北极冰盖在40万年内在阳光照射变化最小值期间积累的延迟
Qingzhen Hao1, Luo Wang, Frank Oldfield
1Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China. haoqz@mail.iggcas.ac.cn
Nature
|October 5, 2012
概括
来自中国洛斯高原的过去气候数据显示,弱弱的东亚冬季季风 (EAWM) 在北极延长了温和的非冰川条件. 这一发现为未来气候变化情景提供了洞察力.
科学领域:
- 古气候学 古气候学
- 四年纪地质学四年纪地质学
- 气候动力学 气候动力学
背景情况:
- 了解北部高度地区过去的气候变化对于预测未来的气候变化至关重要.
- 北半球冰盖的长期记录很少;谷底 (18) O记录整合了两极冰体积.
- 东亚冬季季风 (EAWM) 受北半球冰盖的影响,可以作为北极气候变化的代理.
研究的目的:
- 用EAWM作为代理来重建过去的北极气候变化.
- 研究冰河间时期的持续时间和特征以及它们对北方高度的影响.
主要方法:
- 在过去的90万年中,分析了中国洛斯高原洛斯部分的谷粒大小变化.
- 使用太空尘埃沉积物作为EAWM强度的代理.
- 将EAWM变化与天文周期 (离心率和前行) 相关联.
主要成果:
- 一个90万年的EAWM代理记录是使用洛斯谷粒大小数据建立的.
- 在特定的40万年周期中,EAWM的弱势持续了多达20,000年.
- 这与大多数其他间冰期之后EAWM的快速增加形成鲜明对比.
结论:
- 由于西伯利亚高峰活动减少,EAWM弱风的推动下,北极的温和条件比以前想象的要长.
- 这种延长的非冰期与65°N的较弱的夏季阳光最小值有关,抑制了冰的积累.
- 这些发现挑战了关于冰川间到冰川间过渡的传统和海洋氧同位素记录.
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