The shelf break front to the east of the sub-Antarctic island of South Georgia
The shelf break front to the east of the sub-Antarctic island of South Georgia
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DOI：
10.1016/s0278-4343(98)00112-5
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发表时间：
1999-05-01
影响因子：
2.3
通讯作者：
Priddle, J
中科院分区：
文献类型：
--
作者：
Brandon, MA;Murphy, EJ;Priddle, J
南格鲁吉亚亚南极洲岛屿位于极锋以南的极地沃茨，受到威德尔斯科舍汇流的影响，其沃茨到达该岛的东南海岸。1996年1月，对该岛东部进行了详细的水文调查，结果表明，大陆架上的沃茨比大陆架外的海水既温暖又新鲜。这些差异并不局限于地表沃茨。固有的密度差异导致了一个陆棚断裂前缘，其位置被定义为26.96 kg m（-3）等密度线在上升到表面时穿过30 dbar的点。在货架上和货架外沃茨之间的货架断裂前的斜率被认为是近似地转。虽然陆架断裂前缘的位置与任何特定的海底深度无关，但其位置受到该区域海底地形的强烈影响。证据是在一个特定的区域上升流沿着前面。在营养和叶绿素a数据中也观察到了货架上和货架外沃茨之间的差异：这些数据意味着货架上的生产力更高。物理和化学数据都表明，大陆架上和大陆架外的沃茨在深度上是相通的。这项研究还表明，陆架水可以穿越陆架断裂锋，并留在附近的岛屿。(C)1999爱思唯尔科技有限公司。保留所有权利。
The sub-Antarctic island of South Georgia lies in polar waters to the south of the Polar Front and is influenced by the Weddell Scotia Confluence whose waters reach the island's south east coast. In January 1996 a detailed hydrographic survey to the east of the island showed that on-shelf waters were both warmer and fresher than those off-shelf. These differences were not confined to surface waters. The inherent density differences resulted in a shelf break front, the position of which was defined as the point where the 26.96 kg m(-3) isopycnal crossed 30 dbar as it rose towards the surface. The slope of the shelf break front between the on- and off-shelf waters was found to be approximately geostrophic. Although the position of the shelf break front was not linked to any particular bottom depth, its position was strongly influenced by the bottom topography in the region. Evidence is presented for upwelling in one specific region along the front. Differences between the on- and off-shelf waters are also observed in nutrient and chlorophyll a data: These data implied greater productivity on-shelf. Both physical and chemical data suggest that on- and off-shelf waters communicate at depth. This study also shows that shelf water can cross the shelf break front and remain in the vicinity of the island. (C) 1999 Elsevier Science Ltd. All rights reserved.