Collaborative Research: Balloon Campaign to Quantify Thunderstorm Effects on the Global Electric Circuit

这项拨款将量化雷暴活动作为地球全球电路驱动因素的作用。晴天垂直电场和电流密度所需的测量将在几天内获得。在平流层气球平台上使用经过验证的双Langmuir探测器技术获得的高空晴天电场和垂直电流密度的时间序列，不受天气、地形和其他因素的影响，将与同期全球雷暴活动的特性进行比较。随着地面全球闪电探测网络的最新发展和特征，现在可以在分钟的时间尺度上检索全球雷暴区域及其不确定性。这项工作的目标是以前所未有的精确度和深度来检验雷暴活动是全球环流的主要驱动力这一假设。知识价值。在c.t.r.威尔逊提出雷暴是全球电路的重要驱动力近100年后。实现这一目标需要对公平天气电场的驱动因素进行定量评估。这个目标一直难以实现，因为长期以来难以测量各种各样的候选者：雷暴、带电云或其他中层大气电流源。此外，关于全球环流对雷暴源变化的短时间响应的观测工作非常有限。该提案将在100秒的时间尺度上测试这种联系假设。直接比较全球活跃雷暴面积和垂直晴天电流密度两个时间序列将使这一经典问题取得重大进展。由于高时间分辨率测量是以往研究的重大进步，这项工作可能会带来关于全球电路的新见解和新问题。研究生的论文研究将支持作为提议的努力的结果。此外，还将支助一名本科生参加每年夏天有关气球飞行部署的分包合同工作。学生将在仪器的开发和校准、野外战役后勤、整理和分析多种类型的数据以及建模作为理解测量的手段方面接受培训。这笔拨款将为正在进行的全球电路建模工作提供重要的测量方法，也可能提供见解。我们对雷暴驱动成分的理解的预期改进对于理解其他全球电路变化（如太阳风效应、太阳质子事件或大尺度大气温度变化）也至关重要。如果全球雷暴活动与平流层垂直电流密度之间的牢固关系如拨款所预期的那样被确定，这将为使用少量仪器化气球监测全球雷暴活动总量的前景打开可能性。

This grant would quantify the role of thunderstorm activity as a driver of Earth's global electric circuit. The required measurements of the fair weather vertical electric field and current density would be obtained over a period of several days. The time series of the fair weather electric field and vertical current density at high altitude, above weather, orographic, and other influences, obtained by using the well-proven technique of double Langmuir probes on a stratospheric balloon platform would be compared to properties of the contemporaneous global thunderstorm activity. With the recent development and characterization of ground-based global lightning detection networks, it is now possible to retrieve global thunderstorm area, and its uncertainty, on a timescale of minutes. The objective of the proposed work is to test the hypothesis, at unprecedented accuracy and depth, that thunderstorm activity is the primary driver for the global circuit. intellectual merit. Nearly 100 years after C. T. R. Wilson suggested thunderstorms are an important driver of the global electric circuit. Achieving this goal would require a quantitative evaluation of the drivers for the fair weather electric field. This goal has remained elusive due to a long-standing difficulty in measuring the various candidates: thunderstorms, electrified clouds, or other middle atmosphere current sources. Furthermore, there has been only very limited observational work on the short time response of the global circuit to variations in the thunderstorm source. This proposal will test thus connection hypothesis, at times scales of order 100 seconds. A straightforward comparison of the two time series of global active thunderstorm area and vertical fair weather electric current density would enable significant progress on this classic question. Because the high time resolution measurements are a substantial advance over previous investigations, this work will likely lead to new insights and questions about the global electric circuit. A graduate student's dissertation research would be supported as a result of the proposed effort. Moreover, an undergraduate student participating in the sub-contract effort relating to the flight deployment of the balloons each summer would be supported as well.Students will be trained in development and calibration of instrumentation, field campaign logistics, collating and analyzing multiple types of data, and modeling as a means to understand measurements. This grant would provide important measurements, and likely also insights, for ongoing efforts to model the global electric circuit. The anticipated improvement in our understanding of the thunderstorm driver component is also critical to achieving progress on understanding other global electric circuit variations such as from solar wind effects, solar protons events, or large scale atmospheric temperature change. If a robust relation between global thunderstorm activity and stratospheric vertical current density is identified as expected from the grant, this would open the possibility to the prospects of being able to monitor total global thunderstorm activity using a small number of instrumented balloons.