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| Titel |
Simulations and parameterisation of shallow volcanic plumes of Piton de la Fournaise, Réunion Island, using Méso-NH version 4-9-3 |
| VerfasserIn |
S. G. Sivia, F. Gheusi, C. Mari, A. Di Muro |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1991-959X
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| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 8, no. 5 ; Nr. 8, no. 5 (2015-05-13), S.1427-1443 |
| Datensatznummer |
250116342
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| Publikation (Nr.) |
 copernicus.org/gmd-8-1427-2015.pdf |
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| Zusammenfassung |
| In mesoscale models (resolution ~ 1 km) used for regional dispersion of pollution plumes the
volcanic heat sources and emissions of gases and aerosols, as well as the induced atmospheric
convective motions, are all sub-grid-scale processes (mostly true for weak effusive eruptions)
which need to be parameterised. We propose a modified formulation of the EDMF scheme
(eddy diffusivity/mass flux) proposed by Pergaud et al. (2009) which is based on a single
sub-grid updraft model. It is used to represent volcano induced updrafts tested for a case study
of the January 2010 summit eruption of Piton de la Fournaise (PdF) volcano. The validation of this
modified formulation using a reference large eddy simulation (LES) focuses on the ability of the
model to transport tracer concentrations up to 1–2 km above the ground in the lower troposphere
as is the case of majority of PdF eruptions. The modelled volcanic plume agrees reasonably with
the profiles of SO2 (sulfur dioxide) tracer concentrations and specific humidity found from the
reference LES. Sensitivity tests performed for the modified formulation of the EDMF scheme
emphasise the sensitivity of the parameterisation to ambient fresh air entrainment at the plume
base. |
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