SHINE: Understanding the Impact of Solar Energetic Particles and Forbush Decreases on the Global Electric Circuit

太阳高能粒子(SEP)被认为是最大的空间气象灾害。这些粒子在传播到地球时，会给宇航员、卫星上的电子设备以及其他人类建造的基础设施和技术带来风险。此前的研究表明，SEPS甚至可以影响地球气候。当这些粒子在地球大气层中沉淀下来时，它们通过电离储存能量，改变大气化学，并导致云的形成。与SEP有关的空间天气现象和对流层气候之间的耦合对人类环境可能是必不可少的，这种耦合在一定程度上是通过全球电路(GEC)存在的。对这种耦合的透彻理解需要透彻地理解GEC如何响应SEPS和福布什减少(FDs)，并且需要来自日球层物理、宇宙线物理和大气物理的研究人员的合作努力。该项目是一项跨学科研究，旨在增加对SEP如何影响全球气候变化和陆地天气或气候的了解。这项提议将支持一名博士后和一名暑期研究生，从而有助于培养下一代空间等离子体和大气科学家。这项工作旨在了解SEP和FDs对全球电路的影响。它将侧重于在晴朗天气条件下测量的电位梯度(PG)如何响应全球的SEP和FDs，以及闪电如何响应SEPS和FDs。该方法将包括数据分析和数值模拟。为了实现科学目标，该团队将：1)研究晴朗天气条件下PG增加与站点高度和磁纬度之间的关系；2)确定SEPS和太阳风特征与晴朗天气条件下PG增加之间的可能关系；3)确定福布什下降特征与晴朗天气条件下PG增加之间的可能关系；4)通过将观测到的PG增加与蒙特卡罗模拟进行比较，了解SEP事件期间的全球电离廓线；5)调查SEP事件和闪电之间的关系。这一裁决反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Solar Energetic Particle (SEP) are identified as the top space weather hazard. These particles, when propagating to the Earth, create risks to astronauts, electronics onboard satellites, and to other human-built infrastructure and technology. Previous studies have suggested that SEPs can even influence Earth’s climate. As these particles precipitate down in the Earth’s atmosphere, they deposit their energy through ionization, modify atmospheric chemistry, and lead to cloud formation. The coupling between SEP-related space weather phenomena and tropospheric climate can be essential for the human environment, and this coupling exists, in part, through the Global Electric Circuit (GEC). A thorough understanding of this coupling requires a thorough understanding of how the GEC responds to SEPs and Forbush Decreases (FDs), and requires collaborative efforts from researchers from heliospheric physics, cosmic ray physics, and atmospheric physics. This project is an interdisciplinary study to increase understanding on how SEPs affect the GEC and terrestrial weather or climate. This proposal will support one postdoc and a summer graduate student, therefore helping to train the next generation of space plasma and atmospheric scientists. This work aims to understand the effect of SEPs and FDs on the Global Electric Circuit. It will focus on how the measured potential gradient (PG) in fair weather conditions responds to SEPs and FDs across the globe and how lightning respond to SEPs and FDs. The methodology will involve both data analysis and numerical simulation. To achieve the science goals the team will, 1) Examine the correlation between PG increases in fair weather conditions and station altitude and magnetic latitude; 2) Identify the possible relationship between the characteristics of SEPs and solar wind and the PG increases in fair weather condition; 3) Identify the possible relationship between Forbush Decrease characteristics and PG increases in fair weather conditions; 4) Understand the global ionization profiles during SEP events by comparing observations of PG increases with Monte-Carlo simulations; and 5) Investigate the relationship between SEP events and lightning.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.