Strong export of Antarctic Bottom Water east of the Kerguelen plateau
Strong export of Antarctic Bottom Water east of the Kerguelen plateau
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DOI：
10.1038/ngeo842
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发表时间：
2010-05
影响因子：
18.3
通讯作者：
Y. Fukamachi;S. Rintoul;J. Church;S. Aoki;S. Sokolov;M. Rosenberg;M. Wakatsuchi
中科院分区：
文献类型：
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作者：
Y. Fukamachi;S. Rintoul;J. Church;S. Aoki;S. Sokolov;M. Rosenberg;M. Wakatsuchi
南极底层水从南大洋进入全球海洋的主要途径是南极半岛和科尔盖伦高原以东的西部深水边界流。以前的船基观测记录了与Kerguelen地区西部深边界流有关的不同的水性质和速度，但平均水流迄今尚不受限制。在这里，我们报告了由八个海流计系泊设备组成的相干阵列的测量结果，这些数据显示，一股狭窄而强烈的赤道水流穿过科尔盖伦高原以东的水柱。两年来的平均速度超过20 cm S−1在大约3,500 m的深度，这是在类似深度观察到的最强的平均西部边界流。我们估计，温度低于0∘C的水的赤道向输送平均为12.3±1.2×10~6m~3s−_1，部分由向极地气流补偿。我们还估计，低于0.2∘C的净赤道向水流约为8×106m3s−1，大大高于从韦德尔海向大西洋输送密集水到福克兰高原以北的边界流所报告的1.9x106m3s−1。我们认为，科尔盖伦深西部边界流是全球大洋深部翻转环流的重要通道。
The primary paths for the transport of Antarctic Bottom Water from the Southern Ocean into the global ocean are the deep western boundary currents east of the Antarctic Peninsula and the Kerguelen plateau. Previous ship-based observations documented distinct water properties and velocities associated with a deep western boundary current in the Kerguelen region,,,,,, but the mean flow is as yet unconstrained. Here we report measurements from a coherent array of eight current-meter moorings that reveal a narrow and intense equatorward flow extending throughout the water column just east of the Kerguelen plateau. Velocities averaged over two years exceed 20 cm s−1at depths of about 3,500 m, the strongest mean deep western boundary current flow yet observed at similar depths. We estimate the mean equatorward transport of water colder than 0∘C at 12.3±1.2×106m3s−1, partially compensated by poleward flow. We also estimate the net equatorward flow of water colder than 0.2∘C at about 8×106m3s−1, substantially higher than the 1.9×106m3s−1reported from the boundary current that carries dense water from the Weddell Sea into the Atlantic Ocean north of the Falkland plateau. We conclude that the Kerguelen deep western boundary current is a significant pathway of the global ocean’s deep overturning circulation.