Variability in Indonesian Throughflow Upper Hydrology in Response to Precession‐Induced Tropical Climate Processes Over the Past 120 kyr
Variability in Indonesian Throughflow Upper Hydrology in Response to Precession‐Induced Tropical Climate Processes Over the Past 120 kyr
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DOI：
10.1029/2020jc017014
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发表时间：
2021-08
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影响因子：
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通讯作者：
Peng Zhang;Jian Xu;S. Beil;A. Holbourn;W. Kuhnt;Tiegang Li;Z. Xiong;Hong Yan;Rui Cui
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作者：
Peng Zhang;Jian Xu;S. Beil;A. Holbourn;W. Kuhnt;Tiegang Li;Z. Xiong;Hong Yan;Rui Cui
印度尼西亚贯通流(ITF)作为连接太平洋和印度洋的唯一低纬通道，调节着这两个海洋之间的温盐平衡。因此，研究ITF的变率及其与岁差强迫的关系对于理解热带气候变化的驱动因素是至关重要的。在这里，我们重建了过去的∼120KYR的历史，基于高分辨率(∼4000年)δ18O和从位于ITF主要通道内的弗洛里斯海上升流区的SO217-18540孔中提取的Globigerinoides ruberus和Pulleniatina obliquiloculata的镁/钙记录。将这些新记录与热带太平洋西部公布的古海洋学和气候学数据进行比较，表明弗洛雷斯海的年平均状况是由ITF变率控制的，而不是由季风上升流控制的。我们的结果进一步表明，岁差日照是过去120个KYR期间ITF水文演变的主要驱动力。我们认为，岁差强迫通过调节类厄尔尼诺-南方涛动条件的平均状态和热带辐合带的纬向移动和/或扩张/收缩来控制ITF的变率。
The Indonesian Throughflow (ITF), as the sole low‐latitude conduit connecting the Pacific and Indian Oceans, regulates the thermohaline balance between these oceans. Thus, investigating the variability in the ITF and its relationship with the precessional forcing is crucial for understanding the drivers of tropical climate change. Here, we reconstruct the history of the ITF over the past ∼120 kyr based on high‐resolution (∼400 years) δ18O and Mg/Ca records ofGlobigerinoides ruberandPulleniatina obliquiloculatafrom core SO217‐18540 retrieved from the Flores Sea upwelling region within the main pathway of the ITF. A comparison of these new records with published paleo‐oceanographic and climatological data from the western tropical Pacific Ocean suggests that annual mean conditions in the Flores Sea were controlled by ITF variability rather than by monsoonal upwelling. Our results further indicate that precessional insolation was a major forcing for the hydrological evolution of the ITF during the past 120 kyr. We suggest that the precessional insolation forcing paced ITF variability by modulating the mean state of El Niño‐Southern Oscillation‐like conditions and latitudinal shifts and/or expansion/contraction of the Intertropical Convergence Zone.