GEM: Modeling Ultra Low Frequency (ULF) Waves in the Near-Earth Magnetosphere

GEM：模拟近地磁层中的超低频 (ULF) 波

• 批准号: 1405383
• 负责人: Robert Lysak
• 金额: $ 45.56万
• 依托单位: University of Minnesota-Twin Cities
• 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: 2014-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1405383&HistoricalAwards=false
• 关键词: GEM; Modeling; Ultra; Low; Frequency

Ultra low frequency (ULF) waves are important for the transport of energy in the near-Earth magnetosphere. This research will improve a MHD wave code and apply it to several problems involving ULF waves in the magnetosphere. The outcome will be a global ULF wave model that can address the specific science questions in this proposal and provide an approach that can be applied to many other problems in magnetospheric physics. Specifically the proposal will address three questions:1. The propagation and dynamics of ULF waves in the inner magnetosphere, to understand the dynamics of the Pi1 and Pi2 pulsations found at substorm onset and their timing at both high and mid-latitudes with respect to driving sources in the magnetotail.2. The use of ULF waves to determine the mass density of the magnetosphere through travel-time and field-line resonance ?magnetoseismology?. 3. The coupling of high and low-latitude wave fields through the propagation of MHD waves through the magnetosphere and of electromagnetic waves in the Earth-ionosphere waveguide. This research will support a graduate student. The wave model will be very useful in other magnetosphere-ionosphere coupling studies. This model provides a missing link in our global models of magnetosphere and ionosphere coupling and therefore is important for space weather. As result it has high societal value.

超低频(ULF)波对于近地磁层中的能量传输非常重要。这项研究将改进MHD波程序，并将其应用于涉及磁层中的超低频波的几个问题。其成果将是一个全球超低频波模型，它可以解决这一提议中的具体科学问题，并提供一种可应用于磁层物理中许多其他问题的方法。具体而言，该提案将涉及三个问题：1.超低频波在内磁层的传播和动力学，以了解在亚暴开始时发现的Pi1和Pi2脉动的动力学，以及它们在高纬度和中纬度相对于磁源的时间安排。利用超低频波通过走时和场线共振来确定磁层的质量密度？？磁震学？3.通过磁层中的MHD波的传播和地球-电离层波导中的电磁波的传播，实现高纬和低纬波场的耦合。这项研究将支持一名研究生。该波模型在其他磁层-电离层耦合研究中将非常有用。这一模型在我们的全球磁层和电离层耦合模型中提供了缺失的一环，因此对空间天气很重要。因此，具有很高的社会价值。