Paleoclimate investiations on sediment core MD01-2378

We present a high-resolution (not, vert, similar 60-110 yr) multi-proxy record spanning Marine Isotope Stage 3 from IMAGES Core MD01-2378 (13°04.95'S and 121°47.27'E, 1783 m water depth), located in the Timor Sea, off NW Australia. Today, this area is influenced by the Intertropical Convergence Zone, which drives monsoonal winds during austral summer and by the main outflow of the Indonesian Throughflow, which represents a key component of the global thermohaline circulation system. Thus, this core is ideally situated to monitor the linkages between tropical and high latitude climate variability. Benthic d18O data (Planulina wuellerstorfi) clearly reflect Antarctic warm events (A1-A4) as recorded by the EPICA Byrd and Dronning Maud Land ice cores. This southern high latitude signal is transferred by deep and intermediate water masses flowing northward from the Southern Ocean into the Indian Ocean. Planktonic d18O shows closer affinity to northern high latitudes planktonic and ice core records, although only the longer-lasting Dansgaard-Oeschger warm events, 8, 12, 14, and 16-17 are clearly expressed in our record. This northern high latitude signal in the surface water is probably transmitted through atmospheric teleconnections and coupling of the Asian-Australian monsoon systems. Benthic foraminiferal census counts suggest a coupling of Antarctic cooling with carbon flux patterns in the Timor Sea. We relate increasing abundances of carbon-flux sensitive species at 38-45 ka to the northeastward migration of the West Australian Current frontal area. This water mass reorganization is also supported by concurrent decreases in Mg/Ca and planktonic d18O values (Globigerinoides ruber white).本研究报道了一套高分辨率（约60~110年）的多代用指标记录，其时间跨度覆盖海洋同位素阶段3（Marine Isotope Stage 3），取自位于澳大利亚西北海域帝汶海的IMAGES岩芯MD01-2378（地理坐标：13°04.95'S，121°47.27'E，水深1783米）。现今，该区域受热带辐合带（Intertropical Convergence Zone）影响——该系统在南半球夏季驱动季风环流，同时受印尼贯穿流（Indonesian Throughflow）的主要流出影响；而印尼贯穿流是全球温盐环流系统的关键组成部分。因此，该岩芯所处位置非常适宜监测热带与高纬度气候变率之间的关联。底栖有孔虫δ18O数据（以武氏卷包虫Planulina wuellerstorfi为研究种）清晰记录了南极暖事件（Antarctic warm events，A1~A4），这一信号与EPICA伯德站及毛德皇后地冰芯所记录的结果一致。这种南极高纬度信号通过从南大洋向北流动的深层与中层水团，被输送至印度洋。浮游有孔虫δ18O则更接近北极高纬度的浮游有孔虫与冰芯记录，不过本记录中仅清晰呈现了持续时间较长的丹斯果-奥什格尔暖事件8、12、14以及16~17号事件。表层水中的这一北极高纬度信号，可能通过大气遥相关以及亚澳季风系统的耦合作用得以传递。底栖有孔虫群落计数结果显示，帝汶海的南极降温过程与碳通量格局存在耦合关系。我们将38~45 ka时段内对碳通量敏感的有孔虫类群丰度上升，归因于西澳大利亚流（West Australian Current）锋区向东北方向的迁移。这一水团重组现象，也得到了同期镁钙比（Mg/Ca）与浮游有孔虫δ18O值（以白色红拟抱球虫Globigerinoides ruber white为研究种）下降的佐证。