Electrical Structure of Storm Systems that Produce Positive Cloud-to-Ground Lightning

9807179比斯利云地闪电是一种降低地面正电荷(CG+)而不是负电荷的闪电，因为它们是异常的，特别是能量大的，并且具有不寻常的电流特征，所以一直是密集研究的对象。过去的研究表明，CG+往往出现在特定的对流风暴情况下，并在某种程度上与最近发现的“精灵”有关，“精灵”是从雷暴顶部向高层大气排放的物质。首席调查人员将参与一个大型合作项目，研究产生CG+的风暴的电学、动力学和微物理特征。该项目被称为中尺度对流系统电化和极化雷达研究(MEaPRS)，将利用各种仪器观测云的微物理、X射线、电场和电场变化、闪电位置、雷达反射率、风和极化雷达变量。这项研究将利用气球载测量和数值云模拟来研究中尺度对流系统(MCSs)和产生正云对地闪电的孤立强风暴中的电场和电荷分布。在这些类型的风暴中，地面正闪的发生已经被记录在案，但对风暴的电学结构还没有很好的了解。在一些MCS中已经获得了电场和电荷密度的垂直分布，这些MCS通常在层状区产生零散的正地闪。已经有足够的剖面来建立风暴？S电气结构的概念模型，该模型已经由几个事例合成。从未对单个MCS的所有主要区域的电气特性进行过采样。拟议研究的目标是获得电场和粒子电荷的观测，以评估这些充电过程中的每一个对观测到的电荷分布的相对贡献。将在各个MCS的所有主要区域进行探测，以确定电荷的分布和时间发展，特别是在层状区。***

9807179BeasleyCloud-to-ground lightning flashes that lower positive (CG+), rather than negative, charge to ground have been the object of intense study because they are anomalous, particularly energetic, and have unusual current characteristics. Past research has shown that CG+ tend to occur in specific convective storm situations and also are connected in some way with the recently discovered "sprites", which are discharges from thunderstorm tops to the upper atmosphere. The Principal Investigators will participate in a large cooperative project to study the electrical, dynamical and microphysical characteristics of storms that produce CG+. This project, knows as the Mesoscale Convective System Electrification and Polarimetric Radar Study (MEaPRS), will bring to bear a variety of instruments to observe cloud microphysics, x-rays, electric field and field changes, lightning strike locations, radar reflectivity, winds, and polarimetric radar variables.This research will employ balloon-borne measurements and numerical cloud modeling to study the distribution of the electric field and charge in mesoscale convective systems (MCSs) and in isolated severe storms that produce positive cloud-to-ground lightning. The occurrence of positive ground flashes in these types of storms has been documented, but the electrical structures of the storms are not yet well understood.Vertical profiles of electric field and charge density have been acquired in a few MCSs, which typically produce scattered positive ground flashes in the stratiform region. There have been enough profiles to develop a conceptual model of the stormÆs electrical structure that has been composited from several cases. Never have the electrical characteristics of all the major regions of a single MCS been sampled. A goal of the proposed research is to obtain observations of electric field and particle charge to evaluate the relative contribution of each of these charging processes to observed charge distributions. Soundings will be made in all of the major regions of individual MCSs to determine the distribution and temporal development of charge, especially in the stratiform region. ***