Kinetic Effects on MHD Phenomena in the Magnetosphere

对磁层 MHD 现象的动力学影响

• 批准号: 9523331
• 负责人: Chio Cheng
• 金额: $ 40.45万
• 依托单位: Department of Energy, Princeton Plasma Physics Laboratory
• 依托单位国家: 美国
• 项目类别: Interagency Agreement
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9523331&HistoricalAwards=false
• 关键词: Kinetic; Effects; MHD; Phenomena; Magnetosphere

This investigation deals with theory and data analysis related to kinetic effects on magnetohydrodynamic (MHD) phenomena in the magnetosphere. When MHD activity is strongly affected by particle kinetic effects such as finite gyro-radius effects, trapped particle effects and wave-particle resonance effects, traditional MHD approaches break down. The kinetic-MHD approach to be applied in this study will provide a theoretical and observational basis for understanding kinetic effects on MHD phenomena such as Pc 4-5 magneitic pulsations and magnetospheric substorms. Formulae for computing plasma instability parameters from the particle data will be obtained from this investigation. By comparing theoretical calculations with the plasma stability paramters obtained from space-based instruments, the investigators will be able to study the relationship between observed plasma properties and MHD activity in the space environment. If the theoretical kinetic-MHD stability analysis is verfied, one can perform a real-time numerical stability analysis based on in situ satellite particle and magnetic field data and realistic magnetospheric equilibria. Such an excerise could lead to advanced warning f the onset of violent MHD activity and the associated high energy particle flux that creates adverse space weather conditions.

这项研究涉及与磁层中磁流体(MHD)现象的动力学效应有关的理论和数据分析。当MHD活动受到有限回转半径效应、囚禁粒子效应和波粒共振效应等粒子动力学效应的强烈影响时，传统的MHD方法就失效了。本研究中将采用的动力学-MHD方法将为理解动力学效应对MHD现象的影响提供理论和观测基础，如Pc4-5磁脉动和磁层亚暴。从粒子数据计算等离子体不稳定性参数的公式将从这项研究中得到。通过将理论计算与从天基仪器获得的等离子体稳定性参数进行比较，研究人员将能够研究观测到的等离子体性质与空间环境中MHD活动之间的关系。如果理论动力学-MHD稳定性分析得到验证，就可以根据现场卫星粒子和磁场数据以及现实的磁层平衡进行实时数值稳定性分析。这样的演习可能会提前警告猛烈的MHD活动的开始，以及相关的高能粒子通量，这会造成不利的空间天气条件。