由于小冰河时代的冷却,热带太平洋的动态刺激和ENSO的变化
Gerald T Rustic1, Athanasios Koutavas2, Thomas M Marchitto3
1Department of Engineering Science and Physics, College of Staten Island, City University of New York, Staten Island, NY 10314, USA. Doctoral Program in Earth and Environmental Sciences, Graduate Center of the City University of New York, New York, NY 10016, USA. grustic@ldeo.columbia.edu.
概括
从加拉帕戈斯岛沉积物的古气候记录显示,在中世纪气候异常和小冰河时期,热带太平洋的动态发生了变化. 千年中期的转变显示了厄尔尼诺-南方振荡活动的放大和渐变的减弱.
科学领域:
- 古代海洋学
- 气候科学
- 海洋与大气的动态
背景情况:
- 了解过去热带太平洋的动态对于气候建模至关重要.
- 在中世纪气候异常 (MCA) 和小冰河时代 (LIA) 中,东方赤道太平洋的古气候数据有限.
研究的目的:
- 重建过去的海面温度,厄尔尼诺-南方振荡 (ENSO) 活动和热带太平洋的区域梯度.
- 在MCA和LIA期间调查海洋-大气循环变化.
主要方法:
- 从加拉帕戈斯岛的沉积物核心分析.
- 对海面温度和ENSO活动的古海洋学代理数据的重建.
主要成果:
- 大约在公元1500-1650年,发生了千年中期的转变 (MMS),从湿化ENSO和强的区域梯度过渡到放大ENSO和弱梯度.
- 这次MMS与LIA最深度的降温相吻合,可能是由热带融合区向南移动所驱动.
- 西元900- 1150年的MCA峰期的特点是东太平洋的温暖条件,挑战了持续的拉尼娜模式的概念.
结论:
- 东方赤道太平洋在MCA和LIA期间经历了显著的海洋大气循环变化.
- 气候变化与ENSO活动的变化以及热带融合区的位置有关.
- 过去的气候重建挑战了热带太平洋在关键古气候间隔中的现有模式.
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