Microphysical and Kinematic Storm Properties Affecting Electrification and Lightning Production

“这个奖项是根据2009年美国复苏和再投资法案(公法111-5)资助的。”学术价值：根据这个奖项，首席调查员(PI)将通过使用自2003年以来在俄克拉何马州获得的闪电测绘、电场、雷达和其他风暴观测，继续调查微观物理和运动学如何影响风暴带电和闪电产生。俄克拉荷马州闪电测绘阵列、当地国家气象局11厘米偏振雷达和一台快速扫描10厘米相控阵雷达已经运行了几年。在2003年和2004年的雷暴带电和闪电实验(电传)期间以及此后的其他场合，还收集了部分案例的其他观测数据，包括现场风暴电场探测、环境探测和移动5厘米波长双多普勒雷达数据。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的风暴。PI将重点分析两个广泛的主题：1.分析从偏振雷达推断的闪电周围地区的微物理和运动学条件，以提供关于带电机制和产生足够大到足以引发闪电的电场的过程的线索。除了分析典型风暴和具有反极性电性结构的风暴起始区周围的微物理条件外，PI还将分析闪电在距风暴主体50-100公里的下切变中引发的情况，以及强孤立风暴的超射顶部以每秒1-4个VHF源的速度稳定的情况。这些行为只是最近才被观察到，对它们的特征和发生的原因知之甚少。2.分析了不同组织方式系统的运动学和微物理变化对MCSs层状降水区闪电的影响。到目前为止，所有已发表的关于层状区云内闪电结构的研究都考察了前线、拖尾层状MCS。PI计划分析具有由中涡形成的北部层状区的强不对称MCS，并分析具有其他组织形式的系统，以确定组织方式对闪电和电荷结构的影响。例如，人们会认为，不对称的MCS，其北部往往有较弱的对流单体，层状区的闪电往往较少，而层状区中任何闪电的结构都会反映出一个强大的中涡旋。非对称和复杂MCS的数据都已准备好进行分析。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参与。在俄克拉荷马州，学生将有机会参与并学习风暴观测所涉及的技能，并计划在这段时间内进行实地考察。从研究中获得的许多知识将有助于努力开发用于天气业务的闪电数据应用，为在GOES-R卫星上发射光学闪电测图仪做准备。

"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.