| Publikation (Nr.) |
 EGU/EGU2017-892.pdf |
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| Zusammenfassung |
| Volcanoes are a large source for several reactive atmospheric trace gases including sulfur and
halogen containing species. The detailed understanding of volcanic plume chemistry is
needed to draw information from gas measurements on subsurface processes. This knowledge
is essential for using gas measurements as a monitoring tool for volcanic activity. The
reactive bromine species bromine monoxide (BrO) is of particular interest, because BrO as
well as SO2 are readily measurable from safe distance by spectroscopic remote sensing
techniques. BrO is not directly emitted, but is formed in the plume by a multiphase reaction
mechanism. The abundance of BrO changes as a function of the distance from the vent as
well as the spatial position in the plume. The precursor substance for the formation
of BrO is HBr with Br2as an intermediate product. In this study we present the
application of a UAV as a carrier for a remote-controlled sampling system for halogen
species (Br2, HBr, BrCl, etc), based on the gas diffusion denuder technique, which
allows speciation and enrichment by selective organic reactions. For the analysis of
gaseous SO2 and CO2 an in-situ gas monitoring system was additionally mounted.
This setup was deployed into the gas plumes of Stromboli Volcano (Italy), Masaya
Volcano (Nicaragua) and Turrialba Volcano (Costa Rica) in 2016, to investigate
the halogen chemistry at distant locations in the plume further downwind to the
emission source, which are in most cases not accessible by other approaches. Flights
into the plume were conducted with ascents of up to 1000 m. From telemetrically
transmitted SO2 mixing ratios, areas of dense plume where localized to keep the
UAV stationary for up to 10 minutes of sampling time. Additionally, ground based
samples were taken at the crater rim (at Masaya and Turrialba) using alkaline traps,
denuder and gas sensors for comparison with airborne-collected data. Herein we will
present time and spatial resolved gas mixing ratio data for SO2, CO2 and halogen
species for crater rim sites and a downwind plume age of about 3 to 5 minutes. |
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