基于EEMD方法的全新世亞洲季風石筍氧碳同位素對比研究
發(fā)布時間:2018-04-14 11:14
本文選題:集合經(jīng)驗模態(tài)分解(EEMD) + 全新世; 參考:《地理研究》2017年08期
【摘要】:采用集合經(jīng)驗模態(tài)分解方法(EEMD),對貴州省董哥洞全新世石筍δ~(18)O、δ~(13)C記錄進行多尺度分解,分別獲得8、9個本征模分量。在254 a以下尺度上,石筍δ~(13)C和δ~(18)O的本征模分量基本一致,其中254 a和116 a兩個周期都類似于大氣Δ~(14)C表征的太陽活動周期,表明植被生產(chǎn)力和低緯水汽都受控于太陽活動。同一周期對應(yīng)的δ~(13)C振幅幾乎是δ~(18)O的2倍,說明洞穴地點的土壤生產(chǎn)率放大了太陽活動的初始信號。526 a周期對石筍δ~(13)C貢獻最大(~20%),與北大西洋深層水體550 a周期一致,可能的機制是北半球高緯氣候通過西風帶影響了東亞大陸的環(huán)境變化。石筍δ~(13)C的趨勢分量變化平穩(wěn),明顯不同于δ~(18)O的趨勢分量,表明洞穴地點的土壤生產(chǎn)率并不直接響應(yīng)于軌道尺度的太陽輻射變化。
[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.
【作者單位】: 南京師范大學地理科學學院虛擬地理環(huán)境教育部重點實驗室;江蘇省地理環(huán)境演化國家重點實驗室培育建設(shè)點;江蘇省地理信息資源開發(fā)與利用協(xié)同創(chuàng)新中心;
【基金】:國家自然科學基金項目(41130210,41572340) 江蘇高校優(yōu)勢學科建設(shè)工程資助項目(164320H116)
【分類號】:P532
,
本文編號:1749056
本文鏈接:http://www.wukwdryxk.cn/kejilunwen/diqiudizhi/1749056.html
最近更新
教材專著