Numerical and Observational Studies of Tornadic Supercells

龙卷风超级单体的数值和观测研究

• 批准号: 9707815
• 负责人: Michael Biggerstaff
• 金额: $ 34.5万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-12-01 至 1999-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9707815&HistoricalAwards=false
• 关键词: Numerical; Observational; Studies; Tornadic; Supercells

9707815 Wicker While progress has been made over the last decade on understanding the dynamics of tornadoes and their parent storms, much is still unknown concerning the factors that cause tornado genesis and that control the intensity and longevity of any given tornado. In this research, the Principal Investigator will investigate how the large scale environment conditions (e.g. wind shear and buoyancy) control the intensity and longevity of tornadoes within supercell thunderstorms. This work builds on and is a logical follow-up to the Principal Investigator's previous research on the development of low-level rotation and tornado genesis within supercell thunderstorms. Two separate lines of research will be pursued. First, the Principal Investigator's current research will be extended down to the tornado scale in an effort to advance understanding of tornadogenesis. The previous work has resulted in refinements to the Rotunno and Klemp paradigm for origins of low-level rotation in supercells. The Principal Investigator s new theory demonstrates the dynamical role the inflow environment's near-surface horizontal vorticity has on mesocyclogenesis and can be used to predict the near-surface vertical wind shear profiles which are optimal for the generation of strong low-level mesocyclones within supercells. Extension of this work includes examining whether tornado-scale circulations are directly related to the mesocyclone circulation, as well as a study to understanding the role of shear and buoyancy in determining the spatial scales and magnitude of the low-level circulation and convergence needed for the generation of tornadoes. Second, an attempt will be made to explicitly model a particular supercell and tornado observed during the Verification of Origins of Rotation in Tornadoes Experiment. This part of the study will provide a much needed evaluation of the current state of cloud simulation realism and hopefully identif y specific aspects of convective scale modeling which need to be improved. Potential benefits from this research are many. Aside from increasing basic understanding of storm and tornado dynamics, the operational community will benefit from this research. Understanding which particular environmental profiles of wind shear, temperature and moisture that are most conducive for tornadoes will enable operational forecasters to pinpoint and focus on small regions where the conditions are favorble for the formation of intense tornadic storms. By more fully understanding the dynamics associated with these supercells and their tornadoes, improved severe weather forecasts and Doppler radar observations can then be used more effectively to forecast and detect tornado formation and warn the public. ***

9707815柳条在过去的十年中取得了进展，在了解龙卷风及其父雨的动态方面，但仍未知导致龙卷风创世纪的因素以及控制任何给定龙卷风的强度和寿命。 在这项研究中，首席研究者将研究大规模环境条件（例如，风剪和浮力）如何控制超级雷暴中龙卷风的强度和寿命。 这项工作是基于主要研究者在超级电池雷暴中发展低级旋转和龙卷风创世纪的发展的先前研究的逻辑后续措施。 将进行两种单独的研究线。 首先，主要研究者的当前研究将扩展到龙卷风量表，以促进对龙卷风发生的理解。先前的工作导致对超级电池中低级旋转起源的Rotunno和Klemp范式进行了改进。主要研究者的新理论表明，流入环境的近表面水平涡度对中周期发生的动态作用，可用于预测近地表垂直风剪切轮廓，该轮廓非常适合产生超级细胞内强的低水平中环龙。 这项工作的扩展包括检查龙卷风尺度的循环是否与中clone循环直接相关，以及研究剪切和浮力在确定龙卷风产生所需的低水位循环和收敛性的空间尺度和幅度中的作用。 其次，将尝试在龙卷风实验中验证旋转起源期间观察到特定的超级细胞和龙卷风。 该研究的这一部分将对云模拟现实主义的当前状态提供急需的评估，并希望确定需要改进的对流量表建模的特定方面。 这项研究的潜在好处很多。 除了对风暴和龙卷风动力学的基本了解日增加外，运营社区还将受益于这项研究。 了解最有利于龙卷风的风剪，温度和水分的特定环境概况将使操作预测者能够查明并专注于对形成强烈龙卷风风暴的条件的小区域。 通过更充分地了解与这些超级电池及其龙卷风相关的动态，可以更有效地使用改善的恶劣天气预测和多普勒雷达观测值，以预测和检测龙卷风形成并警告公众。 ***