海洋中地形强迫的孤立涡旋的演变及其相互作用
Evolution of solitary eddies over a Gaussian topographyand their interaction
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摘要: 建立了一个描述中尺度涡的新的非线性方程,然后利用变分原理研究了孤立涡旋的Liapunov稳定性,指出反气旋和气旋涡都是稳定的。数值计算结果发现在β效应的作用下这些涡旋都向西移动而不存在向南的移动,然而在反气旋涡的上游存在一个孤立地形(例如海山)的话,孤立地形会使反气旋涡向南移动,而且移动的轨迹取决于孤立地形的位置。当两个反气旋涡同时存在并发生相互作用时,上游孤立地形使这两个反气旋涡产生弱合并并出现弱分离。而且孤立地形的位置对这两个涡的移动和旋转有重要影响。
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关键词:
- 中尺度涡 /
- Liapunov稳定性 /
- 孤立地形 /
- 合并
Abstract: A new nonlinear equation describing mesoscale eddies in the oceanic flow is established. Using the variational principle, the Liapunov stability of the solitary eddies is discussed. It can be found that both cyclonic and anticyclonic solitary eddies are stable. Numerical computations show that the anticyclonic solitary eddies propagate westward due to the β effect. However, when a Gaussian topography (seamount) is located in upstream of an anticyclonic eddy, the solitary topography can make the anticyclonic eddy move southwards, and its path depends on the location of the Gaussian topography. Furthermore, when two anticyclonic eddies interact, the upstream solitary topography can snake them produce weak merging and weak separation. It is found that the localion of the solitary topography affecu the migration and rotation of these two eddies.-
Key words:
- Mesoscale eddy /
- Liapunov stability /
- solitary topography /
- merging
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