Electrification and Lightning of Severe Storms and Mesoscale Convective Systems in STEPS and on the Southern Great Plains

STEPS 和南部大平原强风暴和中尺度对流系统的电气化和闪电

• 批准号: 0233268
• 负责人: Donald MacGorman
• 金额: $ 87.76万
• 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: 2003
• 资助国家: 美国
• 起止时间: 2003-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0233268&HistoricalAwards=false
• 关键词: Electrification; Lightning; Severe; Storms; Mesoscale

This project is devoted to the study of relationships among the wind field, the electrical structure, the microphysics, and the lightning produced by both isolated thunderstorms and large systems of convective storms. It is based on the continuing analysis of data collected during the STEPS project of 2000 and includes collection of additional data in Oklahoma during the summers of 2003 and 2004. The data consist chiefly of balloon soundings of the electric field, polarimetric radar observations, and data from a lightning mapping array (LMA). Specific questions to be answered are: (1) Are lightning flash rates proportional to the mass of graupel in a storm? (2) Does the inverted electrical polarity of some storms have a microphusical cause? (3) Do the long horizontal flashes observed in mesoscale convective systems originate in the region of deep convection or in areas of lighter precipitation? (4) More generally, what are the characteristics of lightning flashes in mesoscale convective systems, and how are they affected by cloud microphysical structure? Answers to the question require synthesis of data from the different observing systems and analyzing the data in the light of different theories of charge production, separation, and lightning initiation. Results will contribute not only to the understanding of the physics of lightning, but will also be useful in developing techniques for assimilating lightning in numerical forecasting models and in learning how to use lightning data to warn of storm hazards. The work is done in collaboration with other participants in STEPS, in particular New Mexico Institute of Mining and Technology in the analysis of LMA data and Colorado State University in the analysis of polarimetric radar data.

这个项目致力于研究孤立的雷暴和大的对流风暴系统产生的风场、电气结构、微物理和闪电之间的关系。它基于对2000年STEPS项目期间收集的数据的持续分析，并包括2003年和2004年夏季在俄克拉荷马州收集的其他数据。这些数据主要由电场气球探测、极化雷达观测和闪电测绘阵列(LMA)数据组成。需要回答的具体问题是：(1)闪电率与风暴中的脉动质量成正比吗？(2)某些风暴的电极性反转是否有微尺度原因？(3)在中尺度对流系统中观察到的长水平闪电是起源于深对流区域还是降水较少的区域？(4)更一般的是，中尺度对流系统中闪电的特征是什么，它们是如何受云微物理结构影响的？这个问题的答案需要综合来自不同观测系统的数据，并根据不同的电荷产生、分离和闪电引发理论对数据进行分析。这些结果不仅将有助于理解闪电的物理学，而且将有助于开发在数值预报模式中吸收闪电的技术，并学习如何使用闪电数据来警告风暴危险。这项工作是与STEPS的其他参与者合作完成的，特别是与新墨西哥采矿和技术研究所合作分析LMA数据，与科罗拉多州立大学合作分析极化雷达数据。