Using the Second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) Observations and Idealized Simulations to Understand the Lifecycle of Tornadoes

在为期两年的多调查员实地数据收集活动取得成功之后，这项研究工作将侧重于确定对龙卷风的发生、维持和消亡至关重要的物理过程和相互作用，这些龙卷风在更广泛的旋转流（“中气旋”）中发展，是超级单体雷暴的特征。 需要更好地理解和开发更可靠的方法来识别龙卷风的形成并提供预警，这是NSF-NOAA联合赞助的VORTEX 2（龙卷风旋转起源的验证）项目的关键目标，该项目包括多平台现场活动，提供了大量的雷达和现场热力学数据，包括严重的雷暴，龙卷风及其支持环境。 这项工作的智力价值将取决于该研究小组的具体计划，以利用这些数据来研究龙卷风的发生，维持和消亡的控制，以及风暴合并在影响这些过程中的潜在作用。 基于模型的数据分析和同化将与更理想化的数值模拟方法同时进行。 在本项目期间要解决的具体研究目标是：（1）确定环境与风暴产生的涡度在龙卷风的发生和演变中的相对作用（2）研究后翼和前翼下沉气流在龙卷风的发生和演变中的作用，（3）研究次级后翼阵风锋的起源和特征，以及它们在龙卷风发生和演变中的可能作用，（4）探讨龙卷风如何受到中气旋尺度环境的热力学性质和环流变化以及上层雷暴上升气流的强度或位置变化的影响，以及（5）研究风暴相互作用和单体合并的动力学，以及它们如何影响风暴中涡度的发展。这项工作的更广泛影响将取决于物理理解的转移，（c）向业务气象学家提供潜在的分析技术，以便他们最终可以提供更准确的龙卷风警报，降低误报率，并为培训学生和早期职业科学家，包括来自大气科学领域代表性不足群体的个人提供机会。

Following on a successful two-year multi-investigator field data collection campaign, this research effort will focus on identification of physical processes and interactions pivotal to the genesis, maintenance, and demise of tornadoes developing within broader rotational flows ("mesocyclones") that characterize supercell thunderstorms. The need for improved understanding and development of more reliable means to identify and provide advance warning of tornado formation are key objectives of the joint NSF-NOAA sponsored VORTEX2 (Verification of the Origins of Rotation in Tornadoes) project, which encompassed multi-platform field activities providing a wealth of radar and in-situ thermodynamic data within severe thunderstorms, tornadoes, and their supporting environments. The intellectual merit of this effort will rest upon this research team's specific plans to exploit these data in their study of controls on tornado genesis, maintenance and demise, as well as the potential role of storm mergers in influencing these processes. Model-based data analysis and assimilation will be conducted in tandem with more idealized numerical simulation approaches. The specific research objectives to be addressed during this project are to: (1) Determine the relative roles of environmental versus storm-generated vorticity in the genesis and evolution of tornadoes (2) investigate the roles of the rear- and forward-flank downdrafts in the genesis and evolution of tornadoes, (3) examine the origin and characteristics of secondary rear-flank gust fronts and their possible role in the genesis and evolution of tornadoes, (4) explore how tornadoes are influenced by changes in the thermodynamic properties and circulation of their mesocyclone-scale surroundings, and by changes in the strength or location of the overlying parent thunderstorm updraft, and (5) to investigate the dynamics of storm interactions and cell mergers and the ways in which they can influence the development of vorticity in the storms.Broader impacts of this effort will hinge upon transfer of physical understanding and potential analysis techniques to operational meteorologists in order that they may ultimately provide more precise tornado warnings and decreased false alarm rates, as well as in providing the opportunity for training of students and early-career scientists including individuals drawn from underrepresented groups in the atmospheric sciences.