P2C2: Characterizing East African Climate Through a Major Faunal Transition at 250 - 550 ka

自人类起源以来，热带东非的大湖区一直是人类占领和定居的磁石，但目前是世界上最不发达的地区之一。与此同时，该地区未来的气候趋势仍然相对未知。该项目将为马拉维湖盆地未来的水气候提供一个过去的视角，可以将气候模型与之进行比较，以便更可靠地预测降雨和干旱，从而为该区域的水管理提供急需的技术基础。这些结果还将为我们物种和东非其他哺乳动物在其考古和进化史的关键时期的进化提供重要的背景。该项目将通过指导活动支持研究生和本科生，旨在提高未来解决国家环境和社会需求的职业成功的可能性。研究人员将为中学教育工作者提供一个研讨会，带来沉积岩芯的实践经验。研究人员和教育工作者将通过编写经过测试的备课材料，共同开发有关现代环境和气候问题的课程。具体地说，该研究项目将开发关于东非南部过去温度和降雨量的高分辨率记录，该记录跨越了发生在50万到30万年前的一个相对准确的、最近的和重大的进化事件。这项研究将集中在东非南部的马拉维湖盆地，在那里，马拉维湖钻探项目在非洲大陆恢复了迄今最长的高分辨率气候变化记录。研究人员将分析马拉维湖钻探岩芯中的沉积物，分析时间大约为1000年，时间间隔为25万至55万年前，通过沉积物中的有机地球化学信号(TEX86，树叶蜡碳和氢同位素组成)记录下来。这些分析结果将与世界各地的其他类似结果进行比较，以寻求在气候变化的时间或方向上的共性。该团队还将把他们的结果与该地区的气候模型重建进行比较，测试各种气候模型预测非洲气候的准确性，并更好地理解是什么导致了观察到的气候行为。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。

The great lakes region of tropical East Africa has been a magnet for human occupation and settlement since the origin of our species but currently is one of the most underdeveloped in the world. Meanwhile, the future climate trends of the region remain relatively unknown. This project will provide a perspective from the past on the future hydroclimate of the Lake Malawi basin, against which climate models can be compared for more reliable predictions of rainfall and drought and thus offer a much needed technical basis for water management in the region. The results will also provide important context to the evolution of our species and other mammals of eastern Africa during a crucial time period of its archaeological and evolutionary history. The project will support graduate and undergraduate students with mentoring activities designed to improve the likelihood of success in future careers which address national environmental and societal needs. The researchers will offer a workshop to secondary school educators that will bring hands-on experience with sediment cores. The researchers and educators will work together on curriculum development about modern day environmental and climate concerns by creating tested teacher-prep materials.Specifically, the research project will develop a high-resolution record of past temperature and rainfall in southern East Africa that spans a relatively well dated, recent, and significant evolutionary event that occurred sometime between 500 and 300 thousand years ago. The study will focus on the Lake Malawi basin in southern East Africa, where the Lake Malawi Drilling Project recovered the longest, high-resolution record of climate change yet to be recovered from the African continent. Researchers will analyze sediments in the Lake Malawi drill core at roughly a 1000-year interval for temperature and rainfall between 250 and 550 thousand years ago, as recorded by organic geochemical signals in the sediments (TEX86, leaf wax carbon and hydrogen isotopic composition). These analytical results will be compared to other such results from around the world, to seek commonality in the timing or direction of climate change. The team will also compare their results with climate model reconstructions of the region, to test the accuracy of various climate models that hindcast African climate, and to better comprehend what caused the observed climate behavior.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.