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

摘要：在这个奖项下，倡议者将通过印度尼西亚通流（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。将利用在望加锡海峡300-700米水深之间的最佳沉积物岩心中底栖生物和浮游有孔虫中的d18O和Mg/Ca来估算盐度和温度。高积累率将允许重建过去~ 14000年的百年至千年变率。将解决的具体问题：赤道西太平洋过去气候变率的关键因素是否与全新世期间ENSO强迫ITF在百年至千年时间尺度上的振幅和频率变化的假设相一致？全新世ITF突变的时间和幅度是否与更广泛的热带尺度气候变化相一致？这与热带外的变化有联系吗？在整个全新世中，是否有ITF强度的长期变化？与冰川消融期间的ITF变率相比，这是如何变化的？是全新世晚期明显转向更像厄尔尼诺的条件，还是西太平洋暖池的变暖影响了ITF？淡水变新鲜的趋势是否反映了区域对ITCZ向南迁移的响应，还是当地季风产生的淡水输入的扩大？该提案的广泛影响包括一些研究生和本科生，他们将接受与该项目相关的培训，并利用该项目产生的数据作为其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.