Abstract

The three-dimensional structure and evolution ofan isolated and stationary microburst are simulated usinga time-dependent, high resolution Large-Eddy-Simulation(LES) model. The microburst is initiated by specifying asimplified cooling source at the top of the domain around2 km a.g.l. that leads to a strong downdraft. Surface windsof the order of 30ms-1 were obtained over a region of500m 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 consistentwith results obtained from numerical simulations of microburstsusing cloud-resolving models. The simulated flowreplicated some of the principal features of microbursts observedby Doppler radars: in particular, the horizontal spreadof strong surface winds and a ring vortex at the leadingedge of the cold outflow. In addition to the primary surfaceoutflow, the simulation also generated a secondary surge ofstrong winds that appears to represent a pulsation in the microburstevolution.These results highlight the capability of LES to reproducecomplex phenomena like microbursts, indicating the potentialusage of LES models to represent atmospheric phenomenaof time and space scales between the convective scaleand the microscale. These include short-lived convectivelygenerateddamaging winds.

Autore Pugliese

• Rizza Umberto

Tutti gli autori

• V. Anabor; U. Rizza; G.A. Degrazia; E. Lima Nascimento

Titolo volume/Rivista

Atmospheric chemistry and physics

Anno di pubblicazione

2011

ISSN

1680-7316

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

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Settori ERC

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Codici ASJC

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