从南极冰芯开始的八个冰川周期
Laurent Augustin1, Carlo Barbante, Piers R F Barnes
1Laboratoire de Glaciologie et Géophysique de l'Environnement, CNRS, BP 96, 38402 St Martin d'Hères Cedex, France.
Nature
|June 11, 2004
概括
一个新的南极冰芯揭示了74万年的气候历史. 这份记录显示,过去的间冰期更长,更温暖,为自然气候变化和温室气体循环提供了洞察力.
科学领域:
- 古气候学 古气候学
- 冰核科学 冰核科学
- 气候反是气候的反.
背景情况:
- 南极冰芯,像Vostok一样,提供了数十万年来关键的气候数据.
- 海洋记录的分辨率有限,无法确定大气中的温室气体度.
- 以前的记录可以追溯到420,000年前,有迹象表明在这个时期之前气候变化较低.
研究的目的:
- 重建一个超出沃斯托克核心范围的气候记录.
- 为了分析过去74万年的温室气体度和温度变化.
- 为了比较过去的冰川 - 冰川间周期与当前的冰川间时期.
主要方法:
- 来自南极洲C圆顶的深层冰芯的回收和分析.
- 对被困大气气体和冰层内的同位素组成进行约会和分析.
- 新的冰芯记录与现有的古气候数据进行比较,包括沃斯托克记录.
主要成果:
- 圆顶C冰芯提供了覆盖74万年的气候记录,证实了过去四个冰川周期的沃斯托克记录.
- 在74万至43万年前的时期,冰川间的温暖程度较低,但温暖阶段的持续时间较长.
- 约43万年前的终结V显示了温度和温室气体变化与当前过渡的相似之处,但有不同的模式.
- 结束V之后的间冰期持续了大约28,000年,比目前的间冰期要长得多.
结论:
- 过去的冰川间时期,特别是V期结束后的冰川间时期,比现在的冰川间时期长得多.
- 过去温暖时期的持续时间延长表明,长期稳定的温暖气候可能在没有人为影响的情况下出现.
- 了解过去的气候动态,包括天然温室气体循环和温度变化,对于预测未来的气候轨迹至关重要.
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