Dynamics of the near-Earth space environment

太空时代的黎明标志着历史上最激动人心的技术转变之一。在60年多一点的时间里，我们从一个没有人为地球轨道运行的世界变成了一个空间基础设施触及我们的日常生活并支撑着社会的许多关键基础设施的世界。对于等离子体物理学来说，太空时代是一次范式转变。看似一夜之间，卫星测量解锁了地球上的天然等离子体物理实验室，用一个封闭但可扩展的等离子体系统戏弄着研究人员。随着每一个新传感器的发射，近地空间被证明是一个高度动态的环境，跨越了巨大的空间、时间和能量尺度。再加上空间环境的巨大和等离子体系统(高层大气、磁层、太阳风等)之间相互联系的发现，人们在许多层面上对这个复杂系统的性质知之甚少。在全球空间物理研究界，我的小组侧重于近地高能(30keV)电子总数的动态，有两个核心主题：(1)地球空间中的通电、传输和损失过程，以及(2)对地球电离层和我们的技术系统的影响。高能电子在这个系统中很重要，因为它们不包含在太阳风中，因此完全由近地空间的自然等离子体过程提供能量。因此，了解这些人口是如何在系统内产生、运输和消失的，是了解空间环境的核心。一旦被激活，它们就被认为是“活跃的空间天气”，因为它们能够影响空间技术(和人类)，使它们成为空间利用的特别兴趣。在这份提案中，我提出了发展遥感仪器和传感器融合技术的愿景，以探测和解开这一严重低于采样领域的等离子体过程。为了应对这一挑战，我的计划将在了解耦合的空间环境和电离层系统的基本动力学方面取得重大进展，并为空间利用行业日益增长的需求创建新的数据应用程序。具体目标包括了解不同的等离子体波在造成电离层损失方面的效果如何，以及在什么条件下？就其对全球磁层高能电子预算的影响而言，不同的等离子体波有多重要？我的小组成员还在利用各种地面仪器研究与前沿空间天气预报模型的关键参数耦合以及预报对技术的影响。再加上我的仪器开发计划，这项提案中概述的研究将使我的团队能够利用新数据，开展新科学，并为研究高能电子布居、建立解释性模型和通向新的科学理解提供关键组成部分。

The dawn of the space age marked one of the most exciting technological transitions in history. In a little over 60 years we have gone from a world where nothing human-made had orbited the Earth to one in which space infrastructure touches our everyday lives and underpins much of society's critical infrastructure. For plasma physics, the space age has been a paradigm shift. Seemingly overnight, satellite measurements unlocked the Earth's natural plasma physics laboratory, teasing researchers with a close, yet expansive plasma system. With each new sensor launched, near-Earth space proved to be a highly dynamic environment coupled across vast spatial, temporal and energy scales. Compounded further by the sheer vastness of the space environment and the discovery of interconnections between plasma regimes (upper atmosphere, magnetosphere, solar wind, etc.), the nature of this complex system is poorly understood on many levels. Within the global space physics research community, my group focuses on the dynamics of the near-Earth high energy (>30keV) electron population with two core themes; (1) energization, transport and loss processes in geospace, and (2) impact on the Earth's ionosphere and our technological systems. High-energy electrons are important within this system since they are not contained in the solar wind and thus entirely energized by the natural plasma processes in near-Earth space. Understanding how this population is created, transported and lost within the system is thus core to understanding the space environment. Once energized they are considered "space weather active" due to their ability to impact technology (and humans) in space, making them of particular interest for space utilization. In this proposal I present my vision for developing remote sensing instrumentation and sensor fusion techniques to probe and untangle plasma processes in this severely under sampled domain. In addressing this challenge, my program will make significant progress in understanding fundamental dynamics in the coupled space environment and ionospheric systems, as well as create new data applications for the growing needs of space utilization industries. Specific goals include understanding how effective different plasma waves are in causing loss to the ionosphere, and under what conditions? and how important are the different plasma waves in terms of their impact on the global budget of high energy electrons in the magnetosphere? Members of my group are also utilizing the multitude of ground based instruments to study key parameter coupling to leading edge space weather prediction models and predicting impacts on technology. Coupled with my instrument development program, the research outlined in this proposal will position my group to leverage new data, conduct new science and provide a pivotal component for studying the high energy electron population, building interpretive models and a path toward new scientific understanding.