Collaborative Research: A 650,000 year record of hydroclimate in the Western Pacific Warm Pool: Scientific Drilling at Lake Towuti, Indonesia

本研究将重建印度尼西亚中部过去65万年的气候和环境变化。为了实现这一目标，项目科学家将从托乌提湖底钻取长长的沉积物岩心。托乌提湖是印度尼西亚苏拉威西岛上的一个大湖，它包含了东南亚已知最长的陆地气候记录。这些岩心将被分析其物理、化学和生物特性，以推断热带太平洋地区中心地区过去的降雨量变化。这些数据将用于评估区域降雨对轨道周期、温室气体变化和全球冰期-间冰期周期变化的响应。热带西太平洋是全球气候系统中极其重要的一部分，但人们对其对全球气候强迫和变化的反应知之甚少。这项工作将为研究控制印尼气候变化的基本过程提供最长的连续气候记录。该研究小组将与来自印度尼西亚、德国、瑞士、加拿大和澳大利亚的科学家合作开展该项目，为学生和教师提供跨学科和国际研究培训机会。该项目将有助于开发新的博物馆展示，并将通过网络直播活动吸引公众。图乌提湖是东南亚最大的构造湖，是国际大陆科学钻探计划（ICDP）的优先古气候目标。地震反射和浅层沉积物岩心表明，图乌提湖包含一段100-200 m厚的分层湖泊沉积物，该沉积物连续跨越了过去~65万年BP，是东南亚已知最长的陆相沉积物。这项研究由布朗大学、罗德岛大学和明尼苏达大学的科学家合作进行，将研究热带西太平洋气候对更新世晚期轨道强迫和全球气候边界条件变化的反应。这项研究是多国在图乌提湖钻探项目的一部分。该奖项为钻探提供资金，为岩心开发年龄模型，并根据一系列沉积学、地球化学和有机地球化学测量结果生成过去~65万年的气候代理重建。知识价值：热带西太平洋水文的变化对全球大气环流和大气水蒸气（最丰富的温室气体）的浓度产生巨大影响。尽管它很重要，但西太平洋水文对全球气候的反应仍然高度不确定。该团队将收集和开发该地区最长的连续气候记录，并将该记录与低纬度和高纬度海洋和陆地站点的重建记录进行比较，以了解热带太平洋水文气候对过去65万年中轨道强迫和全球气候边界条件变化的响应。更广泛的影响：这项工作将为控制热带水文长期变化的机制提供重要的见解，并将为古气候模式提供一个基准测试平台，以模拟不同边界条件下的气候。该项目将为美国和印度尼西亚的学生和科学家提供跨学科的国际研究培训和学习机会。这项工作将有助于发展新的博物馆展览，并将通过网络推广活动与该领域的科学家进行互动。迄今为止，这项研究在印度尼西亚产生了相当大的宣传和当地教育机会，包括在国家电视台播出纪录片节目。团队将在整个项目中继续这些活动。

NON-TECHNICAL ABSTRACTThis research will reconstruct the past climatic and environmental change in central Indonesia over the last 650,000 years. To accomplish this goal, project scientists will drill long sediment cores from the bottom of Lake Towuti, a large lake on the island of Sulawesi, Indonesia, which contains the longest known record of terrestrial climate from anywhere in southeast Asia. These cores will be analyzed for their physical, chemical, and biological properties to deduce past variations in rainfall in the heart of the tropical Pacific region. These data will be used to assess the response of regional rainfall to changes in orbital cycles, greenhouse-gas variations, and global glacial-interglacial cycles.The tropical western Pacific is an extremely important part of the global climate system, yet its response to global climate forcings and change remains poorly understood. This work will provide the longest continuous record of climate available to investigate the fundamental processes that control Indonesian climate variations. The research team will collaborate with scientists from Indonesia, Germany, Switzerland, Canada, and Australia on this project, stimulating interdisciplinary and international research training opportunities for students and teachers. The project will contribute to developing new museum displays and will engage the public via live web outreach activities.TECHNICAL ABSTRACTLake Towuti is the largest tectonic lake in Southeast Asia and is a high priority paleoclimate target within the International Continental Scientific Drilling Program (ICDP). Seismic reflection and shallow sediment cores indicate that Lake Towuti contains a 100-200 m thick section of stratified lacustrine sediment that continuously spans the last ~650,000 years BP, the longest known terrestrial section in Southeast Asia. This research--a collaboration between scientists from Brown University, the University of Rhode Island, and the University of Minnesota--will investigate the response of tropical western Pacific climate to changes in orbital forcing and global climate boundary conditions through the late Pleistocene. The research is part of a multinational drilling program on Lake Towuti. This award provides funding to drill, to develop age models for the cores, and generate climate proxy reconstructions of the past ~650,000 years based upon a suite sedimentological, geochemical, and organic geochemical measurements.Intellectual Merit: Changes in tropical western Pacific hydrology exert enormous influence on global atmospheric circulation and on the concentration of atmospheric water vapor, the most abundant greenhouse gas. Despite its importance, the response of western Pacific hydrology to global climate remains highly uncertain. The team will collect and develop the longest continuous record of climate available from this region and compare this record with reconstructions from low and high-latitude marine and terrestrial sites to understand the response of tropical Pacific hydroclimate to changes in orbital forcing and global climate boundary conditions during the last 650,000 years.Broader Impacts: This work will provide important insight into the mechanisms governing long-term change in tropical hydrology and will provide a benchmark test-bed for paleoclimate models to simulate climate under different boundary conditions than the present. This project will provide interdisciplinary, international research training and learning opportunities to US and Indonesian students and scientists. This work will contribute to the development of new museum displays, and will engage the public with scientists in the field via interactions through web outreach activities. The research to date generated considerable publicity and local educational opportunities within Indonesia, including documentary programs on national television. The team will continue these activities throughout this project.