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.

这项工作着重于一个强大的电场的独特现象，该现象在地球上层大气（或电离层）中，称为黎明侧极光偏振（DAPS）。 DAPS是近地太空环境的能量循环的重要组成部分，与负责系统中急剧释放的不稳定性有关。经常发生，DAP可以显着改变电离层温度，从而改变其组成和密度，从而影响低空航天器的阻力和无线电波传播的闪烁。为了了解DAP的形成和后果，该项目将为近地太空环境和空间天气预测的高级建模提供重要信息。这项资助的工作将促进早期职业科学家（PI）和非常职业的女性研究人员的发展。它还将涉及对志愿者和研究课程学分有兴趣的本科生。该项目涉及极光现象，因此自然而然地看着公众。产品中的适当材料将通过教育和公共外展工作传达给公众（包括K-12学生）。强大的向南电场和相关的向东流延伸在Auroral椭圆形的区域1电流部分中，称为黎明侧极光极化流（DAPS）。 DAPS的强电场可以显着改变磁层 - 电离层的构造，并在电离层和热层中加热颗粒的颗粒漂移并加热。该项目旨在确定基本的DAPS属性及其影响，包括在不同条件下DAPS如何变化，有助于这些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。该团队将使用低海拔航天器观测值（SWARM和DMSP）来测量磁场矢量和东西方流量，他们可以从中识别出使用自动方法的FAC结构和DAPS。将这些方法应用于约20年的数据，团队将进行全面的统计研究以回答问题。研究结果将提供有关DAPS的发电机制及其对M-I系统的构建，供暖和不稳定的影响的关键信息。因此，研究的结果将为M-1能量循环提供重要的影响。鉴于DAP的经常出现和强度及其与主要电离层电导率变化的关系，这些发现可能是M-I-T建模的转化。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估来获得的支持。