摘要: |
通过对海洋中长生命反气旋涡在Gauss型孤立地形上演变的研究,发现地形对长生命反气旋涡的发展和传播有相当重要的影响。在无地形作用的情况下,仅有反气旋涡能够存在于向西的均匀基流中,这个涡是长生命的,并且在西移过程中有明显的向西倾斜。然而当其上游存在一个孤立地形时,可以发现这个涡有一个向东的倾斜,它的强度将增强且向西的移速会增加,其规迹象陀螺的运动。另一方面,当两个强度相同的反气旋涡同时存在时,这两个涡并不合并,且能持续很长的时间。当这两个涡的上游存在一个孤立地形时,这两个涡可以产生合并,并形成一个强度相当大的涡。 |
关键词: 海洋涡旋 反气旋涡 孤立地形 演变 合并 |
DOI:10.11693/hyhz200004003003 |
分类号: |
基金项目:青岛海洋大学青年教师基金资助项目 |
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THE EVOLUTION OF LONG-LIVED ANTICYCLONIC VORTICES OVER TOPOGRAPHY IN AN OCEAN AND THEIR MERGING |
LUO De-hai, LU Yan
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College of Marine and Environmental Sciences, Ocean University of Qingdao, Qingdao266003
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Abstract: |
In this paper, the evolution of long-lived anticyclonic vortices over a Gaussian-shape topography is investigated. It is found that the Gaussian-shape topography has an important influence on the evolution of the long-lived anticyclonic vortices. Under the condition that there is no topographic forcing, only anticyclonic vortices can exist in the uniform westward basic flow. These vortices are long-lived and have a westward tilt. However, if a Gaussian-shape topography exists in the upstream of an anticyclonic vortex, then the vortex will be strengthened and its westward speed increases. Its trajectory looks like the motion of a top. On the other hand, when two anticyclonic vortices having an identical amplitude exist in a uniform westward basic flow, the two vortices do not merge if the topography does not exist. However, once a Gaussian- shape topography exists in the upstream of the two vortices, they can merge and develop into a strong anticyclonic vertex. |
Key words: Oceanic vortices, Anticyclonic vortices, Solitary topography, Evolution, Merging |