Meso-Scale Electrodynamic Coupling of the Earth Magnetosphere-Ionosphere System
Meso-Scale Electrodynamic Coupling of the Earth Magnetosphere-Ionosphere System
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DOI：
10.1007/s11214-022-00940-0
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发表时间：
2022-12
影响因子：
10.3
通讯作者：
Yiqun Yu;Jinbin Cao;Zuyin Pu;V. Jordanova;Aaron Ridley
中科院分区：
文献类型：
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作者：
Yiqun Yu;Jinbin Cao;Zuyin Pu;V. Jordanova;Aaron Ridley
在完全集成的磁层-电离层系统中，许多电动力学过程相互作用。本文综述了该系统中三个主要的中尺度耦合过程：瞬态场向电流、中纬度等离子体对流和极光粒子降水的研究进展。(1)瞬变FAC是由于日侧或夜间磁层的扰动而产生的。由于行星际激波突然压缩了日侧磁层，在高纬度地区诱发了短暂的FAC，它们的极性连续变化。磁尾动力学，例如亚暴注入，也可以扰乱电流结构，导致亚暴电流楔形的形成和环电流的破坏。(2)中纬等离子体对流与系统中的电场密切相关。最近的研究揭示了亚极光快流的一些重要特征和机制。(3)带电粒子在地球周围漂移时，往往会经历向下到高层大气的降水损失，从而增强极光的传导性。最近的研究致力于通过更好地表示极光电导来开发更自洽的地球空间环流模型。预计在地球空间环流模型中纳入这些新的进展将有望加强它们在空间气象应用方面的预报能力。文中还讨论了剩余的挑战，特别是在循环系统的全球建模方面。
Within the fully integrated magnetosphere-ionosphere system, many electrodynamic processes interact with each other. We review recent advances in understanding three major meso-scale coupling processes within the system: the transient field-aligned currents (FACs), mid-latitude plasma convection, and auroral particle precipitation. (1) Transient FACs arise due to disturbances from either dayside or nightside magnetosphere. As the interplanetary shocks suddenly compress the dayside magnetosphere, short-lived FACs are induced at high latitudes with their polarity successively changing. Magnetotail dynamics, such as substorm injections, can also disturb the current structures, leading to the formation of substorm current wedges and ring current disruption. (2) The mid-latitude plasma convection is closely associated with electric fields in the system. Recent studies have unraveled some important features and mechanisms of subauroral fast flows. (3) Charged particles, while drifting around the Earth, often experience precipitating loss down to the upper atmosphere, enhancing the auroral conductivity. Recent studies have been devoted to developing more self-consistent geospace circulation models by including a better representation of the auroral conductance. It is expected that including these new advances in geospace circulation models could promisingly strengthen their forecasting capability in space weather applications. The remaining challenges especially in the global modeling of the circulation system are also discussed.