Reconstructing the southern South China Sea upper water column structure since the Last Glacial Maximum: Implications for the East Asian winter monsoon development
Reconstructing the southern South China Sea upper water column structure since the Last Glacial Maximum: Implications for the East Asian winter monsoon development
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DOI：
10.1029/2009pa001850
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发表时间：
2010-06
期刊：
影响因子：
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通讯作者：
S. Steinke;M. Mohtadi;J. Groeneveld;Li-Chuan Lin;L. Löwemark;Min‐Te Chen;R. Rendle-Buehring
中科院分区：
文献类型：
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作者：
S. Steinke;M. Mohtadi;J. Groeneveld;Li-Chuan Lin;L. Löwemark;Min‐Te Chen;R. Rendle-Buehring
表层浮游有孔虫 (G. ruber) 和温跃层浮游有孔虫 (P. obliquiloculata) 的稳定氧同位素 (Dd 18 O) 和 Mg/Ca 温度 (DT) 差异，以及烯酮和 P. obliquiloculata Mg/Ca 温度之间的温差，以估计国际海洋过去全球变化研究 (IMAGES) 核心的上层海洋温度梯度MD01-2390。上层海洋温度梯度的估计被用来重建混合层动力学。我们发现我们的 Dd 18 O 估计值因盐度变化而存在偏差，因此无法显示真正的上层海洋温度梯度。 D 至 fG。 ruber 和 P. obliquiloculata 以及烯酮和 P. obliquiloculata 表明晚冰期期间地表水混合增加，可能是由于 EAWM 风增强。全新世晚期地表水混合较弱，表明冬季季风的影响较弱。冬季风活动最弱发生在6.5ka至2.5ka之间。自末次盛冰期以来推断的 EAWM 变化与中国黄土沉积物中记录的 EAWM 变化一致。我们发现，东亚冬季风和东亚夏季风的强度在末次冰期和冰消期表现出相反的行为，但在中晚全新世期间表现出共变。
difference in the stable oxygen isotopes (Dd 18 O) and Mg/Ca‐based temperatures (DT) of surface‐dwelling (G. ruber) and thermocline‐dwelling (P. obliquiloculata) planktonic foraminifera and the temperature difference between alkenone‐ and P. obliquiloculata Mg/Ca‐based temperatures to estimate the upper ocean thermal gradient at International Marine Past Global Change Study (IMAGES) core MD01‐2390. Estimates of the upper ocean thermal gradient were used to reconstruct mixed layer dynamics. We find that our Dd 18 O estimates are biased by changes in salinity and, thus, do not display a true upper ocean thermal gradient. The D To fG. ruber and P. obliquiloculata as well as the alkenone and P. obliquiloculata suggest increased surface water mixing during the late glacial, likely due to enhanced EAWM winds. Surface water mixing was weaker during the late Holocene, indicating a weaker influence of winter monsoon winds. The weakest winter monsoon activity occurred between 6.5 ka and 2.5 ka. Inferred EAWM changes since the Last Glacial Maximum coincide with EAWM changes as recorded in Chinese loess sediments. We find that the intensity of the EAWM and the East Asian summer monsoon show an inverse behavior during the last glacial and deglaciation but covaried during the middle to late Holocene.