Microphysical and Kinematic Storm Properties Affecting Electrification and Lightning Production

影响电气化和闪电产生的微物理和运动风暴特性

• 批准号: 0924621
• 负责人: Donald MacGorman
• 金额: $ 52.16万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0924621&HistoricalAwards=false
• 关键词: Microphysical; Kinematic; Storm; Properties; Affecting

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."Intellectual Merit: Under this award the Principal Investigator (PI) will continue investigating how microphysics and kinematics affect storm electrification and lightning production by using lightning mapping, electric field, radar, and other storm observations acquired in Oklahoma since 2003. The Oklahoma Lightning Mapping Array, the local National Weather Service 11-cm polarimetric radar, and a rapid-scanning 10 cm phased array radar have operated for several years. During the Thunderstorm Electrification and Lightning Experiment (TELEX) 2003 and 2004 and on other occasions since then, additional observations, including in situ storm soundings of the electric field, environmental soundings, and mobile 5-cm wavelength dual Doppler radar data, also were collected for select cases. These cases include various types of mesoscale convective systems (MCSs), supercell storms, and other isolated storms. The PI will focus analysis on two broad topics: 1. Analyze the microphysical and kinematic conditions inferred from polarimetric radar in regions surrounding where lightning is initiated, to provide clues concerning electrification mechanisms and the processes responsible for producing electric field magnitudes large enough to initiate lightning. Besides analyzing the microphysical conditions surrounding regions of initiation in typical storms and in storms with inverted polarity electrical structure, the PI will analyze cases in which lightning is initiated in anvils 50-100 km downshear from the main body of the storm and cases with steady rates of 1-4 VHF sources per second in the overshooting tops of strong isolated storms. These behaviors have been observed only recently and little is known about their characteristics and the cause of their occurrence. 2. Analyze how lightning in the stratiform precipitation region of MCSs is affected by variations in the kinematics and microphysics of systems having different modes of organization. Thus far, all published studies of in-cloud lightning structure in the stratiform region have examined leading-line, trailing-stratiform MCSs. The PI plans to analyze strongly asymmetric MCSs having a northern stratiform region formed by a mesovortex and to analyze systems with other forms of organization, to ascertain the effect of the mode of organization on lightning and charge structure. One would expect, for example, that asymmetric MCSs, which often have weaker convective cells to their north, would tend to have less lightning in the stratiform region, and that a strong mesovortex would be reflected in the structure of any lightning in the stratiform region. Data for both asymmetric and complex MCSs are ready for analysis. Broader Impacts: This project will provide research experience for three graduate students and two undergraduate students. The participation of females and under-represented minorities will be encouraged. Field programs are planned in Oklahoma during the period in which students will have the opportunity to participate and to learn skills involved in making storm observations. Much of the knowledge gained from the research will help efforts to develop applications of lightning data for weather operations, in preparation for the launch of an optical lightning mapper on the GOES-R satellite.

“该奖项由 2009 年美国复苏和再投资法案（公法 111-5）资助。” 智力优势：根据该奖项，首席研究员 (PI) 将继续研究微物理和运动学如何影响风暴带电和闪电产生，方法是使用自 2003 年以来在俄克拉荷马州获得的闪电测绘、电场、雷达和其他风暴观测数据。俄克拉荷马州闪电测绘阵列，当地国家气象局11 厘米极化雷达和快速扫描 10 厘米相控阵雷达已运行数年。 在2003年和2004年雷暴电气化和闪电实验（TELEX）期间以及此后的其他场合，还收集了额外的观测数据，包括电场的原位风暴探测、环境探测和移动5厘米波长双多普勒雷达数据对于选定的案例。 这些情况包括各种类型的中尺度对流系统（MCS）、超级单体风暴和其他孤立风暴。 PI 将重点分析两大主题： 1. 分析由极化雷达推断出的闪电发生周围区域的微物理和运动学条件，以提供有关电气化机制和负责产生足以引发闪电的电场强度的过程的线索。 除了分析典型风暴和具有反极性电结构的风暴引发区域周围的微物理条件外，PI还将分析在距离风暴主体下切变50-100公里的砧处引发闪电的情况以及稳定速率的情况在强孤立风暴的过冲顶部，每秒有 1-4 个 VHF 源。 这些行为直到最近才被观察到，并且对其特征和发生原因知之甚少。 2. 分析具有不同组织模式的系统的运动学和微物理变化如何影响MCS层状降水区的闪电。 到目前为止，所有已发表的关于层状区域云内闪电结构的研究都检查了前导线、尾随层状 MCS。 PI计划分析具有由中涡形成的北部层状区域的强不对称MCS，并分析具有其他组织形式的系统，以确定组织模式对闪电和电荷结构的影响。 例如，人们预计，不对称的MCS（其北部通常有较弱的对流单元）在层状区域中的闪电往往较少，并且强中涡旋将反映在层状区域中任何闪电的结构中。非对称和复杂 MCS 的数据已准备好进行分析。更广泛的影响：该项目将为三名研究生和两名本科生提供研究经验。 将鼓励女性和代表性不足的少数群体的参与。 俄克拉荷马州计划进行实地考察，学生将有机会参与并学习风暴观测技能。 从研究中获得的大部分知识将有助于开发闪电数据在天气操作中的应用，为在 GOES-R 卫星上发射光学闪电测绘仪做好准备。