Theory and Simulations of Ionosphere-Magnetosphere Coupling Dynamics

极光研究的一个重要部分是了解极光电流系统的产生和极光电子的加速(对地面上可以看到的极光发射负有责任)。这笔赠款涉及三个独立但相关的主题，涉及磁层-电离层系统的耦合、能量学和动力学以及阿尔芬波引起的极光加速过程。第一个主题是研究电离层空穴及其与极光弧破裂的关系。第二个专题是低纬边界层的切变流发生器与极光电离层的耦合。第三个主题是研究阿尔芬波破裂导致极光电子加速的新机制。这些研究将主要通过使用流体模型的流体模拟进行，但第三个主题将使用混合动力学模拟。

An important part of auroral research is to understand the generation of the auroral current systems and the acceleration of auroral electrons (responsible for the auroral emissions which can be seen on the ground). This grant addresses three separate but related topics which are concerned with the coupling, energetics, and dynamics of the magnetosphere-ionosphere system and the auroral acceleration process due to Alfven waves. The first topic is an investigation of the ionospheric cavity and its relationship to auroral arc breakup. The second topic is the coupling of the shear flow generator at the low latitude boundary layer to the auroral ionosphere. The third topic is an investigation of a new mechanism for auroral electron acceleration due to Alfven wave breaking. These investigations will be carried out primarily through fluid simulations using fluid models though a hybrid kinetic simulation will be used for the third topic.