A one-million record of orbital-scale changes in temperature and precipitation from the Indo-Pacific Warm Pool

热带气候正在迅速变化--降雨事件变得更加强烈，干旱变得更加严重。这些变化影响了气候变化，影响了数十亿依赖降雨谋生的人的生活，并由于热带气候与全球气候之间的联系，对世界产生了重要影响。预测未来的降雨量和气温将如何变化需要长时间的记录来检验气候模型和理论。这种记录在热带地区一般很少，特别是在热带西太平洋，那里现有的记录在过去气候变化的模式和规模上存在很大分歧。该项目的目标是开发热带西太平洋地区的温度、降雨量和植被的新记录，并调查其原因。热带西太平洋地区对全球气候过程特别重要。这项研究将使我们能够检验热带和全球气候变化的理论，从而改进对该地区未来气候的预测。该项目将为美国研究生和本科生提供许多进行研究的机会，并将开发新的气候变化课堂模块，用于普罗维登斯公立学校系统。这项研究将通过分析最近从印度尼西亚中部苏拉威西岛上的托武蒂湖采集的沉积物钻芯，调查过去110万年来印度-太平洋暖池(IPWP)的降雨量、温度和植被的轨道尺度变化。通过对这些沉积物的有机地球化学分析，该项目将评估热带季节日照、高纬度冰量、温度、大气温室气体浓度和海平面的变化在全球气候边界条件的关键转变期间对IPWP气候的影响。这项研究将侧重于80万年前的中更新世期间的全球气候过渡，当时冰川-间冰期的变化从主要的41 KYR周期过渡到100 KYR冰期周期，以及43万年后100 KYR周期的加剧。这一结果有望有助于理解热带气候如何随着气候边界条件的不同而变化。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Tropical climate is changing rapidly – rainfall events are becoming more intense, and droughts more severe. These changes affect the affect the lives of billions of people who rely on rainfall for their livelihoods, and have important implications for the world due to connections between tropical and global climates. Predicting how rainfall and temperature will change in the future requires long records to test climate models and theory. Such records are generally scarce in the tropics, and particularly in the tropical western Pacific, where existing records disagree substantially on the pattern and magnitude of past changes in climate. The goal of this project is to develop new records of temperature, rainfall, and vegetation from the tropical western Pacific, a region that is especially important to global climate processes, and to investigate their causes. This research will enable us to test theories of tropical and global climate change, and thereby to improve the prediction of future climates in this region. The project will provide for many opportunities for US graduate and undergraduate students to conduct research and will develop new classroom modules on climate change to be used in the Providence Public School System.This research will investigate orbital-scale variations in rainfall, temperature, and vegetation during the past 1.1 million years in the Indo-Pacific Warm Pool (IPWP) through analysis of recently-recovered sediment drill cores from Lake Towuti, located on Sulawesi Island in central Indonesia. Through organic geochemical analyses of these sediments, the project will evaluate the impacts of changes in tropical seasonal insolation, high-latitude ice volume, temperature, and atmospheric greenhouse gas concentrations, and sea level on IPWP climate across critical transitions in global climate boundary conditions. The research will focus on global climate transitions during the Mid-Pleistocene, 800,000 years ago, when glacial-interglacial variability transitioned from predominantly 41-kyr to 100-kyr ice-age cycles, and 430,000, when the 100-kyr cycles intensified. The results are expected to contribute to understanding how tropical climates change in response to climate boundary conditions that differ from the present day.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.