Studies of Severe Convective Storms and Tornadoes

强对流风暴和龙卷风的研究

• 批准号: 9912097
• 负责人: Howard Bluestein
• 金额: $ 48.91万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9912097&HistoricalAwards=false
• 关键词: Studies; Severe; Convective; Storms; Tornadoes

The goal of this research project is to understand better the dynamics of severe convective storms and tornadoes. This goal will be met through the analysis of observational data sets and from idealized numerical simulation experiments.Mobile Doppler radar data sets collected in tornadoes will be analyzed in detail and a small, focussed field experiment will be conducted to collect and analyze additional data in order to obtain a better statistical characterization of tornadoes and their environment. The main thrust of this effort will be to estimate wind speeds near the ground in tornadoes, determine the three-dimensional wind field in tornadoes, determine why tornadoes form and dissipate and find out why some supercell storms produce tornadoes, while others do not.Numerical simulation experiments will be conducted in order to understand the dynamics of an elevated rear-inflow jet and a counterrotating vortex couplet observed in an airborne Doppler radar analyses of a nontornadic supercell hailstorm. It is hypothesized that the vortex couplet was created through the tilting of horizontal vorticity by the downdraft in the storm. The importance of this study is that the rear-inflow jet and vortex couplet may be characteristic of a subclass of supercell storms.Successful completion of this research will lead to better conceptual models of tornadoes and tornado genesis and eventually lead to more accurate predictions.

该研究项目的目标是更好地了解强对流风暴和龙卷风的动力学。 这一目标将通过分析观测数据集和理想化的数值模拟实验来实现，将详细分析在龙卷风中收集的移动的多普勒雷达数据集，并将进行一个小型的、有重点的实地实验，以收集和分析更多的数据，以便更好地统计龙卷风及其环境的特征。 这项工作的主要目标是估计龙卷风中接近地面的风速，确定龙卷风中的三维风场，确定龙卷风形成和消散的原因，并找出一些超级单体风暴产生龙卷风的原因，为了了解高架后桥的动力学特性，将进行数值模拟实验，在非龙卷风超级单体雹暴机载多普勒雷达分析中观测到的入流喷流和反向旋转涡对。 据推测，涡偶是由风暴中的下沉气流使水平涡度倾斜而产生的。 这项研究的重要性在于，后入流射流和涡偶可能是超级单体风暴的一个子类的特征。这项研究的成功完成将导致更好的龙卷风和龙卷风成因的概念模型，并最终导致更准确的预测。