Understanding Storm-Time Electromagnetic Ion Cyclotron (EMIC) Wave Occurrences and Their Relationship to Ground Signatures

了解风暴期间电磁离子回旋加速器 (EMIC) 波的发生及其与地面特征的关系

• 批准号: 1338221
• 负责人: Hyomin Kim
• 金额: $ 23.58万
• 依托单位: Virginia Polytechnic Institute and State University
• 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: 2014-08-15 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1338221&HistoricalAwards=false
• 关键词: Understanding; Storm; Time; Electromagnetic; Ion

The dynamics of the charged particles in the radiation belts has become an increasingly important science problem is recent years as society has become dependent on satellites in space. This is a project to investigate electromagnetic ion cyclotron waves (EMIC) in the space and their signatures on the ground. This project is well timed to support the NASA Van Allen Probes mission. It will support the work of a young scientist just starting his career.Radiation belt particles can be heated, scattered and lost in their interaction with EMIC waves. The investigators will study the propagation characteristics of the waves as a function of geomagnetic activity and radiation belt dynamics. Since ground observations of the waves are much easier and cheaper than satellite observations being able to study them from the ground would be very useful. They will use GOES and THEMIS magnetic field data from space along with conjugate data from the ground in Antarctica to address three questions: 1.) What is the relative occurrence of EMIC waves both in space and on the ground during each phase of a magnetic storm? 2.) Why are some of the waves not observed on the ground during certain phases (main and recovery) of the storm even though they are observed in space? 3.) How do heavy ions, He+ and O+, contribute to radiation belt precipitation losses and EMIC propagation to the ionosphere? This statistical study will be augmented by plasma data from LANL and THEMIS spacecraft. Finally they will join with unfunded collaborators at PPPL who will carry out wave simulation studies using a two-dimensional finite element code. This part of the study will investigate attenuation of the waves by heavy ions.

近年来，随着人类社会对太空卫星的依赖，辐射带中带电粒子的动力学已成为一个日益重要的科学问题。这是一个研究太空中的电磁离子回旋波及其在地面上的特征的项目。这个项目是支持美国宇航局范艾伦探测器任务的好时机。它将支持一位刚刚开始他的职业生涯的年轻科学家的工作。辐射带粒子在与地源波的相互作用中会被加热、散射和丢失。研究人员将研究地震波的传播特性作为地磁活动和辐射带动力学的函数。由于对引力波的地面观测要比卫星观测容易得多，成本也低得多，因此能够从地面对引力波进行研究将非常有用。他们将使用来自太空的GOES和THEMIS磁场数据以及来自南极洲地面的共轭数据来解决三个问题：在磁暴的每个阶段，空间和地面上的主位波的相对发生情况是什么？2.） 为什么在风暴的某些阶段（主要阶段和恢复阶段），即使在太空中可以观察到一些波浪，但在地面上却不能观察到它们？3.） 重离子He+和O+是如何导致辐射带降水损失和电磁场传播到电离层的？来自LANL和THEMIS航天器的等离子体数据将增强这项统计研究。最后，他们将与PPPL的无资助合作者一起使用二维有限元代码进行波浪模拟研究。这部分研究将研究重离子对引力波的衰减。