Differentiating Between the Leading Processes for Electron Radiation Belt Acceleration
Differentiating Between the Leading Processes for Electron Radiation Belt Acceleration
复制标题
DOI：
10.3389/fspas.2022.896245
复制
发表时间：
2022-06
期刊：
影响因子：
--
通讯作者：
S. Lejosne;H. Allison;L. Blum;A. Drozdov;M. Hartinger;M. Hudson;A. Jaynes;L. Ozeke;E. Roussos-E.-R
中科院分区：
文献类型：
--
作者：
S. Lejosne;H. Allison;L. Blum;A. Drozdov;M. Hartinger;M. Hudson;A. Jaynes;L. Ozeke;E. Roussos-E.-R
许多航天器在一个由磁层和太阳风之间的耦合提供动力的自然和可变粒子加速器内或通过该加速器飞行：地球辐射带。确定等离子体放电的主要途径是辐射带科学和空间天气学的核心挑战。来自外部源的向内径向输送最初被认为是辐射带中发生的最重要的加速过程。然而，当建模依赖于包括电子寿命的径向扩散方程时，模型-观测比较中的显著差异突出了改进的必要性。Richard M.教授的作品。索恩和其他人证明，高能（数百keV）电子与哨声模式的合唱波相互作用，可以有效地加速到非常高的能量。同样的原理很快被用来理解木星和土星的辐射带动力学。这些结果导致了我们对辐射带加速的理解发生了范式转变，并得到了观测结果的支持，观测结果表明，地球外带最具能量的电子的相空间密度的径向分布出现了一个不断增长的峰值。然而，量化的重要性，局部加速度的陀螺仪，与大规模的加速度与径向运输，仍然是有争议的，由于各种来源的不确定性。本综述的目的是提供背景，以了解与区分两个主要的辐射带加速过程：径向运输和局部加速的各种挑战。挑战范围从电子通量测量分析到基于三维福克-普朗克方程的辐射带建模。我们还提供了建议，为未来的研究辐射带径向运输和本地加速度。
Many spacecraft fly within or through a natural and variable particle accelerator powered by the coupling between the magnetosphere and the solar wind: the Earth’s radiation belts. Determining the dominant pathways to plasma energization is a central challenge for radiation belt science and space weather alike. Inward radial transport from an external source was originally thought to be the most important acceleration process occurring in the radiation belts. Yet, when modeling relied on a radial diffusion equation including electron lifetimes, notable discrepancies in model-observation comparisons highlighted a need for improvement. Works by Professor Richard M. Thorne and others showed that energetic (hundreds of keV) electrons interacting with whistler-mode chorus waves could be efficiently accelerated to very high energies. The same principles were soon transposed to understand radiation belt dynamics at Jupiter and Saturn. These results led to a paradigm shift in our understanding of radiation belt acceleration, supported by observations of a growing peak in the radial profile of the phase space density for the most energetic electrons of the Earth’s outer belt. Yet, quantifying the importance of local acceleration at the gyroscale, versus large-scale acceleration associated with radial transport, remains controversial due to various sources of uncertainty. The objective of this review is to provide context to understand the variety of challenges associated with differentiating between the two main radiation belt acceleration processes: radial transport and local acceleration. Challenges range from electron flux measurement analysis to radiation belt modeling based on a three-dimensional Fokker-Planck equation. We also provide recommendations to inform future research on radiation belt radial transport and local acceleration.