GEM: Self-Consistent Model for Regions of Downward Auroral Current

磁层和电离层之间的主要耦合是通过沿着地球磁场流动的电流实现的。 向上的电流区通常是由向下流动的电子引起的，这已经被许多卫星观测到了。 相反，向下的电流区域通常涉及向上流动的电子，这些电子更难以观察到。 因此，我们对向下电流区域的认识落后于我们对向上电流区域的认识。 这项研究将发展一个自洽的图片等离子体和场特性的向下极光电流区域。 结果将导致更好地了解等功能，如离子锥粒子分布，向下指向的电场和ELF/VLF湍流。 这项研究的理论基础将是把这个问题分成两个独立但又相互耦合的问题，它们的时间尺度截然不同。 ELF/VLF湍流的时间尺度为毫秒，而大尺度极光流结构的演变发生在几分钟到几小时的时间尺度上。 因此，可以在缓慢演变的背景分布的上下文中确定自洽的高频频谱。

The primary coupling between the magnetosphere and the ionosphere is accomplished via electric currents flowing along the Earth's magnetic field. Upward current regions generally result from downward flowing electrons which have been observed with many satellites. In contrast, downward current regions generally involve upward flowing electrons that have been more difficult to observe. Thus our outstanding of the downward current regions has lagged behind our understanding of the upward current regions. This study will develop a self-consistent picture of the plasma and field properties of downward auroral current regions. The results will lead to a better understanding of such features as ion conic particle distributions, downward pointing electric fields and ELF/VLF turbulence. The theoretical underpinning of the study will be to break the problem into two separate but coupled problems with vastly different time scales. ELF/VLF turbulence operates on times scales of milliseconds, while the evolution of the large-scale auroral current structures takes place on time scales of minutes to hours. Thus a self-consistent high frequency spectrum can be determined in the context of a slowly evolving background distribution.