北半球气候的高分辨率记录延伸到最后的间冰期
K K Andersen1, N Azuma, J-M Barnola
1Niels Bohr Institute for Astronomy, Physics and Geophysics, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen OE, Denmark.
Nature
|September 10, 2004
概括
一个新的北格陵兰冰芯揭示了在最后一个间冰期期间的稳定,更温暖的气候. 这个记录详细介绍了最后一个冰川时期的开始和一个未知的突然变暖事件.
科学领域:
- 古气候学 古气候学
- 冰川学的冰川学
- 气候科学 气候科学
背景情况:
- 中部格陵兰岛的冰芯对于北半球气候重建至关重要.
- 这些核心的较旧部分由于冰折叠而出现了时间上的干扰.
- 需要一个连续的,不受干扰的气候记录,从最后的间冰期.
研究的目的:
- 为了呈现一个不受干扰的气候记录从一个北格陵兰冰芯跨越了最后一个间冰期.
- 为了重建这个时期的温度和气候稳定性.
- 调查半球气候动态和最后一个冰川时期的开始.
主要方法:
- 在格陵兰岛北部深层冰芯的钻探和分析.
- 氧同位素分析以重建过去的温度.
- 冰芯部分的年代测算.
主要成果:
- 一个不受干扰的气候记录,可以追溯到现在之前的123,000年.
- 稳定的气候条件,在最后一个冰河间时期,温度比今天高5°C.
- 证据表明,大约115,000年前,一个以前未知的突然变暖事件发生了.
- 北部和中部格陵兰的气温记录之间存在显著的温度差异,这表明北半球的冰面范围调节了度温度梯度.
- 缓慢的温度下降标志着最后一个冰川时期的开始.
- 缺乏对突然变暖事件的直接南极对应物,表明不同的半球气候相互作用.
结论:
- 最后一个冰河间时期的特点是格陵兰的气候稳定,比现在更温暖.
- 北半球的冰面影响了格陵兰的度温度梯度.
- 在最后一个冰川时期完全发展之前,发生了一种未被识别的突然变暖事件.
- 在这个特定的过渡期间,半球间气候看看机制可能没有占主导地位.
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