Collaborative Research: Energetic Particle Precipitation Mechanisms in the Inner Magnetosphere: Van Allen Probes and Incoherent Scatter Radar Coordinated Measurements

合作研究：内磁层中的高能粒子沉淀机制：范艾伦探头和非相干散射雷达协调测量

• 批准号: 1732365
• 负责人: Ennio Sanchez
• 金额: $ 35.59万
• 依托单位: SRI International
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1732365&HistoricalAwards=false
• 关键词: Collaborative; Research; Energetic; Particle; Precipitation

This project will examine the mechanisms by which charged particles in Earth's magnetic field travel both out of and through the atmosphere. Identifying these mechanisms is important for understanding how the various layers of the near-Earth environment are coupled. Understanding the neutral and charged atmosphere has become of increasing interest for understanding the background in which space weather events play. Data from NSF supported facilities such as the Advanced Modular Incoherent Scatter Radar (AMISR) will be analyzed in conjunction with space craft data. This award will also fund two postdoctoral researchers.Current particle precipitation theories assume that energetic particles in the magnetosphere precipitate into the atmosphere after undergoing pitch-angle scattering into the loss cone due to interactions with waves at or near the geomagnetic equator. However, the experimental verification of the effect of the multiple candidate waves on the particles' pitch-angle distributions has not been definitively established. This project brings together height-resolved measurements of ionization in the ionosphere, in situ measurements of pitch-angle scattering in the inner magnetosphere, and multidisciplinary expertise to achieve closure for all wave modes that may be involved in electron precipitation mechanisms. Instances of temporally coincident Van Allen Probes' measurements of particles and waves in the radiation belt (or ring current) and Poker Flat Incoherent Scatter Radar (PFISR) measurements of particles precipitating into the ionosphere near the foot-point of the Van Allen Probes' flux tubes will be identified. The loss-cone distribution functions created by candidate waves for pitch-angle scattering using the quasi-linear diffusion equations will be calculated. Changes in the phase-space distribution of electrons that are produced by the electric and magnetic wave fields in the frequency range from a few Hz to several kHz will be quantified by applying UCLAs Full Diffusion Code to Van Allen Probes' particle and field measurements. Finally, a comparison of the ionization profiles produced in the atmosphere by loss cone distributions calculated from Van Allen Probes' data with the ionization profiles directly measured with PFISR.

该项目将检查地球磁场中带电颗粒在大气中和通过大气中传播的机制。识别这些机制对于理解近地环境的各个层如何耦合至关重要。了解中性和充电的气氛已成为了解太空天气活动的背景的日益兴趣。 NSF支持的设施（例如高级模块化散射雷达（AMISR））的数据将与太空工艺数据一起分析。该奖项还将为两名博士后研究人员提供资金。电流颗粒降水理论假设，由于与地震赤道处的波浪相互作用或附近的波浪相互作用，磁层中的能量颗粒会沉淀到大气中。但是，尚未确定对多个候选波对颗粒螺距角度分布的影响的实验验证。该项目汇集了电离层中电离的高度分辨测量值，原位测量内部磁层中的螺距角散射以及多学科专业知识，以实现所有可能与电子降水机制有关的波模式的关闭。将鉴定在辐射带（或环电流）中对颗粒和波浪的临时范围范围探针测量的实例，以及扑克平面不连贯的散射雷达（PFISR）测量的颗粒的测量值将标识进入电离层附近的电离层的颗粒。将计算由候选波创建的损失 - 曲线分布函数，用于使用准线性扩散方程进行音调角散射。通过将UCLAS完整扩散代码应用于Van Allen Probes的粒子和现场测量值，可以量化由电场和磁性波场在频率范围内产生的电子和磁性波场在频率范围内产生的电子的相位变化。最后，比较了从Van Allen探针数据计算出的损耗锥分布与用PFISR直接测量的电离曲线所产生的电离曲线。

项目成果

Global Survey of Electron Precipitation due to Hiss Waves in the Earth’s Plasmasphere and Plumes

• DOI: 10.1029/2021ja029644
• 发表时间: 2021-08
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: Q. Ma;Wen Li;X.‐J. Zhang;J. Bortnik;X. Shen;H. Connor;A. Boyd;W. Kurth;G. Hospodarsky;S. Claudepierre;G. Reeves;H. Spence