在整个全新纪的极度变化的厄尔尼诺-南方振荡
Kim M Cobb1, Niko Westphal, Hussein R Sayani
1School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA. kcobb@eas.gatech.edu
概括
厄尔尼诺-南方振荡 (ENSO) 在7000年中显示出很高的变化. 当前的气候模型可能难以检测由于自然气候变化的强迫ENSO变化.
科学领域:
- 古气候学 古气候学
- 气候动力学 气候动力学
- 海洋学 海洋学 海洋学
背景情况:
- 厄尔尼诺-南方振荡 (ENSO) 每年显著影响全球气候模式.
- ENSO对人为温室气体排放的敏感性仍然不确定.
- 了解ENSO对强迫的反应对于气候变化预测至关重要.
研究的目的:
- 用化石珊瑚记录分析ENSO的长期变化.
- 评估ENSO对过去自然强迫的反应,并与模型预测进行比较.
- 调查人类对ENSO的影响的潜在可检测性.
主要方法:
- 利用了ENSO活动在过去7000年的化石珊瑚重建.
- 集中分析来自北线岛屿的数据,这是ENSO的一个关键区域.
- 与仪器记录和气候模型输出相比较的古气候ENSO变异.
主要成果:
- 化石珊瑚揭示了过去7000年来ENSO活动的高度变化.
- 没有发现ENSO变异的系统趋势,这与一些以阳光照射为主导的模型相矛盾.
- 20世纪的ENSO变异虽然很高,但在古气候记录中并非前所未有的.
结论:
- 长期的ENSO变化很大,可能会掩盖强迫的气候变化信号.
- 在高度内部变化的背景下,检测ENSO上的人为影响可能具有挑战性.
- 过去的ENSO行为表明了弹性和对外部强迫的复杂反应.
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