A Deep Eastern Boundary Current Carrying Indian Deep Water South of Australia
A Deep Eastern Boundary Current Carrying Indian Deep Water South of Australia
复制标题
一股深东边界洋流将印度深水带到澳大利亚南部
DOI：
10.1029/2018jc014569
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
M. Mazloff
中科院分区：
文献类型：
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作者：
V. Tamsitt;L. Talley;M. Mazloff
在南半球，海洋的深层沃茨主要通过边界流从低纬度输送到高纬度。除了西部深海边界流，沿南大西洋、印度洋和太平洋东部边界的路径沿着将深水向极地输送到南大洋，在那里这些沃茨上升到海面。这些深层东部边界流及其物理驱动因素的特征并不清楚，特别是那些携带来自印度和太平洋盆地的富含碳和营养物的深层沃茨的驱动因素。在这里，我们描述了向极深的东部边界电流，进行印度深水沿着澳大利亚南部边界的南大洋使用相结合的水文观测和拉格朗日实验在涡流允许的海洋状态估计。我们发现了强有力的证据，深边界电流携带低氧，富碳的签名印度深水延伸1,500和3,000米之间沿着澳大利亚大陆坡，从30 ° S到南极绕极流西南塔斯马尼亚。根据拉格朗日粒子估计，这条路径从30 ° S向南输送约5.8 ± 1.3 Sv到南极绕极流的北方边界。这条途径的体积运输是高度可变的，是密切相关的弗林德斯电流的覆盖向西的体积运输。大气和海洋之间的热量和碳交换对我们的气候有很大的影响。重要的是要了解海洋将热量和碳输送到海面的路线。在南半球，沃茨（低于1,000米深）沿着大西洋、印度洋和太平洋的边界向南流向南极洲。在印度洋和太平洋，东部边界带着古老的、富含碳的沃茨向南，直到它们到达南大洋的海面。然而，从东印度洋向南深处流动的许多方面还没有得到很好的了解。虽然这种流动在20世纪90年代的船舶观测中得到了确认，但观测很少，而且这种深层流动的重要性尚未得到充分认识。本研究的目标是通过重新审视船舶观测和跟踪海洋模型中的虚拟粒子来描述印度东部边界流。结果显示，来自印度洋的深水沿着澳大利亚南部海岸流动，直到到达南极绕极流。深流的强度是高度可变的，并与上覆弗林德斯电流的变化有关。
In the Southern Hemisphere, the ocean's deep waters are predominantly transported from low to high latitudes via boundary currents. In addition to the Deep Western Boundary Currents, pathways along the eastern boundaries of the southern Atlantic, Indian, and Pacific transport deep water poleward into the Southern Ocean where these waters upwell to the sea surface. These deep eastern boundary currents and their physical drivers are not well characterized, particularly those carrying carbon and nutrient-rich deep waters from the Indian and Pacific basins. Here we describe the poleward deep eastern boundary current that carries Indian Deep Water along the southern boundary of Australia to the Southern Ocean using a combination of hydrographic observations and Lagrangian experiments in an eddy-permitting ocean state estimate. We find strong evidence for a deep boundary current carrying the low-oxygen, carbon-rich signature of Indian Deep Water extending between 1,500 and 3,000 m along the Australian continental slope, from 30◦S to the Antarctic Circumpolar Current southwest of Tasmania. From the Lagrangian particles it is estimated that this pathway transports approximately 5.8 ± 1.3 Sv southward from 30◦S to the northern boundary of the Antarctic Circumpolar Current. The volume transport of this pathway is highly variable and is closely correlated with the overlying westward volume transport of the Flinders Current. Plain Language Summary Heat and carbon exchange between the atmosphere and the ocean has a big impact on our climate. It is important to understand the routes by which the ocean delivers heat and carbon to the sea surface. In the Southern Hemisphere, deep waters (below 1,000-m depth) flow southward toward Antarctica along the boundaries of the Atlantic, Indian, and Pacific Oceans. In the Indian and Pacific Oceans, the eastern boundaries carry old, carbon-rich waters south until they reach the sea surface in the Southern Ocean. However, many aspects of the deep southward flow from the eastern Indian Ocean are not well understood. Although this flow was identified in observations from ships in the 1990's, there are few observations and the importance of this deep flow has not been fully appreciated. The goal of this study is to describe the Indian deep eastern boundary current by revisiting observations from ships and tracking virtual particles in an ocean model. The results show that deep water from the Indian Ocean flows along the southern coast of Australia until it reaches the Antarctic Circumpolar Current. The strength of the deep flow is highly variable and is related to variations in the overlying Flinders Current.
DOI：
10.1029/2018jc014400
发表时间：
2019
期刊：
Journal of Geophysical Research: Oceans
影响因子：
--
作者：
Schulze Chretien, Lena M.;Speer, Kevin
通讯作者：
Speer, Kevin