基于EEMD方法的全新世亚洲季风石笋氧碳同位素对比研究

发布时间：2018-04-14 11:14

  本文选题：集合经验模态分解(EEMD) + 全新世　； 参考：《地理研究》2017年08期

【摘要】：采用集合经验模态分解方法(EEMD),对贵州省董哥洞全新世石笋δ~(18)O、δ~(13)C记录进行多尺度分解,分别获得8、9个本征模分量。在254 a以下尺度上,石笋δ~(13)C和δ~(18)O的本征模分量基本一致,其中254 a和116 a两个周期都类似于大气Δ~(14)C表征的太阳活动周期,表明植被生产力和低纬水汽都受控于太阳活动。同一周期对应的δ~(13)C振幅几乎是δ~(18)O的2倍,说明洞穴地点的土壤生产率放大了太阳活动的初始信号。526 a周期对石笋δ~(13)C贡献最大(~20%),与北大西洋深层水体550 a周期一致,可能的机制是北半球高纬气候通过西风带影响了东亚大陆的环境变化。石笋δ~(13)C的趋势分量变化平稳,明显不同于δ~(18)O的趋势分量,表明洞穴地点的土壤生产率并不直接响应于轨道尺度的太阳辐射变化。
[Abstract]:By using the method of empirical mode decomposition (EMD), the multiscale decomposition of the Holocene stalagmites 未 ~ (18) O and 未 ~ (13) ~ (13) C records of Donggodong, Guizhou Province was carried out, and the eigenmode components of 8 and 9 intrinsic modes were obtained respectively.On the scale below 254 years, the intrinsic mode components of stalagmite 未 ~ (13) ~ (13) C and 未 ~ (18) O are basically the same. The periods of 254a and 116a are both similar to the solar cycle characterized by atmospheric 螖 ~ (14) C, indicating that vegetation productivity and low latitude water vapor are controlled by solar activity.The amplitude of 未 ~ (13) C corresponding to the same period is almost twice that of 未 ~ (18) O, which indicates that the initial signal of solar activity .526 a period is magnified by soil productivity in the cave site, and the maximum contribution to 未 ~ (13) ~ (13) C of stalagmites is obtained from the period of .526 a, which is consistent with the 550 a cycle of deep North Atlantic water bodies.The possible mechanism is that the high latitudes of the Northern Hemisphere influence the environmental changes of the East Asian continent through the westerly belt.The trend component of stalagmite 未 ~ (13) C is stable, which is obviously different from that of 未 ~ (18) O, indicating that the soil productivity in the cave site is not directly related to the solar radiation variation on the orbital scale.
【作者单位】： 南京师范大学地理科学学院虚拟地理环境教育部重点实验室;江苏省地理环境演化国家重点实验室培育建设点;江苏省地理信息资源开发与利用协同创新中心;
【基金】：国家自然科学基金项目(41130210,41572340) 江苏高校优势学科建设工程资助项目(164320H116)
【分类号】：P532
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本文编号：1749056