The Surface Pathways of the South Atlantic: Revisiting the Cold and Warm Water Routes Using Observational Data
The Surface Pathways of the South Atlantic: Revisiting the Cold and Warm Water Routes Using Observational Data
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DOI：
10.1029/2019jc015267
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发表时间：
2019-10-23
影响因子：
3.6
通讯作者：
Lozier, M. S.
中科院分区：
文献类型：
--
作者：
Drouin, K. L.;Lozier, M. S.
在南大西洋（SA）的大西洋经向翻转环流上肢源沃茨的相对贡献在很大程度上仍然没有得到解决。我们有助于一个决议，通过使用观测数据，探索水质量的途径喂养到本格拉电流，被认为是一个主要组成部分的大西洋经向翻转环流上肢在SA。我们专注于途径从太平洋通过德雷克通道（传统上称为“冷”水路线）和印度洋通过阿古拉斯泄漏（传统上称为“暖”水路线）。我们采用了两个主要的观测数据集：（1）来自美国国家海洋和大气管理局全球漂流者计划的表面漂流者轨迹和（2）海洋表面流分析实时产品。根据我们的拉格朗日分析，大多数粒子起源于德雷克海峡仍然在南极绕极流，与一小部分达到北方肢体的SA副热带环流，和一些渗透的厄古拉斯电流区域。大部分粒子释放在阿古拉斯电流遵循阿古拉斯返回电流和再循环在其附近。只有一小部分泄漏到SA中。观察到的途径揭示了两个源沃茨在巴西-马尔维纳斯汇流，SA副热带环流，本格拉电流，和厄古拉斯电流区域之间的强烈相互作用。从后向轨迹的结果表明，从德雷克海峡到本格拉电流的沃茨有相当大的贡献，但在这种贡献的大小上，两个数据集之间存在分歧。
The relative contributions of the Atlantic Meridional Overturning Circulation upper limb source waters in the South Atlantic (SA) remain largely unresolved. We contribute to a resolution by using observational data to explore water mass pathways feeding into the Benguela Current, considered a major component of the Atlantic Meridional Overturning Circulation upper limb in the SA. We focus on the pathways from the Pacific Ocean via the Drake Passage (traditionally termed the "cold" water route) and the Indian Ocean via Agulhas Leakage (traditionally termed the "warm" water route). We employ two main observational data sets: (1) surface drifter trajectories from the National Oceanic and Atmospheric Administration's Global Drifter Program and (2) the Ocean Surface Current Analysis Real-time product. Based on our Lagrangian analysis, the majority of particles originating in the Drake Passage remain in the Antarctic Circumpolar Current, with a small portion reaching the northern limb of the SA subtropical gyre, and a few infiltrating the Agulhas Current region. The majority of particles released in the Agulhas Current follow the Agulhas Return Current and recirculate in its vicinity. Only a small portion leaks into the SA. Observed pathways reveal strong interactions between the two source waters in the Brazil-Malvinas Confluence, the SA subtropical gyre, the Benguela Current, and the Agulhas Current region. Results from backward trajectories suggest a sizable contribution of waters from the Drake Passage to the Benguela Current but show disagreement between the two datasets in the magnitude of this contribution.