Collaborative Research: A Polarimetric Radar Climatology of Supercell Thunderstorms in the United States

近年来，龙卷风预警的提前期和误报率并没有显著改善。该合同资助的研究人员将使用升级的气象雷达技术来确定数据中是否存在某些信号，这些信号可以用来帮助提高对龙卷风发展的理解和预测。这项工作的主要社会影响与公共安全有关，通过加强了解和改进数据，帮助业务预报员向公众提供警告。学生还将接受最新方法的培训，以帮助培养高素质的劳动力。2013年，美国国家气象局完成了对国家气象雷达系统双极化能力的升级，从那时起，已经收集了数千次超级单体雷暴的数据。研究小组计划通过开发超级单体雷暴的雷达特征气候学来利用这一资源。该项目的目标是建立极化变量与超级单体特征、结构和进化之间的明确关系。自动化方法将用于选择大约1000个案例，这些案例可用于识别不同极化雷达标记、超级单体演化和近风暴环境参数之间的联系。该项目的具体科学目标是：1)通过识别两组之间的微物理差异来区分龙卷风和非龙卷风超级单体；2)将极化雷达特征和估计的雨滴大小分布与风暴附近环境进行比较；3)确定极化特征和估计的雨滴大小分布在重要风暴过程中是如何变化的。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。

Tornado warning lead times and false alarm rates have not improved significantly in recent years. The researchers funded under this award will use upgraded weather radar technology to determine if there are certain signals in the data that can be used to help improve understanding and forecasting of tornado development. The main societal impact of the work is related to public safety, through enhanced understanding and improved data to help operational forecasters provide warnings to the public. Students will also be trained in the latest methods, helping to provide a highly capable workforce.The National Weather Service completed their upgrade of the nation's weather radar system to dual-polarization capability in 2013, and since that point data has been collected on thousands of supercell thunderstorms. The research team plans to exploit this resource by developing a climatology of radar characteristics of supercell thunderstorms. The goal of the project is to establish definitive relationships between polarimetric variables and supercell characteristics, structure, and evolution. Automated methods will be used to select around 1000 cases that can be used to identify links among distinct polarimetric radar markers, supercell evolution, and near-storm environment parameters. The specific scientific objectives of the project are to: 1) distinguish between tornadic and non-tornadic supercells by identifying microphysical differences between the two sets, 2) compare polarimetric radar signatures and estimated drop size distributions to the near storm environment, and 3) determine how polarimetric signatures and estimated drop size distributions change during important storm processes.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.