Rapid-scan Polarimetric Radar Data Collection and Analysis of the Wind Field in Severe Convective Storms and Tornadoes

该项目的主要目的是使用一种先进的、移动的、快速扫描的多普勒雷达来收集美国平原地区强对流风暴的资料。S.在春季，目的是分析数据，以了解更多关于龙卷风形成的原因以及龙卷风及其母风暴的详细风结构。研究结果可能会改善对强对流风暴及其产生的危害的预测，从而促进公共安全。它还可以帮助结构工程师设计出更能抵御强风的建筑物。该项目还将支持研究生教育;预计学生最终将进入劳动力市场，并通过自己的研究活动或通过操作为社会目标做出贡献。在这个项目中，一个移动的，快速扫描，X波段将部署（3厘米波长）偏振多普勒雷达（RaXPol），以收集超级单元中的体积数据，目的是记录龙卷风的形成和结构，特别是在低海拔地区。比较龙卷风结构的理论模型以及它们如何与自然界中发现的龙卷风演变将增强我们对龙卷风的理解。将以同样的目标分析前几年收集的数据集。特别是，将研究一个数据集，该数据集记录了2021年5月24日堪萨斯西北部一个超级单体中气旋和反气旋龙卷风的起源和演变，包括雷达正在寻找的同步视频。将研究罕见的反气旋龙卷风的详细结构，以确定边界层的风场，因为涡流几乎直接经过雷达。此外，将分析去年在超级单体中收集的现有偏振光谱，并收集更多的数据集，以确定是否能够获得更多关于风暴中水凝物的性质和分布的信息;这些光谱有可能增加我们对冷池产生的理解，已知冷池会影响龙卷风的形成，该奖项反映了NSF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。

The main purpose of this project is to use an advanced, mobile, rapidly-scanning Doppler radar to collect data in severe convective storms in the Plains region of the U. S. during the spring, with the objective of analyzing the data to learn more about why tornadoes form and what the detailed wind structure is of both the tornadoes and their parent storms. The results may lead to improved prediction of severe convective storms and the hazards they produce, thereby promoting public safety. It may also help structural engineers to design buildings more resilient to high winds. This project will also support graduate student education; it is expected that the students will ultimately enter the workforce and contribute to societal goals either through their own research activities or through operations.During this project, a mobile, rapid-scan, X-band (3-cm wavelength) polarimetric Doppler radar (RaXPol) will be deployed to collect volumetric data in supercells, with the objective of documenting tornado formation and structure, especially at low altitudes. Comparing theoretical models of the structure of tornadoes and how they evolve with those found in nature will enhance our understanding of tornadoes. Datasets collected in previous years will be analyzed with the same objectives. In particular, a dataset that documented the genesis and evolution of both a cyclonic and anticyclonic tornado in a supercell in northwestern Kansas on 24 May 2021, including a simultaneous video of where the radar was looking, will be studied. The detailed structure of the rare, anticyclonic tornado will be studied to see determine the wind field in the boundary layer, since the vortex passed almost directly over the radar. In addition, existing polarimetric spectra collected last year in supercells will be analyzed and more datasets collected in an attempt to determine if more information can be obtained about the nature and distribution of hydrometeors within storms; these spectra have the potential for increasing our understanding of the production of cold pools, which is known to affect tornadogenesis, and also increase our understanding of the formation of hail.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.