Influence of a Strong Bottom Slope on the Evolution of a Surface-Intensified Vortex
Influence of a Strong Bottom Slope on the Evolution of a Surface-Intensified Vortex
复制标题
强底部坡度对表面强化涡演化的影响
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
Y. Morel
中科院分区：
文献类型：
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作者：
V. Thierry;Y. Morel
摘要作者在一个两层准地转模式中研究了陡底地形对涡旋传播的影响。涡在上层加强，并考虑了行星β效应。作者发现，陡峭的地形可以散射上层涡旋位移产生的扰动，并保持低层运动弱。因此，它表明，当涡半径小于临界值，涡的行为，如果下层是在休息（或无限深，在一个简化的重力模型）。如果半径增加，同时保持最大涡度的漩涡，地形Rossby波的散射过程中产生的有一个更强的签名在上层，和漩涡的演变开始改变相比，减少重力的情况下。然而，数值试验表明，无论是陡峭的地形和减重力轨迹仍然接近一个大的半径，之后，上方的涡旋。
Abstract The authors investigate the influence of steep bottom topography on the propagation of a vortex in a two-layer quasigeostrophic model. The vortex is intensified in the upper layer and the planetary beta effect is taken into account. The authors find that steep topography can scatter disturbances created by the upper-layer vortex displacement and maintain the lower-layer motion weak. It is thus shown that, when the vortex radius is smaller than a critical value, the vortex behaves as if the lower layer was at rest (or infinitely deep as in a reduced gravity model). If the radius is increased while holding the maximum vorticity of the vortex, the topographic Rossby waves—generated during the scattering process—have a stronger signature in the upper layer, and the vortex evolution begins to change in comparison with the reduced-gravity case. However, numerical experiments show that both the steep topography and reduced-gravity trajectories remain close up to a large radius, after which a vortex abov...