| 最后4个冰期旋回中国黄土记录的东亚冬季风变化 |
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| 引用本文： | 孙有斌,安芷生.最后4个冰期旋回中国黄土记录的东亚冬季风变化[J].地球科学,2002,27(1):19-24. |
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| 作者姓名： | 孙有斌 安芷生 |
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| 作者单位： | 1.中国科学院地球环境研究所, 陕西西安 710075 |
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| 基金项目： | 国家重点基础研究发展规划项目 (G19990 4340 1)，国家自然科学基金项目 (No .4982 30 0 1,49972 0 5 6 ) |
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| 摘 要： | 开展高分辨率的黄土记录研究, 是揭示过去气候变迁和变率的主要途径.选择黄土高原中部的灵台和赵家川剖面, 对L5以上的黄土-古土壤序列进行了石英颗粒的提取和粒度分析.结果表明, 石英粗颗粒(> 43μm) 体积分数变化揭示了最后4个冰期旋回东亚冬季风存有的快速变化特征, 并同深海氧同位素记录具有良好的对应关系; 然而, 在每一个冰期时段, 石英粗颗粒体积分数的变化幅度和频率存有较大差异, 可能意味着对应的冰期下垫面状况和气候系统内部的非线性响应机制并不相同.值得注意的是由石英粗颗粒体积分数反映的东亚冬季风变化, 在某些时段不仅同磁化率记录的夏季风变化不协调, 而且同深海氧同位素记录存有明显差异.深入研究这种由不同代用指标反映的古气候变化间的差异, 对理解黄土记录的全球性意义显得尤为重要.
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| 关 键 词： | 东亚冬季风 快速变化 最后4个冰期旋回 中国黄土 |
| 文章编号： | 1000-2383(2002)01-0019-06 |
| 收稿时间： | 2001-03-20 |
Variation of the East Asian Winter Monsoon Recorded by Chinese Loess during the Last Four Glacial-Interglacial Cycles |
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| Sun Youbin ,An Zhisheng.Variation of the East Asian Winter Monsoon Recorded by Chinese Loess during the Last Four Glacial-Interglacial Cycles[J].Earth Science-Journal of China University of Geosciences,2002,27(1):19-24. |
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| Authors: | Sun Youbin An Zhisheng |
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| Institution: | Sun Youbin 1,2,An Zhisheng 1 |
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| Abstract: | Study on the high resolution loess record from the Chinese loess plateau is the main approach to reveal the past climatic change and variability. The undisturbed and continuous accumulation of the loess deposits has provided an opportunity to develop complete and high resolution records of terrestrial climate changes over multiple glacial interglacial cycles during the past 7 million years. In the present paper, Lingtai and Zhaojiachuan profiles from the central loess plateau were studied down to loess unit L5, formed during the last four glacial interglacial cycles. Quartz grains were extracted by chemical methods for grain size analysis, and the grain size data indicate that coarse quartz volume fraction could be considered as the reliable proxy of the East Asian winter monsoon. Changes in the content of coarse quartz volume fraction have documented the high frequency variability of winter monsoon during the last four glacial interglacial cycles and can be well correlated to the marine δ(18O) record, whereas the content of the coarse quartz volume fraction variation shows a different variability during every glacial period that may indicate the various underlying conditions and non linear responses during the last four glaciations. It is worthwhile to note that in some cases the variation of coarse quartz volume fraction exhibits a disagreement with both magnetic susceptibility variation and the marine oxygen isotope curves. Such disparity of the past climate changes revealed by different proxy records is very important for understanding the global significance of Chinese loess and thus requires further investigation. |
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| Keywords: | East Asian winter monsoon variation last four glacial interglacial cycles Chinese loess |
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