P2C2: Extratropical Mechanisms, Land-Surface Properties, and Seasonal Precipitation Processes on Saharan Rainfall and Simulation of the African Humid Period

P2C2：撒哈拉降雨的温带机制、地表特性和季节性降水过程以及非洲湿润期的模拟

• 批准号: 1602956
• 负责人: Christopher Poulsen
• 金额: $ 33.1万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-07-01 至 2021-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1602956&HistoricalAwards=false
• 关键词: P2C2; Extratropical; Mechanisms; Land; Surface

This project generally aims to develop an understanding of seasonal non-monsoon processes in order to quantify their contribution to climate change in northern Africa. Specifically, the research aims to provide insights into the relative contributions of the West African Monsoon (WAM), extratropical cyclones, Mediterranean cold air surges, and tropical plumes to African Humid Period (AHP) rainfall (~14,800 - 5,000 years Before Present. At millennial timescales, northern Africa experienced dramatic climate and environmental change. During the early to mid-Holocene AHP, the world's largest present-day hot desert, the Sahara, received abundant rainfall and supported widespread lakes, wetlands, and vegetation. Given the critical role of the present-day Sahara in Earth's radiation budget and its influence on Sahel rainfall, global mineral dust concentrations, biogeochemical cycles, and tropical cyclogenesis, climate variability in the Sahara, such as that observed during the Holocene, has profound impacts on the global climate system. By evaluating the contribution of these processes to AHP rainfall, the research will assist in interpreting the sources of moisture recorded in proxy records from the Sahara-Arabian desert belt which are currently ambiguous because they lie near the border of the tropical monsoon and mid-latitude rainfall regimes. An assessment of the impact of the new dynamic soil albedo scheme within the Community Earth System Model (CESM) will offer tangible insights for climate model development and improved simulation of the AHP. The development of an objective algorithm for the detection of tropical plumes within general circulation models will be made publicly available and could be used to study the processes that influence tropical plume events across the globe in past, present, and future climates.The Broader Impacts involve the potential for increasing the pipeline of underrepresented minority (URM) students into the earth sciences through our participation in the University of Michigan (U-M) Earth Camp. Earth Camp is a residential camp for early-career, high-school students from the Detroit-area that educates them about the earth sciences and careers in the earth sciences. The U-M Earth Camp has consisted of a single summer experience, but is expanding to a multi-summer camp in order to increase the odds that students will study earth sciences in college. As part of our participation in Earth Camp, the participants in this project will develop and instruct a one-day atmospheric science and climate component to the first summer experience in Ann Arbor, MI and create a four-day component for the second summer experience at the U-M field station in Wyoming. In addition to broadening URM participation in the earth sciences, this project will also support the training and career-development of a young scientist and at least one undergraduate student.

该项目总体目标是加深对季节性非季风过程的了解，以量化其对北非气候变化的贡献。 具体来说，该研究旨在深入了解西非季风 (WAM)、温带气旋、地中海冷空气涌和热带羽流对非洲湿润期 (AHP) 降雨（距今约 14,800 - 5,000 年）的相对贡献。千年时间尺度上，北非在全新世早期到中期AHP期间经历了剧烈的气候和环境变化，当今世界上最大的炎热沙漠撒哈拉沙漠经历了丰富的降雨和环境变化。鉴于当今撒哈拉沙漠在地球辐射收支中的关键作用及其对萨赫勒降雨、全球矿物尘浓度、生物地球化学循环和热带气旋发生、撒哈拉气候变化的影响，通过评估这些过程对 AHP 降雨的贡献，该研究将有助于解释撒哈拉-阿拉伯沙漠带代理记录中记录的水分来源。目前尚不清楚，因为它们位于热带季风和中纬度降雨区的边界附近。对社区地球系统模型 (CESM) 中新动态土壤反照率方案影响的评估将为气候模型开发和改进 AHP 模拟提供切实的见解。用于在大气环流模型中检测热带羽流的客观算法的开发将公开，并可用于研究在过去、现在和未来气候中影响全球热带羽流事件的过程。更广泛的影响包括通过参加密歇根大学 (U-M) 地球营，有可能增加代表性不足的少数族裔 (URM) 学生进入地球科学领域的机会。地球营是一个为来自底特律地区的职业生涯早期高中生提供的住宿营，向他们提供有关地球科学和地球科学职业的教育。 密歇根大学地球夏令营由单一夏令营组成，但正在扩展到多个夏令营，以增加学生在大学学习地球科学的机会。作为我们参与地球营的一部分，该项目的参与者将为在密歇根州安娜堡的第一次夏季体验开发和指导为期一天的大气科学和气候部分，并为在密歇根州安娜堡的第二次夏季体验创建为期四天的部分。怀俄明州的密歇根大学野外观测站。除了扩大 URM 在地球科学领域的参与之外，该项目还将支持一名年轻科学家和至少一名本科生的培训和职业发展。