Collaborative Research: Supercell Left Flank Boundaries and Coherent Structures--Targeted Observations by Radars and UAS of Supercells Left-flank-Intensive Experiment (TORUS-LItE)

合作研究：超级单元左翼边界和相干结构——雷达和无人机对超级单元左翼密集实验（TORUS-LItE）的定向观测

• 批准号: 2312994
• 负责人: Adam Houston
• 金额: $ 38.51万
• 依托单位: University of Nebraska-Lincoln
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2312994&HistoricalAwards=false
• 关键词: Collaborative; Research; Supercell; Left; Flank

Supercell thunderstorms are responsible for the majority of significant tornadoes in the United States. However, not all supercells form tornadoes and the false alarm rate for tornado warnings is stubbornly high. This small field campaign will use a variety of instrumentation, including radar trucks and uncrewed aerial systems (UAS) to observe atmospheric boundaries that form in what is known as the left flank region of a supercell. The idea is that observing small scale motions and boundaries near supercells will allow us to better understand why some supercells form tornadoes while others do not. Beyond the practical operational forecasting aspect of this project, the field campaign will provide 15-20 students with the opportunity to participate in the collection of data. This award is for the Targeted Observations by Radars and UAS of Supercells Left-flank-Intensive Experiment (TORUS-LItE), an observational study of specific processes in the left flank of supercell thunderstorms and how they relate to tornadogenesis. The research team will deploy UAS, radar, sounding, and mobile Mesonet assets during a three-week period in May and June 2023 in the Great Plains to directly sample boundaries and coherent structures. The investigators believe that advancing understanding of the relationship between supercell tornadogenesis and left/forward flank boundaries and coherent structures requires cross-sectional datasets that enable characterization of the structure and evolution of these boundaries and associated coherent structures in the context of supercell/mesocyclone strength and proximate evolution of near-surface rotation. The science questions to be studied are: A) How often are left/forward-flank boundaries coincident with enhanced vorticity and how does the magnitude of this vorticity relate to the characteristics of the associated boundaries and environmental/ambient state? B) Do the characteristics of streamwise vorticity currents (SVCs) and associated boundaries attendant to tornadic storms differ significantly from those associated with non-tornadic storms? C) Can the dense-side airmasses of left-flank boundaries be characterized as density currents and are SVCs the attendant Kelvin-Helmholtz (KH) billows?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.

超级单体雷暴是造成美国大部分重大龙卷风的原因。 然而，并不是所有的超级单体都会形成龙卷风，龙卷风警报的误报率很高。 这个小型的实地活动将使用各种仪器，包括雷达卡车和无人机系统（UAS），以观察在所谓的超级单体左翼区域形成的大气边界。 其想法是，观察超级单体附近的小规模运动和边界将使我们能够更好地理解为什么一些超级单体形成龙卷风，而另一些则不会。 除了该项目的实际业务预测方面，实地活动将为15-20名学生提供参与收集数据的机会。 该奖项是针对雷达和UAS对超级单体左翼密集实验（TORUS-LITE）的有针对性的观测，这是对超级单体雷暴左翼特定过程及其与龙卷风发生的关系的观测研究。 该研究团队将在2023年5月和6月的三周内在大平原部署UAS，雷达，探空和移动的Mesonet资产，以直接对边界和相干结构进行采样。 研究人员认为，要进一步了解超级单体龙卷风发生与左/前侧翼边界和相干结构之间的关系，需要横截面数据集，以便在超级单体/中气旋强度和近地面旋转的近距离演变的背景下表征这些边界和相关相干结构的结构和演变。 要研究的科学问题是：A）左/前翼边界与增强的涡度重合的频率有多高，这种涡度的大小与相关边界和环境/周围状态的特征有何关系？ B）龙卷风暴所伴随的流向涡度流（SVC）和相关边界的特征与非龙卷风暴所伴随的特征是否有显著的不同？ C）左翼边界的稠密侧气团能否被表征为密度流，SVC是伴随的开尔文-亥姆霍兹（KH）波涛吗？该奖项反映了NSF的法定使命，并被认为是值得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的支持。