Detection of coherent oceanic structures via transfer operators
Detection of coherent oceanic structures via transfer operators
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DOI：
10.1103/physrevlett.98.224503
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发表时间：
2007-06-01
影响因子：
8.6
通讯作者：
Treguier, Anne Marie
中科院分区：
文献类型：
--
作者：
Froyland, Gary;Padberg, Kathrin;Treguier, Anne Marie
相干非色散结构在解释非自治动力学系统（如海洋流动）中的输运过程中起着至关重要的作用。这些结构很难从模型输出中提取，因为它们本质上是拉格朗日的，而不是由底层的欧拉速度场揭示的。在过去的几年中，启发式的概念，如有限时间李雅普诺夫指数已被用于试图检测海洋运输的障碍，从而确定区域的陷阱物质，如营养物质和浮游植物。在这封信中，我们追求一种新的，更直接的方法来发现相干区域的表面海洋使用高分辨率的模型速度数据。我们的方法基于数值构建一个转移算子，该算子控制颗粒在短时间内的表面传输。我们将我们的技术应用于南大洋的极地纬度。
Coherent nondispersive structures are known to play a crucial role in explaining transport in nonautonomous dynamical systems such as ocean flows. These structures are difficult to extract from model output as they are Lagrangian by nature and not revealed by the underlying Eulerian velocity fields. In the last few years heuristic concepts such as finite-time Lyapunov exponents have been used in an attempt to detect barriers to oceanic transport and thus identify regions that trap material such as nutrients and phytoplankton. In this Letter we pursue a novel, more direct approach to uncover coherent regions in the surface ocean using high-resolution model velocity data. Our method is based upon numerically constructing a transfer operator that controls the surface transport of particles over a short period. We apply our technique to the polar latitudes of the Southern Ocean.