GEM: Modeling Dynamics of the Radiation Belts Using Scattering Rates Computed in a Realistic Magnetic Field and Accounting for Adiabatic Effects

GEM：使用在现实磁场中计算的散射率并考虑绝热效应来对辐射带动力学进行建模

• 批准号: 1203747
• 负责人: Yuri Shprits
• 金额: $ 28.2万
• 依托单位: University of California-Los Angeles
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-06-15 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1203747&HistoricalAwards=false
• 关键词: GEM; Modeling; Dynamics; Radiation; Belts

This project will enhance the already existing Versatile Electron Radiation Belt (VERB) model of Earth's radiation belts to include effects that result from the fact that the magnetic field is not a simple dipolar field. The new model will include the effects of adiabatic variations particle fluxes as well as the effects of magnetic local time (MLT) dependent pitch-angel and energy scattering. The Full Diffusion Code (FDC) will be modified to compute scattering rates in a realistic non-dipolar field for various MLT sectors and different values of geomagnetic activity. Comparisons with observations and numerical sensitivity experiments will significantly improve our understanding of dominant acceleration and loss processes in the radiation belts and will provide important tools for understanding data from several upcoming satellite missions. Key questions that will be examined are: (1) what are the mechanisms responsible for the acceleration of particles in the radiation belts? (2) what mechanisms are responsible for the loss of particles from the radiation belts? (3) How does the stretched, non-dipolar magnetic field affect resonant interactions between magnetospheric waves and the radiation belt electrons? (4) How do pitch-angle scattering and energy diffusion vary as a function of radial distance from the Earth (L-shell), the magnetic local time and geomagnetic activity? (5) How does drift-shell splitting affect the phase space density of the particles? This comprehensive analysis will make it possible to quantify the adiabatic effects and also compare the adiabatic changes to the non-adiabatic energization, scattering, and radial transport.Understanding the interactions of magnetospheric waves with the energetic particles in the radiation belts is important for understanding and predicting space weather phenomena. In addition to the relevance of the work to space weather, the project is directly relevant to NSF's Geospace Environment Modeling program. Much of the research for this project will be carried out by a graduate student and a postdoctoral researcher. The project also has relevance to several upcoming space missions such as NASA's Radiation Belt Storm Probe mission.

该项目将加强现有的地球辐射带多功能电子辐射带模型，以包括磁场不是简单的偶极场这一事实所产生的影响。 新的模型将包括绝热变化的影响，粒子通量以及磁局部时（MLT）相关的俯仰角和能量散射的影响。全扩散代码（FDC）将被修改，以计算散射率在一个现实的非偶极场的各种MLT部门和不同的地磁活动值。与观测和数值敏感性实验的比较将大大提高我们对辐射带主要加速和损失过程的理解，并将为理解几个即将到来的卫星飞行任务的数据提供重要工具。 将要研究的关键问题是：（1）辐射带中粒子加速的机制是什么？(2)辐射带的粒子流失是由什么机制造成的呢？(3)拉伸的非偶极磁场如何影响磁层波和辐射带电子之间的共振相互作用？(4)俯仰角散射和能量扩散是如何随着与地球的径向距离（L壳层）、磁地方时和地磁活动而变化的？(5)漂移壳层分裂如何影响粒子的相空间密度？ 这种全面的分析将使量化绝热效应成为可能，并将绝热变化与非绝热辐射、散射和径向输运进行比较，了解磁层波与辐射带中高能粒子的相互作用对于理解和预测空间天气现象非常重要。 除了与空间天气相关的工作外，该项目还与NSF的地球空间环境建模计划直接相关。 该项目的大部分研究将由一名研究生和一名博士后研究员进行。 该项目还与几个即将到来的太空任务有关，如NASA的辐射带风暴探测使命。