GEM: Fundamental Properties of Dawnside Auroral Polarization Streams and Their Role in Magnetosphere-Ionosphere Instabilities and Dramatic Events

这项工作的重点是一个强大的电场，在地球的高层大气（或电离层），称为黎明极光偏振流（DAPS）流动的独特现象。DAPS是近地空间环境能量循环的一个基本组成部分，与造成系统中剧烈能量释放的不稳定性有关。由于DAPS的频繁扰动，它可以显著改变电离层的温度，进而改变电离层的组成和密度，从而影响低空航天器的阻力和电波传输的闪烁。该项目旨在了解DAPS的形成和后果，将为近地空间环境和空间天气预报的高级建模提供关键信息。这项资助的工作将促进早期职业科学家（PI）和职业女性研究人员的发展。该方案还将吸收对空间物理学感兴趣的本科生作为志愿者参加，并获得研究课程学分。这个项目涉及极光现象，所以很自然地吸引了普通大众。产品中的适当材料将通过教育和公共宣传工作传达给公众（包括K-12学生）。在极光椭圆的区域1电流部分内延伸的强向南电场和相关的向东流动被称为黎明极光偏振流（DAPS）。DAPS的强电场可以显著地改变磁层-电离层对流和高能粒子漂移，并加热电离层和热层。该项目旨在确定DAPS的基本属性及其影响，包括DAPS在不同条件下如何变化，导致这些变化的原因以及它们在导致戏剧性M-I事件的不稳定性中的作用。该团队将使用低空航天器观测（Swarm和DMSP）来测量磁场矢量和东西向流动，从而可以通过自动化方法识别FAC结构和DAPS。将这些方法应用于约20年的数据，该团队将进行全面的统计研究来回答这些问题。研究结果将为DAPS的产生机制及其对M-I系统对流、加热和不稳定性的影响提供重要信息。因此，这些研究的结果将为M-I能量循环提供重要的影响。鉴于DAPS的频繁发生和强度及其与主要电离层电导率变化的关系，该发现可能会对M-I-T建模产生变革性影响。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

This work focuses on a unique phenomenon of a strong electric field that flows in Earth’s upper atmosphere (or ionosphere), called Dawnside Auroral Polarization Streams (DAPS). The DAPS is an essential component of the energy circulation of the near-Earth space environment and is related to the instabilities responsible for dramatic energy releases in the system. Occurring frequently, DAPS can significantly modify the ionosphere temperature and thus its composition and density, which impact the drag of low-altitude spacecraft and the scintillation of radio wave transmission. Aiming at understanding the formation and consequences of DAPS, this project will provide crucial information for advanced modeling of the near-Earth space environment and space weather prediction. This funded work will promote the development of an early-career scientist (the PI) and a very early-career female researcher. It will also involve undergraduate students interested in space physics as volunteers and for research course credit. This project involves auroral phenomena, so it naturally appeals to the general public. Appropriate materials from the products will be conveyed to the public (including K-12 students) via education and public outreach efforts.The strong southward electric field and associated eastward flow that extends within the Region 1 current portion of the auroral oval are referred to as the Dawnside Auroral Polarization Stream (DAPS). A DAPS’ strong electric field can significantly modify magnetosphere-ionosphere convection and energetic particle drift and heat the ionosphere and thermosphere. This project aims to determine fundamental DAPS properties and their impacts, including how DAPS vary under different conditions, what contributes to these variations, and their role in instabilities responsible for dramatic M-I events. The team will use low-altitude spacecraft observations (Swarm and DMSP) to measure a magnetic field vector and east-west flow, from which they can identify FAC structures and DAPS with automated methods. Applying these methods to ~20 years of data, the team will conduct comprehensive statistical studies to answer the questions. The research results will provide crucial information on DAPS’ generation mechanism and its impacts on the M-I system's convection, heating, and instability. The outcome of the studies will thus provide important implications for the M-I energy circulation. Given the frequent occurrence and strength of DAPS and their relationship to a major ionospheric conductivity change, the findings will likely be transformational for M-I-T modeling.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.