中文摘要：

印尼穿越流作为连接西太平洋和印度洋的唯一通道,调节着这两个大洋之间的热量和水汽的交换,继而在热带乃至全球气候变化中扮演着重要的角色。本文对来自于帝汶海内印尼穿越流出口处SO18460钻孔中浮游有孔虫Globigerinoides ruber和Pulleniatina obliquiloculata壳体的Mg/Ca比值和氧同位素进行再分析,重建了末次冰期以来表层和温跃层海水温度、盐度以及温跃层深度的变化,并将其与区域古气候记录对比以探讨其意义。结果表明,末次冰期以来,SO18460孔的表层和温跃层海水盐度均与区域降雨量记录变化一致,显示降雨信号以海水盐度的形式通过水体混合由表层向温跃层的传输。自早全新世以来,SO18460孔的表层海水温度在28℃左右波动,可能是受西太平洋暖池的影响;同时,温跃层海水温度始终低于22℃可能指示厄尔尼诺-南方涛动处于类厄尔尼诺状态;而温跃层海水温度持续下降、温跃层深度持续变浅,一方面可能是对早全新世以来类厄尔尼诺事件频发的响应,另一方面也可能归因于热带辐合带的南向移动导致区域降雨增加、以及东亚冬季风驱使南海表层流的加强等因素对印尼穿越流表层流的抑制。冰期-间冰期尺度上,SO18460孔温跃层海水温度与北半球夏季太阳辐射量变化步幅一致,可能是北太平洋热带水借助棉兰老岛流在苏拉威西海混入印尼穿越流所致。

英文摘要：

The Indonesian Throughflow （ITF）, sole conduit between the Pacific and Indian Oceans, plays an important role in regulating heat and fresh water budgets between the two oceans, and in controlling the tropical and global climate. In this study, we investigated records from the Core SO18460 that was drilled at the exit of the ITF into the Timor Sea to reexamine their significance in reflecting the ITF since the last glacial. Records of temperature and salinity of surface and subsurface seawaters, and depth of thermocline （DOT） were reconstructed from 3180 and Mg/Ca ratio of the planktonic foraminifera of Globigerinoides tuber and Pulleniatina obliquiloculata and were then compared with regional paleoclimatic indices. The results show that salinity of both surface and thermocline seawaters covaried with regional precipitation over the last glacial cycle, likely indicating transmission of precipitation signal by means of seawater salinity from sea surface to thermocline through upper ocean mixing. Sea surface temperature at the coring site of Core SO18460 oscillated centering at 28 ℃, possibly under influence of the Western Pacific Warm Pool since the early Holocene. In contrast, thermcoline seawater temperature （TWT） was always below 22 ℃, probably indicating that E1 Nifio-Southern Oscillation was located in E1 Nifio-like episodes. Decline of TWT and shoal of DOT might be, on the one hand, in response to more frequent E1 Niflo-like events; and on the other hand, resulted from depression of ITF surface flow caused by increased precipitation due to southward shift of the Intertropical Convergence Zone, and/or by intensification of South China Sea surface flow driven by enhanced East Asian winter monsoon during Holocene. On glacial-interglacial times- cale, TWT co-varied with the boreal summer insolation, possibly due to influence of North Pacific Tropical Water sourced waters that were carried by the Mindanao Current to the Sulawesi Sea and merged into the ITF.