Collaborative Research: P2C2--East African Monsoon Hydroclimate over the Last 11,500 Years

合作研究：P2C2——过去11,500年的东非季风水文气候

• 批准号: 2002446
• 负责人: Kim Cobb
• 金额: $ 5.49万
• 依托单位: Georgia Tech Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2002446&HistoricalAwards=false
• 关键词: Collaborative; Research; P2C2; East; African

This project aims to build proxy records of speleothem stable isotopes to discern decadal to centennial scale variability in eastern African hydroclimate. The study site is sensitive to large- scale features of the global atmospheric circulation (El nino Southern Oscillation, Walker circulation, monsoon system) and new hydroclimate records will improve the understanding of the drivers of decadal to millennial hydroclimate change in this key region and beyond. Specifically, the researchers will: 1) Establish a high–resolution multi-cave geochronology using extensive Uranium-Thorium (U-Th) dating to determine the duration and magnitude of hydroclimate changes in East Africa. These high-resolution dates will allow identification of active growth intervals vs dry intervals as expressed across the network of caves; 2) Characterize the role of different processes (e.g. large-scale atmospheric circulations and convective processes, local land-atmospheric processes such as re-evaporation etc, and karst hydrological processes such as mixing, recharge) on modern rainwater and dripwater oxygen stable isotopes via the monitoring of cave modern hydrology, analysis of instrumental climate data, and isotope-enabled climate model output; 3) Carry out high-resolution reconstructions of relatively short intervals at ~ 9000 years that are shared across several stalagmites as identified through the U-Th dating targeting. The potential Broader Impacts include generating a detailed knowledge of the nature, timing, and local/regional extent of climatic and environmental changes in Eastern Africa over the last 11,500 years and links to large- scale features of the global atmospheric circulation. The project will provide training for undergraduate and graduate students and will contribute to training of next generation climate scientists particularly from underrepresented groups. Focus will be on cross training in analytical techniques, data analysis, and modeling. This project will facilitate knowledge-based international cooperation with Ethiopian universities.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.

该项目旨在建立洞穴稳定同位素的代用记录，以辨别东非水文气候的年代际到百年尺度变化。研究地点对全球大气环流（厄尔尼诺-南方涛动、沃克环流、季风系统）的大尺度特征敏感，新的水文气候记录将提高对该关键地区及以后年代际至千年水文气候变化驱动因素的认识。具体来说，研究人员将：1)建立一个高分辨率的多洞穴地质年代学，使用广泛的铀钍（U-Th）测年来确定东非水文气候变化的持续时间和幅度。这些高分辨率的日期将使我们能够通过洞穴网络来确定活跃的生长间隔和干燥的生长间隔；2)通过洞穴现代水文监测、仪器气候数据分析和同位素支持气候模式输出，表征不同过程(如大尺度大气环流和对流过程、局部陆地-大气过程（如再蒸发等）和喀斯特水文过程（如混合、补给）对现代雨水和滴水氧稳定同位素的作用；3)通过U-Th测年目标确定的几个石笋，在~ 9000年的相对短间隔内进行高分辨率重建。潜在的更广泛的影响包括产生关于过去11500年来东非气候和环境变化的性质、时间和局部/区域范围的详细知识，以及与全球大气环流大尺度特征的联系。该项目将为本科生和研究生提供培训，并将有助于培养下一代气候科学家，特别是来自代表性不足群体的气候科学家。重点将放在分析技术、数据分析和建模的交叉培训上。该项目将促进与埃塞俄比亚大学之间基于知识的国际合作。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。