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在中度的最后一个冰川最大的近同步的半球间终结
Joerg M Schaefer1, George H Denton, David J A Barrell
1Lamont-Doherty Earth Observatory (L-DEO), Palisades, NY 10964, USA. schaefer@ldeo.columbia.edu
概括
在最后一个冰期结束时的全球变暖是异步的,但中度冰川的撤退在两个半球同时开始. 这表明全球气温上升被北大西洋寒冷的冬季所掩盖.
科学领域:
- 古气候学 古气候学
- 冰川学的冰川学
- 地质时间学 (Geochronology)
背景情况:
- 来自极地冰芯的同位素记录表明,在最后一次冰期之后,全球变暖异步.
- 以前的研究表明,半球脱冰的时间表在半球之间有所不同.
研究的目的:
- 为了研究最后一个冰川最大期结束时中度冰川撤退的时间.
- 为了使明显的异步全球变暖与同步的冰川撤退相协调.
主要方法:
- 使用了10Be (柏利-10) 暴露,用于冰川的退缩.
- 分析了来自极地冰芯的同位素记录,以获得温度和大气CO2数据.
主要成果:
- 10Be暴露年代测定揭示了两半球中度冰川的同步大规模撤退.
- 冰川撤退的时间与南极冰芯数据一致,显示温度和CO2的增加.
- 北大西洋地区经历过极寒的冬季,由于海冰的广泛存在,可能会掩盖全球变暖的趋势.
结论:
- 最后冰川最大期结束时的全球变暖趋势在某些地区可能被局部气候异常所掩盖.
- 同步的冰川撤退支持全球协调的变暖事件,尽管区域差异.
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