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| Titel |
Estimation of volcanic ash emission profiles using ceilometer measurements and transport models |
| VerfasserIn |
Ka Lok Chan, Alexander Geiß, Josef Gasteiger, Frank Wagner, Matthias Wiegner |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250124716
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| Publikation (Nr.) |
 EGU/EGU2016-4194.pdf |
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| Zusammenfassung |
| In recent years, the number of active remote sensing systems grows rapidly, since several
national weather services initiated ceilometer networks. These networks are excellent tools to
monitor the dispersion of volcanic ash clouds and to validate chemical transport
models. Moreover, it is expected that the can be used to refine model calculations to
better predict situations that might be dangerous for aviation. As a ceilometer can be
considered as a simple single-wavelength backscatter lidar, quantitative aerosol profile
information, i.e., the aerosol backscatter coefficient (βp) profile, can be derived provided
that the ceilometer is calibrated. Volcanic ash concentration profile can then be
estimated by using prior optical properties of volcanic ash. These profiles are then
used for the inverse calculation of the emission profile of the volcanic eruption,
thus, improving one of the most critical parameters of the numerical simulation.
In this study, the Lagrangian particle dispersion model FLEXPART (FLEXible
PARTicle dispersion model) is used to simulate the dispersion of volcanic ash. We
simulate the distribution of ash for a given time/height grid, in order to compute the
sensitivity functions for each measurements. As an example we use ceilometer
measurements of the German weather service to reconstruct the temporal and spatial
emission profile of Eyjafjallajökull eruption in April 2010. We have also examined the
sensitivity of the retrieved emission profiles to different measurement parameters, e.g.,
geolocation of the measurement sites, total number of measurement sites, temporal and
vertical resolution of the measurements, etc. The first results show that ceilometer
measurements in principle are feasible for the inversion of volcanic ash emission profiles. |
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