Transformation and Fate of Overflows in the Northern North Atlantic
Transformation and Fate of Overflows in the Northern North Atlantic
复制标题
北大西洋北部溢流的转变和命运
DOI：
10.1007/978-1-4020-6774-7_22
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发表时间：
2008
影响因子：
3.4
通讯作者：
B. Dickson
中科院分区：
文献类型：
--
作者：
I. Yashayaev;B. Dickson
现代海洋学仪器记录中最大的全深度变化发生在过去40年中西北大西洋的拉布拉多盆地。那里异常条件的极端幅度及其声称的对温盐环流和气候的影响的重要性（例如Bryden等人，2005年）证明了确定整个副极地大西洋水柱变化起源的尝试。在拉布拉多盆地的深度大于开阔洋深对流的极限（2,300米左右），变化必然是由两个主要的密集水溢出，通过丹麦海峡和法罗群岛设得兰海峡跨越格陵兰-苏格兰海脊进口到盆地。形成这些溢流的每个组成水团（例如，见Rudels等人，2002年）都将在其源区带有随时间变化的气候强迫的印记，并在其流经的路线上带有随时间变化的气候强迫的印记，其性质也将受到从其溢流道到拉布拉多盆地的水平和垂直交换过程的影响。本章的目的是从水文记录中确定那些对海洋气候“信号”进入和在两个扩散的溢流羽流之间传递至关重要的位置，如果可能的话，追踪这些变化对纽芬兰盆地下游和西部深海边界流以外的影响
The largest full-depth changes in the modern instrumented oceanographic record have taken place in the Labrador Basin of the northwest Atlantic over the last 4 decades. The extreme amplitude of anomalous conditions there and the importance of their claimed effects for the thermohaline circulation and for climate (e.g. Bryden et al. 2005) justify attempts to identify the origin of change throughout the watercolumn of the subpolar Atlantic. At depths in the Labrador Basin greater than the limits of open-ocean deep convection (2,300 m or so), change is necessarily imported to the Basin by the two main dense water overflows that cross the Greenland–Scotland Ridge via the Denmark Strait and Faroe–Shetland Channel. Each of the constituent watermasses that form these overflows (see, for example, Rudels et al. 2002) will carry with them the imprint of time-varying climatic forcing in their source regions and of modificationsen route, and their properties will also be subject to alteration by the processes of horizontal and vertical exchange from their spillways to the Labrador Basin. The purpose of this chapter is to identify from the hydrographic record those locations that are of primary importance for the transfer of ocean climate ‘signals’ into and between the two spreading overflow plumes, and if possible to trace the influence of these changes downstream to the Newfoundland Basin and beyond in the Deep Western Boundary Current