基于EEMD方法的全新世亞洲季風(fēng)石筍氧碳同位素對(duì)比研究
發(fā)布時(shí)間:2018-04-14 11:14
本文選題:集合經(jīng)驗(yàn)?zāi)B(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(yàn)?zāi)B(tài)分解方法(EEMD),對(duì)貴州省董哥洞全新世石筍δ~(18)O、δ~(13)C記錄進(jìn)行多尺度分解,分別獲得8、9個(gè)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(gè)周期都類(lèi)似于大氣Δ~(14)C表征的太陽(yáng)活動(dòng)周期,表明植被生產(chǎn)力和低緯水汽都受控于太陽(yáng)活動(dòng)。同一周期對(duì)應(yīng)的δ~(13)C振幅幾乎是δ~(18)O的2倍,說(shuō)明洞穴地點(diǎn)的土壤生產(chǎn)率放大了太陽(yáng)活動(dòng)的初始信號(hào)。526 a周期對(duì)石筍δ~(13)C貢獻(xiàn)最大(~20%),與北大西洋深層水體550 a周期一致,可能的機(jī)制是北半球高緯氣候通過(guò)西風(fēng)帶影響了東亞大陸的環(huán)境變化。石筍δ~(13)C的趨勢(shì)分量變化平穩(wěn),明顯不同于δ~(18)O的趨勢(shì)分量,表明洞穴地點(diǎn)的土壤生產(chǎn)率并不直接響應(yīng)于軌道尺度的太陽(yáng)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(xué)地理科學(xué)學(xué)院虛擬地理環(huán)境教育部重點(diǎn)實(shí)驗(yàn)室;江蘇省地理環(huán)境演化國(guó)家重點(diǎn)實(shí)驗(yàn)室培育建設(shè)點(diǎn);江蘇省地理信息資源開(kāi)發(fā)與利用協(xié)同創(chuàng)新中心;
【基金】:國(guó)家自然科學(xué)基金項(xiàng)目(41130210,41572340) 江蘇高校優(yōu)勢(shì)學(xué)科建設(shè)工程資助項(xiàng)目(164320H116)
【分類(lèi)號(hào)】:P532
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本文編號(hào):1749056
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