The Current-Voltage Relationship in Large-scale Magnetosphere-Ionosphere Coupling

该项目解决了三个主要问题：(1)极光降水对场向电流（Birkeland电流）密度、电离层等离子体特性和EUV电离的依赖关系；(2)极光降水的分布与不同的Birkeland流的分布有什么关系；(3)与直接观察到的伯克兰海流相比，奈特关系实际上有多好？这项研究将使用的工具是稳定的伯克利电流数据库，该数据库来自铱星星座的磁力计数据。Birkeland目前的数据将与来自各种航天器的数据结合使用，包括TIMED、Polar、Cluster和DMSP。场向电流，也称为伯克兰电流，提供了磁层与电离层耦合的主要机制。了解电流系统（上行电流和下行电流）如何依赖于带电粒子降水和加速电压的细节，对于我们成功模拟磁层-电离层耦合以及能够对空间天气事件的过程产生现实预测的能力至关重要。

The project addresses three main questions: (1) What is the dependence of auroral precipitation on field-aligned current (Birkeland current) density, the ionospheric plasma properties and the EUV ionization; (2) what are the distributions of auroral precipitation associated with different distributions of Birkeland currents; and (3) how well does the Knight relationship actually compare to direct observations of the Birkeland currents? The tools to be used for this study will be the database of stable Birkeleand currents derived from the magnetometer data from the Iridium satellite constellation. The Birkeland current data will be used in combination with data from a variety of spacecraft, including TIMED, Polar, Cluster, and DMSP.Field-aligned currents, also called Birkeland currents, provide the primary mechanism by which the magnetosphere is coupled to the ionosphere. Understanding how the current systems, both upward currents and downward currents, depend on the details of the charged particle precipitation and the accelerating voltage is critical to our ability to successfully model magnetosphere-ionosphere coupling and being able to generate realistic forecasts of the processes for space weather events.