Global observations of submesoscale coherent vortices in the ocean
Global observations of submesoscale coherent vortices in the ocean
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DOI：
10.1016/j.pocean.2020.102452
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发表时间：
2020-11
影响因子：
4.1
通讯作者：
D. McCoy;D. Bianchi;A. Stewart
中科院分区：
文献类型：
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作者：
D. McCoy;D. Bianchi;A. Stewart
地下强化的反气旋在海洋中无处不在，但它们对热、盐和化学示踪剂的大规模输送的影响却知之甚少。这些亚中尺度相干涡旋（scv）可以捕获和平流数千公里外的水形成区域，提供低分辨率地球系统模型无法解决的运输途径。然而，由于缺乏系统的观测，对这些涡旋对大尺度环流的重要性的认识受到阻碍。在这里，我们利用Argo浮标的全球网络来识别这些漩涡的出现，这些漩涡表现为具有高斯形状垂直结构的弱分层异常水团。我们开发了一种通用算法来检测已从其源区域传播的地下漩涡，并将其应用于Argo浮子剖面数据库，在20多年的观测中产生了大约4000次检测。我们进一步将检测分组到区域人群中，以确定产生的热点和形成机制。区域SCV统计分析揭示了东部边界上升流系统、边缘海溢流和主要开阔海锋的模态水形成区是SCV产生的重要地点。由于岩心中包含的热盐异常，在高SCV密度地区，SCV可能会对水团的水文特性留下显著的印记。
Subsurface-intensified anticyclones are ubiquitous in the ocean, yet their impact on the large-scale transport of heat, salt and chemical tracers is poorly understood. These submesoscale coherent vortices (SCVs) can trap and advect waters thousands of kilometers away from the formation region, providing a transport pathway that is unresolved by low-resolution Earth System Models. However, knowledge of the importance of these eddies for the large scale circulation is hindered by the lack of systematic observations. Here, we take advantage of the global network of Argo floats to identify occurrences of these eddies, which appear as weakly stratified anomalous water masses with Gaussian-shaped vertical structures. We develop a general algorithm to detect subsurface eddies that have propagated away from their source region, and apply it to the database of Argo float profiles, resulting in roughly 4000 detections from more than 20 years of observations. We further group detections into regional populations to identify hot-spots of generation and mechanisms of formation. Analysis of regional SCV statistics reveals important sites of SCV generation in Eastern Boundary Upwelling Systems, marginal sea overflows, and mode water formation regions along major open-ocean fronts. Because of the heat and salt anomaly contained within their cores, SCV could leave a significant imprint on the hydrographic properties of water masses in regions of high SCV density.