直接测量北大西洋东北部的中深循环
A S Bower1, B Le Cann, T Rossby
1Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA. abower@whoi.edu
Nature
|October 11, 2002
概括
海流对全球气候产生重大影响. 新数据揭示了温暖的水如何向北流动,以及海底地形如何控制北大西洋的海洋循环.
科学领域:
- 海洋学 海洋学 海洋学
- 气候科学 气候科学
- 地质物理学 地质物理学
背景情况:
- 海洋循环,特别是热传输,对于全球气候调节至关重要.
- 卫星观测仅限于地表水域,使得深海海流的测量不足.
- 准确测量深海循环对于气候建模至关重要.
研究的目的:
- 在东北北大西洋的两个不同的深度量化水体的绝对速度.
- 研究来自亚热带地区和地中海的热水运输的途径和范围.
- 为了确定海底地形对深海海流模式的影响.
主要方法:
- 部署声学跟踪浮标,以全面,直接观察深海海流.
- 在约600米深度 (热带) 和另一个更深层次的绝对速度的定量映射.
- 分析与中大西洋山脊及其地形特征有关的当前路径.
主要成果:
- 通过海湾流系统向北传输的大部分热量都停留在亚极区内,进入罗卡尔海峡或北欧海域的入口有限.
- 温暖的,盐的地中海外流通过狭窄的斜坡流和混合,挑战以前的假设,到达高度.
- 海流始终在深处穿过中大西洋山脊,表明了对流通的地形控制.
结论:
- 深海循环模式受到海底地形的显著影响,特别是在中大西洋山脊.
- 了解这些深流对于准确的气候变化预测和海洋学模型至关重要.
- 温暖,盐水到高度的运输机制已经通过这项研究得到了改进.
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