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中更新世气候转型在南海浮游有孔虫、氧同位素和其它生物记录上主要反映在900 ka BP前后发生高频率变化,特别是指示表层水骤然降温。北部冬季表层水温从24~25℃降至17~28℃,而南部也从26~27℃降至23~24℃。总的降温趋势与开放西太平洋一致,直接反映了西太平洋暖池在900 ka BP之后M IS22期间有明显的减弱。表层水大幅度降温还发生在后继的M IS20、18、16几大冰期,说明主要冰期旋回周期由41 ka转变为100 ka经历了长达400 ka的过渡时期,并且冬季风增强也在过渡时期的后半段最明显。南海南北生物组合和1δ8O值的差异,突出了中更新世气候转型期边缘海区南北气候梯度反差和冬季风在冰期增强的讯号。结论是:生态环境系统反应总体表现与冰期旋回一致的同时,还包含了独特的地区性系统演变特征。但是,南海—西太平洋地区在0.9 Ma BP前后表层海水盐度因东亚冬季风和海平面下降的定量变化,以及这些变化对气候转型时期海—气耦合过程和生态环境系统的影响,尚缺乏足够的资料和证据。
The mid-Pleistocene climatic transition mainly reflected the high-frequency changes around planktonic foraminifer, oxygen isotope and other biological records in the South China Sea before and after 900 ka BP, especially the sudden drop of surface water temperature. Surface water temperature in the northern winter dropped from 24-25 ° C to 17-28 ° C while in the south it dropped from 26-27 ° C to 23-24 ° C. The general trend of cooling is consistent with the opening up of the western Pacific, which directly reflects that the western Pacific warm pool significantly weakened during M IS22 after 900 ka BP. The significant cooling of surface water also occurred in the following M IS20,18,16 major ice age, indicating that the main glacial period from 41 ka to 100 ka experienced a transition period of up to 400 ka, and the winter monsoon enhancement is also in the transitional period The second half of the most obvious. Differences in the North-South biological assemblages and 1δ8O values in the South China Sea highlight the contrast between the north-south climate gradients in the marginal seas during the Middle Pleistocene climate change and the increasing winter monsoon during the ice ages. The conclusion is: While the overall ecosystem response is consistent with the glacial cycles, it also contains unique regional system evolutionary characteristics. However, the quantitative changes of surface salinity in the SCS before and after 0.9 Ma BP due to the decline of winter monsoon and sea level in East Asia and the impact of these changes on the sea-atmosphere coupling process and ecosystem during climate transition are still lacking Information and evidence