Export of Weddell Sea Deep and Bottom Water
Export of Weddell Sea Deep and Bottom Water
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DOI：
10.1029/2000jc000281
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发表时间：
2001-05-15
影响因子：
3.6
通讯作者：
Huber, B
中科院分区：
文献类型：
--
作者：
Gordon, AL;Visbeck, M;Huber, B
1997年8月在威德尔海西北部获得的一套广泛的电导率-温度-深度（CTD）/降低声学多普勒海流剖面仪（LADCP）数据表征了从威德尔海流出的密集水和溢出到斯科舍海。沿着威德尔环流的外缘，有一条相对低盐度、高含氧的威德尔海深水（定义为0度到-0.7摄氏度之间的水），构成了一种比在环流更远的地方发现的更通风的水团。其增强的通风是由于在南极半岛威德尔海陆架的北方极端附近发现的相对低盐度的陆架水的注入，陆架水太浮力而不能下降到深海海底。威德尔海深层水的通风性较好，沿着南奥克尼高原的东侧向北流动，进入斯科舍海，而不是继续沿着威德尔海北方的一条向东路径流动。威德尔海底水也表现出两种形式：一种是低盐度、含氧较好的成分，局限于威德尔环流的外缘;另一种是含盐量较高、含氧较少的成分，观察到更远的环流。更咸的威德尔海底水来自威德尔海西南部，那里有大量的高盐度陆架水。威德尔海底水的盐度较低，就像威德尔海深水的通风性较好一样，来自南极半岛更北沿着的低盐度陆架水。根据LADCP的一次调查，横跨西经44度的威德尔海深水和底层水团的输运量分别为25 x 10（6）和5 x 10（6）m（3）s（-1）。低盐度、通风较好的威德尔海深水和底层水沿着威德尔环流外缘流动，其位置和深度范围将导致威德尔盆地的地形范围溢出，而含盐量较高的形式可能被迫在威德尔环流内再循环。
An extensive set of conductivity-temperature-depth (CTD)/lowered acoustic Doppler current profiler (LADCP) data obtained within the northwestern Weddell Sea in August 1997 characterizes the dense water outflow from the Weddell Sea and overflow into the Scotia Sea. Along the outer rim of the Weddell Gyre, there is a stream of relatively low salinity, high oxygen Weddell Sea Deep Water (defined as water between 0 degrees and -0.7 degreesC), constituting a more ventilated form of this water mass than that found farther within the gyre. Its enhanced ventilation is due to injection of relatively low salinity shelf water found near the northern extreme of Antarctic Peninsula's Weddell Sea shelf, shelf water too buoyant to descend to the deep-sea floor. The more ventilated form of Weddell Sea Deep Water flows northward along the eastern side of the South Orkney Plateau, passing into the Scotia Sea rather than continuing along an eastward path in the northern Weddell Sea. Weddell Sea Bottom Water also exhibits two forms: a low-salinity, better oxygenated component confined to the outer rim of the Weddell Gyre, and a more saline, less oxygenated component observed farther into the gyre. The more saline Weddell Sea Bottom Water is derived from the southwestern Weddell Sea, where high-salinity shelf water is abundant. The less saline Weddell Sea Bottom Water, like the more ventilated Weddell Sea Deep Water, is derived from lower-salinity shelf water at a point farther north along the Antarctic Peninsula. Transports of Weddell Sea Deep and Bottom Water masses crossing 44 degreesW estimated from one LADCP survey are 25 x 10(6) and 5 x 10(6) m(3) s(-1), respectively. The low-salinity, better ventilated forms of Weddell Sea Deep and Bottom Water flowing along the outer rim of the Weddell Gyre have the position and depth range that would lead to overflow of the topographic confines of the Weddell Basin, whereas the more saline forms may be forced to recirculate within the Weddell Gyre.