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| Titel |
Real-time in situ measurements of volcanic plume physico-chemical properties using Controlled METeorological balloons |
| VerfasserIn |
Adam Durant, Paul Voss, Matthew Watson, Tjarda Roberts, Helen Thomas, Fred Prata, Jeff Sutton, Tamsin Mather, Melanie Witt, Matthew Patrick |
| 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 |
250035893
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| Zusammenfassung |
| While the climatic effects of volcanogenic sulphate aerosol in the stratosphere are well
characterised, the nature and global impact of sustained tropospheric volcanic degassing is
less well understood. In situ measurement of volcanic emissions can be used to understand
plume processes (e.g., microphysics and chemistry), and used to validate and improve remote
sensing techniques. New developments in sensor and communication technologies have led to
the production of miniaturized lightweight unmanned atmospheric measurement platforms.
Controlled METeorological (CMET) balloons collect real-time observations of atmospheric
physico-chemical properties at altitudes of up to 5 km for hours or even days at a time.
Standard measurements include pressure (± 10 mb), aspirated temperature (± 0.3 C),
relative humidity (± 5 %) and location (GPS position ± 5 m horizontal, ± 50 m
vertical).
Balloon platform-based measurements of volcanic plume properties were made for the first
time using CMET balloons equipped with miniature electrochemical sensors during the
eruption of Halema’uma’u crater (Kilauea) in Hawai’i in 2008. In addition, multiple
measurement platforms were simultaneously deployed that included (1) ground-based remote
measurements (mini-DOAS and UV camera); (2) satellite-based sensors (MODIS and OMI);
and (3) in situ sampling at the emission source using ground-based electrochemical sensor
instrumentation.
During the 25 July 2008 flight, a single CMET balloon remained in the plume and collected
data for several hours. Ratios of [H2O] and [SO2] correlate in proximal regions of the plume,
though were found to anti-correlate further downwind. Correlation is explained through
co-emission of SO2 and H2O at source, as has been frequently previously observed e.g. by
FTIR. Anti-correlation of [H2O] and [SO2] ratios has not previously been reported and may
reflect dehydration of the aged plume through condensation of water vapour on volcanogenic
sulphate aerosol. The sulphate aerosol was likely a mixture produced from high
temperature processes in and near the vent and low temperature processes during transport
downwind. |
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