East Asian monsoon climate during the Late Pleistocene: high-resolution sediment records from the south China Sea
East Asian monsoon climate during the Late Pleistocene: high-resolution sediment records from the south China Sea
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DOI：
10.1016/s0025-3227(98)00182-0
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发表时间：
1999-03-15
期刊：
影响因子：
2.9
通讯作者：
Pflaumann, U
中科院分区：
文献类型：
--
作者：
Wang, L;Sarnthein, M;Pflaumann, U
通过对南海中国海区10个沉积物柱样和40个柱顶样品的研究，获得了近22万年来东亚季风气候在千年至双年尺度上变化的替代记录。根据浮游和海底稳定同位素记录、硅屑粒度分布、浮游有孔虫种类和U-37(K)生物标志物指数，得出了全球海平面、表层水中古温度、盐度和营养物质的估计、深水通风、古风强度、淡水盖层、河流和(或)风沙沉积物供应以及海底沉积物风吹等气候指标。四个岩心的年代是AMS-C-14。在过去的两个冰川周期中，两种不同的季风环流模式主导着南海，它们与北半球太阳辐射的最小和最大值有关。(1)冰期导致稳定的河口环流和通过关闭婆罗洲海峡而形成的强O-2极小层。冬季出现强烈的东北季候风和凉爽的地表水，部分原因是来自吕宋岛北端的流入。相比之下，夏季的气温与间冰期一样高，因此季节性很强。亚热带南部的低湿度中国反对来自涌现的舜他陆架的大河流输入，作为热带森林的冰川避难所。(2)间冰期夏季暖水通过婆罗洲海峡流入强烈，越南东南上升流强烈，中国大陆湿润，东北季风减弱，冬季海温偏高，季节性偏低。除了千年至百年尺度的长期变化外，我们还发现了全新世、冰川终止I和II以及阶段3期间的冷干和暖湿时期。这些时期与已公布的印度季风变化相同，并可能与格陵兰冰芯记录的寒冷的Heinrich和温暖的Dansgaard-Oeschger事件相同，因此表明全球气候遥相关。南中国径流的全新世振荡以775年为周期，归因于海洋温盐环流1500年周期的次谐波。102/84年周期暂定为太阳活动的Gleissberg周期。不同季风指标之间的位相关系表明，夏季风降水和来自中国南部的河流径流在末次冰期最大日照最小值之后就已经加强，与全球海平面上升的三角洲(18)O信号之前南极冰川融化开始同龄。反之亦然，仅仅在3000-4000年后，随着北半球冰川冰盖的融化，冬季季风风的强度在短短100年的时间里减弱了。(C)1999 Elsevier Science B.V.保留所有权利。
Based on the study of 10 sediment cores and 40 core-top samples from the South China Sea (SCS) we obtained proxy records of past changes in East Asian monsoon climate on millennial to bidecadal time scales over the last 220,000 years. Climate proxies such as global sea level, estimates of paleotemperature, salinity, and nutrients in surface water, ventilation of deep water, paleowind strength, freshwater lids, fluvial and/or eolian sediment supply, and sediment winnowing on the sea floor were derived from planktonic and benthic stable-isotope records, the distribution of siliciclastic grain sizes, planktonic foraminifera species, and the U-37(K) biomarker index. Four cores were AMS-C-14-dated. Two different regimes of monsoon circulation dominated the SCS over the last two glacial cycles, being linked to the minima and maxima of Northern Hemisphere solar insolation. (1) Glacial stages led to a stable estuarine circulation and a strong O-2-minimum layer via a closure of the Borneo sea strait. Strong northeast monsoon and cool surface water occurred during winter, in part fed by an inflow from the north tip of Luzon. In contrast, summer temperatures were as high as during interglacials, hence the seasonality was strong. Low wetness in subtropical South China was opposed to large river input from the emerged Sunda shelf, serving as glacial refuge for tropical forest. (2) Interglacials were marked by a strong inflow of warm water via the Borneo sea strait, intense upwelling southeast of Vietnam and continental wetness in China during summer, weaker northeast monsoon and high sea-surface temperatures during winter, i.e, low seasonality. On top of the long-term variations we found millennial- to centennial-scale cold and dry, warm and humid spells during the Holocene, glacial Terminations I and II, and Stage 3. The spells were coeval with published variations in the Indian monsoon and probably, with the cold Heinrich and warm Dansgaard-Oeschger events recorded in Greenland ice cores, thus suggesting global climatic teleconnections. Holocene oscillations in the runoff from South China centered around periodicities of 775 years, ascribed to subharmonics of the 1500-year cycle in oceanic thermohaline circulation. 102/84-year cycles are tentatively assigned to the Gleissberg period of solar activity. Phase relationships among various monsoon proxies near the onset of Termination IA suggest that summer-monsoon rains and fluvial runoff from South China had already intensified right after the last glacial maximum (LGM) insolation minimum, coeval with the start of Antarctic ice melt prior to the delta(18)O signals of global sea-level rise. Vice versa, the strength of winter-monsoon winds decreased in short centennial steps only 3000-4000 years later, along with the melt of glacial ice sheets in the Northern Hemisphere. (C) 1999 Elsevier Science B.V. All rights reserved.