加勒比海和北大西洋的盐度变化之间的联系热环循环
Matthew W Schmidt1, Howard J Spero, David W Lea
1Department of Geology, University of California, Davis, California 95616, USA. schmidt@geology.ucdavis.edu
Nature
|March 12, 2004
概括
加勒比海盐度在最后一个冰川周期期间与北大西洋深水形成波动. 较低的盐度先于变暖事件,表明热带水的吸引力放大了气候变化.
科学领域:
- 古海洋学是古海洋学.
- 气候科学 气候科学
- 海洋学 海洋学 海洋学
背景情况:
- 热haline循环强度通过调节海洋热传输来影响气候.
- 北大西洋深水 (NADW) 形成是全球海洋循环和气候调节的关键组成部分.
- 热环流的过去变化与冰川周期期间的快速气候变化有关.
研究的目的:
- 为了重建最后一个冰川周期期间的热带大西洋表面盐度.
- 研究加勒比海盐度,NADW形成和气候变化之间的关系.
- 了解热带水向导在推动北大西洋气候变化的作用.
主要方法:
- 对两个加勒比海沉积物核心的分析.
- 使用Mg/Ca古热度计来重建海面温度.
- 氧同位素测量在酸中,以确定表面盐度.
主要成果:
- 加勒比海的表面盐度波动,在寒冷阶段显示盐度较高的条件 (2,4,6),在温暖阶段显示盐度较低的条件 (3,5).
- 这些盐度变化与NADW形成强度的重建变化共变.
- 加勒比海盐度的急剧下降发生在博林/阿勒罗德温暖区间开始时.
结论:
- 加勒比海的表面盐度是NADW形成强度的可靠指标.
- 盐酸热带水流入北大西洋可能会扩大热环流.
- 这种放大有助于显著的高度变暖事件,如Bølling/Allerød.
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