Ocean circulation within the North Water Polynya of Baffin Bay
Ocean circulation within the North Water Polynya of Baffin Bay
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DOI：
10.1080/07055900.2001.9649683
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发表时间：
2001-09-01
期刊：
影响因子：
1.2
通讯作者：
Ingram, G
中科院分区：
文献类型：
--
作者：
Melling, H;Gratton, Y;Ingram, G
北水冰间湖是巴芬湾北方末端的一个周期性冰间湖。作为国际北方水项目的一部分，1997年至1998年期间，在这个冰间湖内停泊了记录流速的仪表，以研究其存在的物理原因。这些数据表明，北水波林亚主要是由来自北冰洋的强大的冷水和冰向南流动。虽然西格陵兰海流从东南方向向冰间湖引导了一股温和的温暖水流，但这股水流在冰间湖以南通过再循环进入北极外流并与之等密度混合而失去了大部分热量。如果一个冰塞阻止了来自北方的冰的流入，那么在冰塞下方继续向南漂移的冰足以在没有海洋加热的情况下形成一个大的冰穴。然而，格陵兰海岸附近的上升流可以将相对温暖的水带到湍流表层的底部，在那里它通过由冰中生长的盐水驱动的对流被夹带。由此产生的感热通量提供了大约三分之一的地表热量损失，并减缓了冰的生长。由于感热通量依赖于冻结，它在春季随着冰的生长减缓而减少，并且本身不能在年初产生无冰的沃茨。
The North Water Polynya is a recurrent polynya at the northern end of Baffin Bay. As part of the International North Water Project, recording current meters were moored within this polynya during 1997-98 to study the physical reasons for its existence. The data demonstrate that the North Water Polynya is dominated by a strong southward flow of cold water and ice from the Arctic Ocean. Although the West Greenland Current directs a modest flow of warmer water towards the polynya from the south-east, this flow loses much of its heat south of the polynya through re-circulation into and isopycnal mixing with the Arctic outflow. If an ice jam stops the inflow of ice from the north, the continued drift of ice southward below the blockage is sufficient to create a large polynya without oceanic heating. However, upwelling near the Greenland coast can bring relatively warm water to the base of the turbulent surface layer where it is entrained via convection driven by brine growing from ice. The resulting flux of sensible heat supplies about one-third of the heat loss at the surface and slows ice growth. Because the sensible heat flux is dependent upon freezing, it decreases as ice growth slows in spring and cannot, itself, generate ice-free waters early in the year.