CEDAR: Dynamics of SAPS (SubAuroral Polarization Streams) during Geomagnetic Disturbances and Their Effects on the Coupled Ionosphere-Thermosphere System

CEDAR：地磁扰动期间 SAPS（亚极光偏振流）的动力学及其对电离层-热层耦合系统的影响

• 批准号: 1342968
• 负责人: Shasha Zou
• 金额: $ 34.69万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-05-01 至 2018-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1342968&HistoricalAwards=false
• 关键词: CEDAR; Dynamics; SAPS; SubAuroral; Polarization

This project aims to comprehensively investigate the dynamics of SubAuroral Polarization Streams (SAPS) during geomagnetic disturbances and their effects on the ionosphere and thermosphere (IT). The dynamics of SAPS is an outstanding magnetosphere-ionosphere coupling problem associated with the electrodynamics at the interface between the hot and cold particle populations in the inner magnetosphere. The generation mechanisms of SAPS during geomagnetic active times, in particular substorms, are still not well understood, nor are the wave-like oscillations embedded within SAPS, or the effects of SAPS on the global IT system. Ground-based observations (Super Dual Auroral Radar Network (SuperDARN), Poker Flat Incoherent Scatter Radar (PFISR) and all-sky imager arrays) and space-based measurements (Time History of Events and Macroscale Interactions during Substorms (THEMIS) and the Van Allen probes), as well as the Global Ionosphere Thermosphere Model (GITM), will be used to carry out an integrated study of the dynamics of SAPS and their effects on the coupled IT system. Specific objectives are (1) to statistically construct the distribution of response times of SAPS intensifications relative to substorm onset and the distribution of intensification durations, and investigate the underlying mechanisms responsible for the SAPS intensification and for variable time delays, (2) to characterize the wave activity within the SAPS and their magnetospheric counterparts and identify the nature of the wave activity, and (3) to quantitatively evaluate the role of ion precipitation in affecting the SAPS evolution and the effect of the SAPS intensification after substorm onset and the wavy-structures of SAPS on the IT system using GITM. This project will support the professional development of two young researchers, including one female. It will also involve participation of a graduate student and summer REU students. Project results will be disseminated broadly. The project is interdisciplinary and will be valuable to the GEM (Geospace Environment Modeling) community, and contribute to an improved understanding of space-weather events.

该项目旨在全面调查地磁扰动期间亚极光偏振流的动态及其对电离层和热层的影响。SAPS的动力学是一个突出的磁层-电离层耦合问题，它与磁层内热粒子和冷粒子之间界面的电动力学有关。SAPS在地磁活跃期，特别是亚暴期间的产生机制，仍然没有得到很好的理解，也不是嵌入在SAPS内的波浪状振荡，或SAPS对全球IT系统的影响。地面观测（超级双极光雷达网、扑克牌平板非相干散射雷达和全天空成像仪阵列）和天基测量（亚暴期间事件和大尺度相互作用的时间历史（THEMIS）和货车艾伦探测器），以及全球电离层热层模型（GITM），将被用来进行综合研究的动态SAPS及其对耦合IT系统的影响。具体目标是：（1）统计地建立SAPS增强相对于亚暴开始的响应时间分布和增强持续时间分布，并调查导致SAPS增强和可变时间延迟的潜在机制，（2）描述SAPS及其磁层对应物内的波活动，并确定波活动的性质，（3）利用GITM定量分析了离子降水对SAPS演变的影响，以及亚暴爆发后SAPS的增强和SAPS的波结构对IT系统的影响。该项目将支持两名年轻研究人员的专业发展，其中包括一名女性。它还将涉及研究生和夏季REU学生的参与。项目成果将广泛传播。该项目是跨学科的，将对地球空间环境建模（GEM）界很有价值，并有助于增进对空间气象事件的了解。