MHD/particle simulations of radiation belt dynamics
MHD/particle simulations of radiation belt dynamics
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DOI：
10.1016/s1364-6826(02)00018-4
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发表时间：
2002-03
影响因子：
1.9
通讯作者：
S. Elkington;M. Hudson;M. Wiltberger;J. Lyon
中科院分区：
文献类型：
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作者：
S. Elkington;M. Hudson;M. Wiltberger;J. Lyon
外辐射带中的粒子通量可在时间上表现出很大的变化，范围从几分钟，如在地磁暴突然开始阶段，到与太阳周期进程有关的数年变化。由于组成这些带的高能粒子可能会对人类在太空中的活动构成危险，人们已经做出了相当大的努力来了解这些粒子的来源和支配它们动力学行为的物理学。通过计算跟踪模型磁层中的单个测试粒子代表了一种非常直接的、基于物理的方法来模拟风暴时间辐射带的动力学。利用地球-太阳系统的全球磁流体力学模型，结合辐射带的测试粒子模拟，我们通过两个例子表明，这种模拟能够在不同的时间尺度和地磁暴的所有阶段捕捉到外带辐射带的构型。这种模拟提供了一种基于物理的方法来研究外辐射区的动力学，并有望成为提供地磁活跃期辐射环境的全球短时预报的可行方法。
Particle fluxes in the outer radiation belts can show substantial variation in time, over scales ranging from a few minutes, such as during the sudden commencement phase of geomagnetic storms, to the years-long variations associated with the progression of the solar cycle. As the energetic particles comprising these belts can pose a hazard to human activity in space, considerable effort has gone into understanding both the source of these particles and the physics governing their dynamical behavior. Computationally tracking individual test particles in a model magnetosphere represents a very direct, physically-based approach to modeling storm-time radiation belt dynamics. Using global magnetohydrodynamic models of the Earth–Sun system coupled with test particle simulations of the radiation belts, we show through two examples that such simulations are capable of capturing the outer zone radiation belt configuration at a variety of time scales and through all phases of a geomagnetic storm. Such simulations provide a physically-based method of investigating the dynamics of the outer radiation zone, and hold promise as a viable method of providing global nowcasts of the radiation environment during geomagnetically active periods.