Collaborative Research: Reconstructing Holocene Climate Variability and the Indonesian Throughflow in the Western Equatorial Pacific

摘要：根据该奖项，提议者将通过其对太平洋和印度洋的热量和淡水收支以及海气热通量的影响来确定印度尼西亚洋流（ITF）在地球气候中的作用。 将利用沿马卡萨尔海峡300- 700米水深的沿着深度剖面的最佳沉积物岩心中底栖和浮游有孔虫的d18 O和Mg/Ca值，估算盐度和温度。 高积累率将允许重建百年到千年的变化在过去的14,000年。 将处理的具体问题： 赤道西太平洋过去气候变率的关键要素是否与全新世期间ENSO的振幅和频率变化迫使ITF在百年至千年时间尺度上发生变化的假设一致？ ITF全新世突变的时间和幅度与更广泛的热带尺度气候变化的联系是否一致？与热带以外的变化有联系吗？ 在整个全新世ITF强度是否有长期变化？与冰消期ITF的变化相比，这是如何变化的？ 在全新世晚期，明显的向更类似厄尔尼诺的条件的转变或西太平洋暖池的淡化是否影响了ITF？ 淡水化的趋势是否反映了区域对ITCZ向南迁移的反应，或反映了当地季风淡水输入的扩大？该提案的更广泛的影响包括几个研究生和本科生谁将接受与此项目相关的培训，并利用在此项目中生成的数据作为他们的本科或研究生论文的一部分。

Abstract: Under this award the proponents will determine the role of the Indonesian Throughflow (ITF) in Earth's climate through its effect on the heat and freshwater budgets and the air-sea heat fluxes of the Pacific and Indian Oceans. Estimates of salinity and temperature will be generated using d18O and Mg/Ca in benthic and planktonic foraminifera from the best sediment cores along depth transects between 300-700m water depth in the Makassar Strait. High accumulation rates will allow reconstruction centennial to millennial variability over the last ~14,000 years. Specific questions which will addressed: Are key elements of past climate variability in the western equatorial Pacific consistent with the hypothesis that variations in the amplitude and frequency of ENSO force changes in ITF on centennial to millennial time scales during the Holocene? Is the timing and amplitude of Holocene abrupt changes in ITF consistent with a link to broader tropical-scale climate change? Is there a link to extra-tropical changes? Was there a long-term change in ITF strength throughout the Holocene? How does that change compared with the ITF variability during the deglaciation? Did the apparent shift to more El Nino-like conditions in the late Holocene or the freshening of the western Pacific warm pool influence the ITF? Does the freshening trend reflect a regional response to southward migration of the ITCZ or an expansion of local, monsoon-derived freshwater inputs? The proposals broader impacts include several graduate and undergraduate students who will receive training related to this project and utilize data generated in this project as part of their undergraduate or graduate thesis.