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Published on: September 5, 2018
热带和高度大西洋温度在最后一个冰川结束时的同步性
David W Lea1, Dorothy K Pak, Larry C Peterson
1Department of Geological Sciences and Marine Science Institute, University of California, Santa Barbara, CA 93106, USA. lea@geol.ucsb.edu
概括
热带大西洋海面温度 (SST) 紧密跟踪了格陵兰岛和大气中甲在最后一次冰川结束期间的变化. 年轻的干旱期出现了显著的SST下降,与热带融合区的变化有关.
科学领域:
- 古海洋学和古气候学.
- 海洋地球化学 海洋地球化学
- 气候动力学 气候动力学
背景情况:
- 了解过去的气候变化和热带和高度地区之间的同步性对于预测未来的气候变化至关重要.
- 卡里亚科盆地提供了一个宝贵的档案,用于重建过去的海面温度 (SSTs),因为它独特的沉积环境.
- 最后一个冰川的终结和年轻的Dryas事件代表了快速气候变化的关键时期.
研究的目的:
- 创建一个高分辨率的海面温度 (SST) 记录从西部热带大西洋在最后一个冰川终结期间.
- 为了将热带SST变化的时间与高度气候代理和大气中甲度进行比较.
- 调查推动热带和高度之间同步气候变化的机制.
主要方法:
- 来自卡里亚科盆地沉积物核心的浮游生物中Mg/Ca比率的分析.
- 开发一个高分辨率的海面温度 (SST) 代理记录.
- SST记录与现有的格陵兰冰盖项目2空气温度和大气甲记录的相关性.
主要成果:
- 在最后一次冰川终结期间,热带大西洋的SST变化与格陵兰的空气温度和大气中的甲同步,在+/-30到+/-90年内.
- 在热带SSTs中发生了3-4°C的显著冷却事件,发生在年轻的干旱期间隔.
- 这些降冰事件的时间表明,热带间汇聚区 (ITCZ) 迅速向南移动.
结论:
- 热带大西洋SSTs在最后一次冰川终结期间对主要的气候变化做出了快速和同步的反应,包括年轻的Dryas.
- 南方ITCZ转移是一个合理的机制,将热带温度,大气中的甲和高度气候变化联系在一起.
- 这项研究强调了地球气候系统在快速降冰时期的相互联系.
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