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| Titel |
How accurate are volcanic ash simulations of the 2010 Eyjafjallajökull eruption? |
| VerfasserIn |
Helen Dacre, Natalie Harvey, Peter Webley, Don Morton |
| 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 |
250127425
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| Publikation (Nr.) |
 EGU/EGU2016-7302.pdf |
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| Zusammenfassung |
| In the event of a volcanic eruption the decision to close airspace is based on forecast ash
maps, produced using volcanic ash transport and dispersion models. In this paper we
quantitatively evaluate the spatial skill of volcanic ash simulations using satellite
retrievals of ash from the Eyjafjallajökull eruption during the period from 7-16 May
2010. We find that at the start of this period, 7-10 May, the model (FLEXPART) has
excellent skill and can predict the spatial distribution of the satellite retrieved ash
to within 0.5∘× 0.5∘ lat/lon. However, on the 10 May there is a decrease in the
spatial accuracy of the model, to 2.5∘× 2.5∘ lat/lon, and between 11-12 May the
simulated ash location errors grow rapidly. On the 11 May ash is located close to a
bifurcation point in the atmosphere, resulting in a rapid divergence in the modeled and
satellite ash locations. In general, the model skill reduces as the residence time of ash
increases. However, the error growth is not always steady. Rapid increases in error
growth are linked to critical points in the ash trajectories. Ensemble modeling using
perturbed meteorological data would help to represent this uncertainty and assimilation
of satellite ash data would help to reduce uncertainty in volcanic ash forecasts. |
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