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contributor authorGawarkiewicz, Glen
contributor authorChapman, David C.
date accessioned2017-06-09T14:50:04Z
date available2017-06-09T14:50:04Z
date copyright1991/08/01
date issued1991
identifier issn0022-3670
identifier otherams-27805.pdf
identifier urihttp://onlinelibrary.yabesh.ir/handle/yetl/4164851
description abstractA depth-averaged model with no density variations was used by Chapman to describe the formation of a passive tracer front at a shelfbreak. The relevance of this frontogenesis mechanism to cases that allow vertical variations is examined by considering the three-dimensional structure of a passive tracer front with explicit finite vertical mixing and bottom boundary layer dynamics. A three-dimensional primitive-equation numerical model is configured in a channel with a continental shelf, slope, and abyssal plain running the length of the channel. A vertically and horizontally uniform inflow is imposed over the shelf, with a large horizontal velocity shear near the shelfbreak. In the primitive-equation model, the offshore flow is concentrated in the bottom boundary layer while the alongshelf flow distribution is similar to the depth-averaged case; the presence of the bottom topography maintains a strong horizontal shear near the shelfbreak above the bottom boundary layer. This velocity shear causes a smooth passive tracer distribution imposed at the inflow boundary to develop strong cross-shelf gradients near the shelfbreak (i.e., a passive tracer front) within a rather short downstream distance, as in the depth-averaged model. Neutrally buoyant Lagrangian particles initialized above the bottom boundary layer are rapidly advected along the shelf with little cross-shelf motion. However, particles initialized within the bottom boundary layer move quickly offshore toward the shelfbreak and beyond while being advected alongshelf relatively slowly. The shelfbreak does not act as a barrier to the offshore transport of neutrally buoyant particles despite the presence of the passive tracer front. This results in a continuous net offshore transport from the shelf to the deep ocean due to the effects of bottom friction.
publisherAmerican Meteorological Society
titleFormation and Maintenance of Shelfbreak Fronts in an Unstratified Flow
typeJournal Paper
journal volume21
journal issue8
journal titleJournal of Physical Oceanography
identifier doi10.1175/1520-0485(1991)021<1225:FAMOSF>2.0.CO;2
journal fristpage1225
journal lastpage1239
treeJournal of Physical Oceanography:;1991:;Volume( 021 ):;issue: 008
contenttypeFulltext


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