Three-dimensional properties of mesoscale eddies in the South China Sea based on eddy-resolving model output
Three-dimensional properties of mesoscale eddies in the South China Sea based on eddy-resolving model output
复制标题
基于涡分辨模型输出的南海中尺度涡三维特性
DOI：
10.1016/j.dsr.2015.01.007
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发表时间：
2015-05-01
影响因子：
2.4
通讯作者：
Guan, Yuping
中科院分区：
文献类型：
--
作者：
Lin, Xiayan;Dong, Changming;Guan, Yuping
近十年来，对南海中尺度海洋涡旋的研究较为广泛，但大多集中在海面涡旋上，除了个别涡旋外，涡旋的三维特征尚不清楚。我们将三维涡旋探测方案应用于9年（2000-2008）涡旋解析数值解，以获取南海的三维涡旋数据集。用季节和季节内尺度的观测资料验证了模型解。模型得到的海面涡旋的统计特征，如涡旋数、寿命和半径，与卫星测高数据具有可比性。通过对三维涡旋数据集的统计分析，揭示了涡旋物理特征的垂直剖面。例如，在约350 m以上深度，气旋涡旋（CEs）比反气旋涡旋（ae）产生的多，而在350 m以下则呈现相反的趋势。在不同的垂直水平上，ce和ae的寿命在统计学上是相等的，没有显著变化。南海中部的涡旋大小最大，且随水深的增加而减小。旋涡相对涡度幅值随深度的增加而减小。涡旋有三种不同的类型：碗状涡旋在表面最大，透镜状涡旋在中间最大，锥形涡旋在底部最大。大多数的涡流是碗状的。三种类型的涡旋对温度和盐度剖面的影响不同。讨论了南海涡旋的形成机制，并将其分为三种类型：地面风旋度输入、洋流与海底地形的相互作用和黑潮侵入。(C) 2015 Elsevier Ltd.版权所有。
Last decade has witnessed extensive studies on mesoscale oceanic eddies in the Southern China Sea (SCS), however most of these studies are focused on the surface eddies, and three-dimensional features of eddies are not well known except some individual eddies. We apply a three-dimensional eddy detection scheme to a 9-year (2000-2008) eddy-resolving numerical solution to acquire three-dimensional eddy data set in the SCS. The model solution is validated with observational data in terms of both seasonal and intra-seasonal scales. The statistical characteristics of eddies at the sea surface, such as eddy number, lifetime and radius, from the model are comparable with those derived from the satellite altimetry data. The vertical profiles of the physical features of eddies are exposed from the statistical analysis of the three-dimensional eddy data set. For examples, more cyclonic eddies (CEs) are generated than anticyclonic eddies (AEs) in the depth above about 350 m and an opposite trend is presented below 350 m. The lifetimes of CEs and AEs are statistically equal and no significant variation at different vertical levels. Eddies in the central SCS have the largest size than in other areas and their sizes decrease with the increase in water depth. The relative vorticity amplitude of eddies decreases with the increase in the depth. There are three different types of eddies: bowl-shaped with the largest size at the surface, lens-shaped with the largest size in the middle and cone-shaped with the largest size at the bottom. Most of eddies are bowl-shaped eddies. The three types of eddies have different effects on the temperature and salinity profiles. Eddy genesis mechanisms are discussed and categorized into three types in the SCS: surface wind curl input, current interaction with the bottom topography and Kuroshio intrusion. (C) 2015 Elsevier Ltd. All rights reserved.