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

合作研究：量化雷暴对全球电路影响的气球运动

• 批准号: 1724558
• 负责人: Michael McCarthy
• 金额: $ 51.43万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-15 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1724558&HistoricalAwards=false
• 关键词: Collaborative; Research; Balloon; Campaign; Quantify

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.

这笔赠款将量化雷暴活动作为地球全球电路驱动因素的作用。所需的晴天垂直电场和电流密度测量值将在几天内获得。通过在平流层气球平台上使用经过充分验证的双朗缪尔探测器技术获得的高海拔、天气、地形和其他影响下的晴天电场和垂直电流密度的时间序列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表征，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。拟议工作的目的是以前所未有的准确性和深度检验雷暴活动是全球环流的主要驱动因素的假设。智力优点。 C. T. R. 威尔逊 (C. T. R. Wilson) 提出雷暴是全球电路的重要驱动因素已近 100 年前。实现这一目标需要对晴天电场的驱动因素进行定量评估。由于测量各种候选者（雷暴、带电云或其他中层大气电流源）的长期困难，这一目标仍然难以实现。此外，关于全球环路对雷暴源变化的短时响应的观测工作非常有限。该提案将测试连接假设，时间尺度为 100 秒。对全球活跃雷暴区域和垂直晴天电流密度的两个时间序列进行直接比较将使这个经典问题取得重大进展。由于高时间分辨率测量比以前的研究取得了实质性进展，这项工作可能会带来有关全球电路的新见解和问题。研究生的论文研究将因拟议的努力而得到支持。此外，每年夏天参与与气球飞行部署相关的分包工作的本科生也将得到支持。学生将接受仪器开发和校准、现场活动后勤、整理和分析多种类型的数据以及作为理解测量的手段的建模方面的培训。这笔赠款将为全球电路建模的持续努力提供重要的测量结果，也可能提供见解。我们对雷暴驱动因素的理解的预期改进对于在理解其他全球电路变化（例如太阳风效应、太阳质子事件或大规模大气温度变化）方面取得进展也至关重要。如果按照拨款的预期确定全球雷暴活动与平流层垂直电流密度之间存在强有力的关系，这将为使用少量仪器气球监测全球雷暴活动总量开辟可能性。