Transpolar Arcs and Hemispheric Asymmetry During Northward Interplanetary Magnetic Field (IMF)

了解磁层-电离层系统的动力学、两个区域之间的耦合及其对行星际条件的依赖，特别是对磁层和电离层物理学的几乎每一个方面都具有根本的重要性。在该项目中，使用了DMSP F12、F13、F14和F15等极地轨道卫星提供的电场和磁场以及降水粒子数据，同时极地紫外线成像仪提供极光发射测量数据。SuperDARN雷达阵列提供电离层对流图。Ace、Wind和IMP-8提供太阳风速度、密度和行星际磁场（IMF）测量。当极地紫外线指数提供极光分布的全球视图，并且至少有两颗DMSP卫星测量上电离层中的粒子特性、电场和场向电流时，就利用这段时间。利用这些数据的理解将提高跨极弧（TPAs）和θ极光在两个半球和详细的等离子体流与它们相关的发生。特别是，高纬度TPAs的存在是电离层中最不寻常的特征之一，意味着一种不寻常的磁层拓扑结构。TPAs的电动力学直接关系到在向北IMF期间太阳风-磁层-电离层系统之间如何发生耦合。对所描述的独特数据集的分析将提供对TPA在两个半球的同时行为和/或存在的深入了解，从而也提供对磁层拓扑结构的深入了解。

Understanding of the dynamics of the magnetosphere-ionosphere system, the coupling between the two regions, and its dependence on interplanetary conditions in particular, is of fundamental importance to almost every aspect of magnetospheric and ionospheric physics. In this project, electric and magnetic field and precipitating particle data from polar orbiting satellites such as DMSP F12, F13, F14 and F15, are used while the Polar UVI instrument provides measurements of auroral emissions. The SuperDARN radar array provides ionospheric convection maps. Ace, Wind, and IMP-8 provide solar wind velocity, density and interplanetary magnetic field (IMF) measurements. Time periods are utilized when Polar UVI provides a global view of the auroral distribution and at least two DMSP satellites measure particle properties, electric fields, and field-aligned currents in the upper ionosphere. Utilizing these data the understanding will be improved of the occurrence of trans-polar arcs (TPAs) and theta aurora in both hemispheres and the detailed plasma flows associated with them. In particular, the existence of high latitude TPAs is one of the most unusual features seen in the ionosphere and implies an unusual magnetospheric topology. The electrodynamics of TPAs is directly related to how coupling occurs between the solar wind-magnetosphere-ionosphere system during northward IMF. Analysis of the unique data set described will provide insight into simultaneous behavior and/or existence of TPA in both hemispheres and thus also into the topology of the magnetosphere.