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

GEM：黎明极光偏振流的基本特性及其在磁层-电离层不稳定性和戏剧性事件中的作用

• 批准号: 2247034
• 负责人: Jiang Liu
• 金额: $ 52.36万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2026-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2247034&HistoricalAwards=false
• 关键词: GEM; Fundamental; Properties; Dawnside; Auroral

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.

这项工作集中在一个强大的电场上，该电场在地球史道中流动（DAPS）是近地太空环境的能量循环的重要组成部分。在这里，温度和密度，这会影响低空航天器的阻力以及旨在理解和习惯的无线电波的闪烁WORL促进了Ann早期医生科学家（PI）的发展，而Berry早期的女性研究人员也将涉及对空间物理的志愿者感兴趣的学生。公众。影响的影响，包括在不同条件E变化下如何变化，以及它们在负责戏剧性M-I事件的不稳定性中的作用。使用自动化的方法因此，研究的结果将对M-1的能量循环产生影响。