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| Titel |
Large-Eddy Simulation of a microburst |
| VerfasserIn |
V. Anabor, U. Rizza, E. L. Nascimento, G. A. Degrazia |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 11, no. 17 ; Nr. 11, no. 17 (2011-09-09), S.9323-9331 |
| Datensatznummer |
250010065
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| Publikation (Nr.) |
 copernicus.org/acp-11-9323-2011.pdf |
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| Zusammenfassung |
The three-dimensional structure and evolution of an isolated and stationary
microburst are simulated using a time-dependent, high resolution
Large-Eddy-Simulation (LES) model. The microburst is initiated by specifying
a simplified cooling source at the top of the domain around 2 km a.g.l. that
leads to a strong downdraft. Surface winds of the order of 30 m s−1 were
obtained over a region of 500 m radius around the central point of the
impinging downdraft, with the simulated microburst lasting for a few
minutes. These characteristic length and time scales are consistent with
results obtained from numerical simulations of microbursts using
cloud-resolving models. The simulated flow replicated some of the principal
features of microbursts observed by Doppler radars: in particular, the
horizontal spread of strong surface winds and a ring vortex at the leading
edge of the cold outflow. In addition to the primary surface outflow, the
simulation also generated a secondary surge of strong winds that appears to
represent a pulsation in the microburst evolution.
These results highlight the capability of LES to reproduce complex phenomena
like microbursts, indicating the potential usage of LES models to represent
atmospheric phenomena of time and space scales between the convective scale
and the microscale. These include short-lived convectively-generated
damaging winds. |
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