证据表明,在深海海洋的粗地形上,混合的程度提高了
1Woods Hole Oceanographic Institution, Massachusetts 02543, USA. jledwell@whoi.edu
Nature
|January 26, 2000
概括
海洋混合是气候调节的关键. 这项研究揭示了深山丘上方的动荡混合物显著增强了垂直水运输,可能会关闭全球海洋,颠覆循环预算.
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:
- 海洋翻转循环对于全球气候调节至关重要.
- 深海水运输的机制已被理解,但上升补偿运输仍然不清楚.
- 流混合是上升水运输的唯一可行的机制,但以前测量的速度太低了.
研究的目的:
- 调查巴西盆地流混合的机制和速度.
- 为了确定观察到的混合速率是否足以解释海洋的回流.
- 评估这种混合在关闭全球翻转循环中的作用.
主要方法:
- 测量标记剂分散的测量.
- 测量流能量消散率的测量.
- 分析内部波场及其与浴度学相互作用.
主要成果:
- 在深山丘以上的500米深度测量了2-4cm2s(-1) 的扩散度.
- 在靠近海洋底部的地方观察到大约10cm2s(-1) 的扩散度.
- 这些混合率明显高于之前报告的值.
结论:
- 突破内部波浪,由潮电流在粗的水度上产生的,可能驱动增强混合.
- 观察到的混合率可能足以平衡巴西盆地的浮力预算.
- 这种增强的混合提供了关闭全球翻转循环的潜在机制.
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