Collaborative Research: Quantifying East African hydroclimate seasonal variability for humid intervals during the last 200 kyrs, Omo-Turkana Basin

合作研究：量化东非奥莫-图尔卡纳盆地过去 200 公里潮湿区间水文气候季节性变化

• 批准号: 2123074
• 负责人: Catherine Beck
• 金额: $ 13.23万
• 依托单位: Hamilton College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-15 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2123074&HistoricalAwards=false
• 关键词: Collaborative; Research; Quantifying; East; African

The proposed project will examine the ways in which monsoon variability shapes ecosystems by studying samples from Omo-Turkana in eastern Africa. This project will use a variety of tools to examine seasonal rainfall variability and test whether increased seasonality is strongly correlated with wet intervals. Fossil data and chemical analyses will be used to understand past environments and help determine how this sensitive, water-limited region will respond to a modern and future world shaped by anthropogenic climate change. International collaboration will include training opportunities for the next generation of geoscientists, with a focus on supporting undergraduates from both the US and Ethiopia. Both PIs are based at Primarily Undergraduate Institutions and will develop a learning community through pre-fieldwork programming, collaborative fieldwork, and regular project team meetings. The project has the potential to recruit, engage and retain students from historically underserved communities in STEM to continue as leaders in the geosciences. This project will test the hypothesis that solar insolation maxima increased the strength of the East African monsoon, resulting in enhanced seasonality in eastern Africa during humid periods. Understanding the extremes of seasonality is essential to constrain the terrestrial paleoclimatic and thus paleoenvironmental conditions and resource availability in eastern Africa where early hominins and modern humans evolved. Specifically, the project will 1) establish a single valve ostracod carbon and oxygen isotope proxy record of the eastern African seasonality during wet phases over the last 200 kyrs, 2) develop complementary ostracod-based proxy records of seasonality using trace elements and ostracod-paleoecology, and 3) use modern water isotope records to develop and calibrate a model of paleo-hydroclimate for key intervals over the past 200 kyrs. Given the sensitivity of the study site to significant atmospheric phenomena such as the Intertropical Convergence Zone (ITCZ) and walker circulation, the outcome of this study will improve understanding of the degree of seasonality in humid intervals over the last 200 kyrs.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.

拟议中的项目将通过研究非洲东部奥莫-图尔卡纳地区的样本来检验季风变化对生态系统的影响。该项目将使用各种工具来检查季节性降雨变化，并测试季节性增加是否与湿润间隔密切相关。化石数据和化学分析将用于了解过去的环境，并帮助确定这个敏感的、水资源有限的地区将如何应对由人为气候变化塑造的现代和未来世界。国际合作将包括为下一代地球科学家提供培训机会，重点是支持来自美国和埃塞俄比亚的本科生。这两个pi都以本科院校为主，并将通过实地考察前规划、协作实地考察和定期项目团队会议建立一个学习社区。该项目有潜力从历史上服务不足的STEM社区招募、吸引和留住学生，让他们继续成为地球科学领域的领导者。该项目将检验这样一种假设，即太阳日照最大值增加了东非季风的强度，从而导致东非在潮湿时期的季节性增强。了解极端季节性对于限制非洲东部的陆地古气候以及古环境条件和资源可用性至关重要，非洲东部是早期人类和现代人类进化的地方。具体而言，该项目将1)建立过去200年东非湿润期单气门介形虫碳氧同位素代用记录；2)利用微量元素和介形虫古生态学建立基于介形虫的补充性代用记录；3)利用现代水同位素记录建立和校准过去200年关键时期的古水文气候模型。考虑到研究地点对热带辐合带（ITCZ）和walker环流等重要大气现象的敏感性，本研究的结果将提高对过去200年湿润间隔季节性程度的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。