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

摘要：根据这一奖项，提出者将通过印尼贯穿流(ITF)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它在地球气候中的作用。将使用马卡萨尔海峡300-700米水深范围内最佳沉积岩芯中的底栖和浮游有孔虫中的d18O和镁/钙来估算盐度和温度。较高的累积率将允许在过去约14,000年内重建百年至千年的变化。将讨论的具体问题：赤道西太平洋过去气候变异性的关键要素是否与全新世期间ENSO幅度和频率的变化迫使ITF在百年至千年的时间尺度上发生变化的假设一致？全新世ITF突然变化的时间和幅度是否与更广泛的热带规模气候变化的联系一致？这与热带以外的变化有联系吗？在整个全新世，ITF的实力是否有长期的变化？与冰川消融期间ITF的变化相比，这是如何变化的？在全新世晚期明显转向更类似厄尔尼诺的条件，或者西太平洋暖池的清新是否影响了ITF？淡化趋势是否反映了区域对ITCZ南迁的反应，还是反映了当地季风带来的淡水投入的扩大？提案的更广泛影响包括几名研究生和本科生，他们将接受与该项目有关的培训，并将该项目产生的数据作为其本科生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.