Dynamical, Microphysical and Electrification Studies in Mid Latitude Convection

该奖项支持对2000年初夏在堪萨斯州西部进行的STEPS项目（强雷暴电气化和降水研究）观测结果的持续分析。利用极化雷达、飞机、探空气球和闪电测绘网的数据，研究了雷暴电气化与云的微物理和运动学特性之间的关系。特别注意的是那些表现出异常行为的风暴，如没有闪电，主要是正面的云对地闪电，或大量的云内闪电。激发这项工作的问题是：产生正闪电的云中正电荷的来源区域，将这些云与更典型的云区分开来的运动学和微物理差异，云内闪电在异常电荷结构的产生和维持中的作用，以及一旦对流发展，闪电的发生及其极性可以预测的程度。这项工作是与来自其他机构的STEPS研究人员合作完成的，涉及分析和综合来自两个s波段偏振雷达（科罗拉多州立大学的CHILL雷达和NCAR的S-Pol雷达）的数据，来自新墨西哥理工大学闪电测绘阵列的闪电三维地图，由南达科他州矿业和技术学院的T-28飞机获得的微物理和电气测量数据。以及由国家强风暴实验室的特殊气球测量的雷暴电场的垂直探测。该项目将使人们更好地了解风暴电气化，并找到监测和预测风暴强度的新方法。

This award supports continuing analysis of observations from the STEPS project (Severe Thunderstorm Electrification and Precipitation Study) conducted in western Kansas in the early summer of 2000. Data from polarimetric radar, aircraft, sounding balloons, and a lightning-mapping network are employed to investigate the relation between thunderstorm electrification and the microphysical and kinematic properties of clouds. Special attention is directed to storms that exhibit anomalous behavior such as the absence of lightning, predominantly positive cloud-to-ground lightning, or much intracloud lightning. Motivating the work are questions about the source region for the positive charge in clouds that produce positive lightning, the kinematic and microphysical differences that distinguish these clouds from the more typical ones, the role of intracloud lightning in the creation and maintenance of anomalous charge structures, and the extent to which the occurrence of lightning and its polarity can be predicted once convection develops. The work is done in collaboration with STEPS investigators from other institutions, and involves analysis and synthesis of data from two S-band polarimetric radars (the CHILL radar of Colorado State University and S-Pol of NCAR), 3-D maps of lightning flashes from the New Mexico Tech lightning-mapping array, microphysical and electrical measurements obtained by the storm-penetrating T-28 aircraft of South Dakota School of Mines and Technology, and vertical soundings of the thunderstorm electric field measured by special balloons of the National Severe Storms Laboratory. The project will lead to a better understanding of storm electrification and to new ways of monitoring and predicting storm intensity.