末次冰期以来印尼穿越流出口处古海洋学记录及其意义

发布时间：2018-02-24 10:43

  本文关键词： 盐度 西太平洋暖池 厄尔尼诺-南方涛动 北太平洋热带水 印尼穿越流　出处：《海洋地质与第四纪地质》2017年03期 　论文类型：期刊论文

【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。
[Abstract]:The Indonesian current acts as the only way to connect the western Pacific to the Indian Ocean, regulating the exchange of heat and water vapor between the two oceans. In this paper, the Mg/Ca ratios and oxygen isotopes of planktonic foraminifera Globigerinoides ruber and Pulleniatina obliquiloculata shells from the SO18460 borehole at the exit of Indonesia current in the Timor Sea are reanalyzed. The changes of sea water temperature, salinity and thermocline depth since the last glacial period were reconstructed and compared with regional paleoclimate records to study their significance. Since the last glacial period, the salinity of the surface layer and thermocline of Hole so 18460 is consistent with the regional rainfall record. The results show that the rainfall signal is transported from the surface layer to the thermocline layer in the form of salinity of sea water. The temperature of the surface water of the so 18460 hole in the Hole so 18460 has fluctuated at about 28 鈩，

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