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contributor authorMitchell, Kenneth E.
contributor authorHovermale, John B.
date accessioned2017-06-09T16:01:37Z
date available2017-06-09T16:01:37Z
date copyright1977/05/01
date issued1977
identifier issn0027-0644
identifier otherams-59120.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4199643
description abstractThe structure of the thunderstorm gust front is investigated by a nonhydrostatic, two-dimensional (xz/) numerical model. In the model, which is dry, the production of negatively buoyant air by evaporation is parameterized via an externally imposed, local-cooling function. This parameterization sustains a steady cold downdraft, which drives the surface outflow and associated gust front. It is shown that two dominant factors influencing gust front structure in the vertical plane are the solenoidal field coincident with the front and surface friction, modeled by means of a simple bulk aerodynamic drag formulation. The circulation theorem is invoked to illustrate how solenoidal accelerations oppose the deceleration by surface friction. After the onset of a downdraft in the model, these opposing tendencies soon reach a balance. Thus, following a brief transient stage, the model gust front exhibits a persistent configuration as it propagates rapidly forward. The essential features of this configuration are examined and compared with both tower observations of gust fronts and laboratory models of gravity currents.
publisherAmerican Meteorological Society
titleA Numerical Investigation of the Severe Thunderstorm Gust Front
typeJournal Paper
journal volume105
journal issue5
journal titleMonthly Weather Review
identifier doi10.1175/1520-0493(1977)105<0657:ANIOTS>2.0.CO;2
journal fristpage657
journal lastpage675
treeMonthly Weather Review:;1977:;volume( 105 ):;issue: 005
contenttypeFulltext


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