Theoretical Studies of Solar Wind-Magnetosphere-Ionosphere Coupling on Intermediate Scales

研究了太阳风、磁层和电离层的中等尺度、随时间变化的耦合。这项研究将有助于详细研究能量、动量和质量如何从太阳风转移到磁层顶，进入磁层，并沿着极光场线进入电离层。我们将用解析和数值方法来描述磁层顶局部重联的动力学，以及重联与等离子体的脉冲穿透和磁层顶对太阳风中动态气压扰动的响应之间的关系。以前开发的一个数值模型将用来描述磁层对磁层顶驱动扰动的全球响应。在更局部化的尺度上，正在开发一个三维模型，以描述极光电流与电离层的详细相互作用。这个模型，连同伴随的解析理论，将被用来描述由于阿尔芬速度在电离层上方急剧增加而形成的空腔中的阿尔芬波的陷阱。这项研究计划的总体目标是理解和模拟从太阳风到电离层的能量耦合的等离子体过程。

A study of the intermediate scale, time-dependent coupling of the solar wind, magnetosphere and ionosphere is proposed. Such a study will allow for a detailed investigation of how energy, momentum and mass is transferred from the solar wind across the magnetopause, into the magnetosphere, and along auroral field lines into the ionosphere. Both analytic and numerical techniques will be used to describe the dynamics of localized reconnection at the magnetopause, and the relation of reconnection to the impulsive penetration of plasma and to the response of the magnetopause to dynamic pressure perturbations in the solar wind. A previously developed numerical model will be used to describe the global response of the magnetosphere to driving perturbations at the magnetopause. On a more localized scale, a three-dimensional model is being developed to describe the detailed interaction of auroral currents with the ionosphere. This model, along with accompanying analytic theory, will be used to describe the trapping of Alfven waves in the cavity formed by the sharp increase of the Alfven speed above the ionosphere. The overall goal of this research program is the understanding and modeling of the plasma processes which couple energy from the solar wind to the ionosphere.