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

9807179 BeasleyCloud-to-ground闪电降低了正电荷（CG+），而不是负电荷到地面，一直是深入研究的对象，因为它们是异常的，特别是能量，并且具有不寻常的电流特性。 过去的研究表明，CG+往往发生在特定的对流风暴情况下，也以某种方式与最近发现的“精灵”，这是从雷暴顶部到高层大气的排放。 主要研究人员将参与一个大型合作项目，研究产生CG+的风暴的电气，动力学和微物理特性。 该项目被称为中尺度对流系统电气化和偏振雷达研究（MEaPRS），将使用各种仪器观测云的微观物理学、x射线、电场和场变化、雷击位置、雷达反射率、风、和极化雷达变量。这项研究将采用气球-在中尺度对流系统（MCS）和孤立的强风暴，产生积极的云对地闪电的电场和电荷的分布进行研究的数值云模拟。 在这些类型的风暴正地闪的发生已被记录，但电结构的风暴还没有得到很好的理解。电场和电荷密度的垂直剖面已获得在少数MCS，这通常会产生分散的正地闪在层状区域。已经有足够的配置文件，以开发一个概念模型的风暴的电气结构，已合成从几个案例。 从未对单个MCS的所有主要区域的电气特性进行过采样。 拟议的研究的一个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观察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，特别是在层状区域。***

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. ***