热带太平洋地下温度的突然变化与厄尔尼诺现象的变化有关
1T. P. Guilderson, Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, USA, and Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA. D. P. Sc.
概括
加拉巴哥群岛地表水中的放射性碳含量在1976年后急剧上升,这与海面温度的变化相吻合. 这表明东部热带太平洋的变化.
科学领域:
- 海洋学 海洋学 海洋学
- 古气候学 古气候学
- 通过放射性碳测年法进行测年.
背景情况:
- 厄尔尼诺南部振荡 (ENSO) 显著影响全球气候.
- 了解过去的ENSO动态对于预测未来事件至关重要.
- 珊瑚记录为重建过去的海洋条件提供了有价值的代理信息.
研究的目的:
- 在东部热带太平洋地区调查表面水的放射性碳 (14C) 和海面温度 (SST) 的变化.
- 确定这些变化的时间和影响,特别是在1976年厄尔尼诺事件之后.
- 评估观察到的变化与ENSO行为之间的潜在联系.
主要方法:
- 从珊瑚记录中分析放射性碳 (14C) 含量.
- 从相同的珊瑚记录中重建海面温度 (SST).
- 14C和SST数据与季节性和基于事件的气候数据的相关性.
主要成果:
- 1976年以后,在上游季节 (7月至9月) 观察到表面水中14C含量的显著,急剧增加.
- 在上升季节的海面温度 (SSTs) 也呈现出1976年后明显的变化.
- 观察到的14C和SST的变化是同步的,表明东热带太平洋的垂直热结构发生了变化.
结论:
- 1976年厄尔尼诺事件标志着东部热带太平洋海洋学条件的关键变化.
- 改变的垂直热结构可能影响了随后厄尔尼诺现象的频率和强度.
- 这项研究强调了热带太平洋对气候变化的敏感性及其对ENSO的影响.
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