East Asian monsoon variability since the Mid-Holocene recorded in a high-resolution, absolute-dated aragonite speleothem from eastern China
East Asian monsoon variability since the Mid-Holocene recorded in a high-resolution, absolute-dated aragonite speleothem from eastern China
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DOI：
10.1016/j.epsl.2008.08.018
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发表时间：
2008-11-15
影响因子：
5.3
通讯作者：
Cheng, Hai
中科院分区：
文献类型：
--
作者：
Cosford, Jason;Qing, Hairuo;Cheng, Hai
利用来自湖南莲花洞的文石石笋的O-18值(819个测量值)重建了全新世中晚期与东亚季风有关的古气候条件。DELTA O-18值(-1.6‰~-7.0‰)反映了与夏季风环流强度有关的降水量效应。在整个过程中，东亚夏季风环流强度随着日照强度的变化和热带辐合带(ITCZ)的南移而减弱。突出这种一阶趋势的是从千年到十年尺度的突然波动，其中最突出的发生在3337+/-5年BP左右，记录了夏季风环流的急剧减弱，与新冰川条件的开始相吻合。石笋A1的O-18值与前人发表的和尚洞HS-4石笋和中国东葛洞D4和DA石笋的O-18值比较，显示出相似的区域响应东亚季风环流变化。应用多种频谱分析技术和小波分析技术对这些石笋记录进行了分析，以评价全新世东亚季风旋回的性质和特征。多锥法(MTM)、Lomb-Scargle和单谱分析(SSA)结果揭示了常见的周期，这些周期不太可能是任何单一技术的伪像。石笋三角洲O-18记录所表现出的周期性既发生在太阳频率上，也发生在非太阳频率上，支持了以前关于季风环流变化既响应太阳强迫又响应内部气候机制的解释。小波分析表明，其中一些频率是间歇的，并以半规则的间隔重复出现，这可能表明了不受记录年代学限制的长期周期性。(C)2008爱思唯尔B.V.保留所有权利。
Paleoclimatic conditions associated with the East Asian monsoon are reconstructed for the Mid- to Late-Holocene using delta O-18 values (819 measurements) from a precisely dated (10 Th-230 dates) aragonite stalagmite from Lianhua Cave, Hunan Province, China. delta O-18 values (-1.6 parts per thousand to -7.0 parts per thousand) are interpreted to reflect the precipitation amount effect related to the strength of summer monsoonal circulation. Throughout this period, the intensity of East Asian summer monsoonal circulation declined in response to changes in insolation and a southward shift in the Intertropical Convergence Zone (ITCZ). Punctuating this first-order trend are abrupt millennial- to decadal-scale fluctuations, the most prominent of which occurred around 3337 +/- 5 yr BP and records a dramatic weakening in summer monsoonal circulation that coincides with the beginning of Neoglacial conditions. Comparisons between the delta O-18 values of stalagmite A1 and previously published data from stalagmite HS-4 from Heshang Cave and stalagmites D4 and DA from Dongge Cave, China, demonstrate a similar regional response to changes in East Asian monsoonal circulation. Several spectral analysis techniques and wavelet analysis were applied to these stalagmite records to evaluate the nature and character of cyclicity in the East Asian monsoon during the Holocene. Multi-Taper Method (MTM), Lomb-Scargle, and Single Spectrum Analysis (SSA) results reveal common periodicities that are unlikely to be artifacts of any single technique. The periodicities expressed in the stalagmite delta O-18 records occur at both solar and non-solar frequencies and support previous interpretations that variability in monsoonal circulation responds to both solar forcing and internal climatic mechanisms. Wavelet analysis demonstrates that some of these frequencies are intermittent and recur at semi-regular intervals, which may indicate long-term cyclicity that is unconstrained by the chronology of the record. (c) 2008 Elsevier B.V. All rights reserved.