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冰川气候的快速变化模拟在一个结合的气候模型
1Potsdam Institute for Climate Impact Research, Germany. ganopolski@pik-potsdam.de
Nature
|February 24, 2001
概括
由于边缘不稳定的温暖的海洋循环模式,冰川气候变化很大. 这个模型解释了像Dansgaard-Oeschger和Heinrich事件这样的突然气候变化,与稳定的Holocene不同.
科学领域:
- 古气候学 古气候学
- 气候建模 气候建模
- 海洋学 海洋学 海洋学
背景情况:
- 最后一个冰川时期经历了突然的气候变化 (丹斯加德-奥什格尔和海因里希事件),与全新世纪的稳定性形成鲜明对比.
- 了解冰川气候变化背后的机制对于预测未来气候动态至关重要.
研究的目的:
- 用中等复杂度的气候模型研究冰川气候的稳定性.
- 为了解释在最后一个冰川时期发生的突然气候事件的发生.
主要方法:
- 利用中等复杂度的气候模型来模拟冰川气候动态.
- 在不同的大西洋循环模式上进行稳定性分析.
主要成果:
- 确定了大西洋循环的单一稳定的冷模式,冰岛以南的深水形成.
- 一个"温暖"的循环模式,类似于今天的条件,被发现是边际不稳定的.
- 暂时过渡到温暖模式触发了类似于丹斯加尔德-奥什格事件的突然变暖事件.
- 模拟的大量淡水输入 (冰山释放) 暂时停止了深水的形成,导致格陵兰的冷却和南极的变暖,与海因里希事件一致.
结论:
- 温暖的大西洋循环模式的边际不稳定性提供了突然冰川气候变化的机制.
- 该模型的发现解释了与Holocene相比,冰川气候的变化更大.
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