Collaborative Research: Quantitative Paleoclimatology of the East African Monsoon

合作研究：东非季风的定量古气候学

• 批准号: 2103001
• 负责人: Emily Beverly
• 金额: $ 13.75万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2103001&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantitative; Paleoclimatology; East

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).The East African Monsoon (EAM) provides intense, seasonal rains that are critically linked to food security and infrastructure for a large portion of global population. The timing and amount of these rains are projected to change substantially under anthropogenic climate change. Studying past intervals of global warmth can inform the scientific community and general public on the direction and magnitude of change in EAM characteristics as the planet warms and cools. This project aims to leverage a large archive of fossil soil (paleosol) samples collected from the Baringo Basin of Kenya, Africa, to reconstruct aspects of past hydroclimate and temperature during the Pliocene-Pleistocene epochs (~4.1-2.6 million years ago). This work will produce the first quantitative estimates of precipitation and temperature across intervals of warming and cooling, including the last time that atmospheric CO2 reached current levels. The response of vegetation to these climate changes will be also be documented, thereby informing the scientific community on the sensitivity of different plant groups to changes in climate parameters. This work will support a large cohort of undergraduate student researchers and a PhD student, and scientific results will be incorporated into upper level, data-driven geoscience courses.Paleosols were previously described in the field in the vicinity of a coring locality associated with the Hominin Sites and Paleolakes Drilling Project. New analyses will include reconstructing paleoclimate (rainfall, temperature) using robust, multivariate models based on paleosol bulk geochemistry as well as the clumped isotope composition of pedogenic carbonates; vegetation will be reconstructed using stable isotopes from pedogenic carbonates and organic matter. This work will provide the first quantitative paleoclimate estimates from the Baringo Basin, which contains the most continuous Neogene stratigraphic record in equatorial eastern Africa and preserves a rich paleontological and paleoanthropological archive. The results of this work will be placed within an existing, high-resolution geochronologic framework to test hypotheses that relate the effect of CO2 rise to EAM strength, local climate seasonality, and landscape-scale vegetation structure. The project will include outcrop-to-core comparisons to evaluate proxy robustness, thereby strengthening paleoclimate and paleoenvironmental interpretations. The multi-proxy approach will allow for rigorous testing of proxy robustness and repeatability.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.

该奖项是根据2021年《美国救援计划法》（公法117-2）全部或部分资助的。东非季风（EAM）提供了与粮食安全和基础设施密切相关的大量季节性降雨，用于大部分全球人口。这些降雨的时间和数量预计将在人为气候变化下发生实质性变化。研究全球温暖的过去间隔可以为科学界和公众提供有关行星温暖和凉爽的EAM特征变化的方向和幅度。该项目旨在利用从非洲肯尼亚的巴林戈盆地收集的大型化石土壤（古）样品，以重建上新世 - 北近代时期的过去氢原气候和温度的各个方面（〜4.1-2600万年前）。这项工作将在温暖和冷却的间隔内产生对降水和温度的第一个定量估计，包括上次大气二氧化碳达到电流水平。还将记录植被对这些气候变化的反应，从而告知科学界不同植物群对气候参数变化的敏感性。这项工作将支持大量的本科生研究人员和一名博士生，科学成果将纳入上层，数据驱动的地球科学课程。先前在与同种蛋白地点和古果质钻探项目相关的Corikity地区的领域中进行了描述。新的分析将包括使用基于古质量的地球化学以及成源性碳酸盐的团块同位素组成的强大的多元模型来重建古气候（降雨，温度）；植被将使用成源性碳酸盐和有机物的稳定同位素重建。这项工作将提供Baringo盆地的首次定量古气候估计值，该盆地包含赤道东非最连续的新金属地层记录，并保留了丰富的古生物学和古人类学档案。这项工作的结果将放置在现有的高分辨率测量框架内，以测试将二氧化碳升高与EAM强度，局部气候季节性和景观规模植被结构相关的假设。该项目将包括露头对核心比较，以评估代理鲁棒性，从而加强古气候和古环境的解释。多种方法的方法将允许对代理鲁棒性和可重复性进行严格的测试。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的知识分子优点和更广泛的影响评估标准通过评估来支持的。