Tide-topography interactions in a stratified shelf sea II. Bottom trapped internal tides and baroclinic residual currents
作者:
L.R. M. Maas,
J.T. F. Zimmerman,
期刊:
Geophysical & Astrophysical Fluid Dynamics
(Taylor Available online 1989)
卷期:
Volume 45,
issue 1-2
页码: 37-69
ISSN:0309-1929
年代: 1989
DOI:10.1080/03091928908208892
出版商: Taylor & Francis Group
关键词: Tide-topography interaction;bottom intensification;internal tides;baroclinic residual current;stratified shelf sea;quasi-nonlinear advection;geostrophic adjustment;vortex stretching
数据来源: Taylor
摘要:
The generation of topographically bounded internal tides and baroclinic residual currents is discussed for a linearly stratified fluid in the limit of small-amplitude topography and weak damping. It is shown that quasi-nonlinear advection by the barotropic tide generates a residual and higher harmonics, besides the ever present fundamental driving frequency in the internal motions. At all frequencies the along-isobath currents and the cross-isobath circulation arebottom intensified, the intensification being a function of the internal Rossby deformation radius. For a step topography the weak cross-isobath residual circulation has a characteristic three-cell structure with a down-slope bottom current at the position of the steepest slope, which is also the center of the along-isobath residual jet. In contrast to barotropic currents in the quasi-nonlinear regime, the baroclinic currents are exponentially bounded to the topography, rather than extending over a finite interval, in which thee-folding distance is the internal deformation radius.
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