Plasma Dynamics Associated with Auroral Potential Structures: A Three-Dimensional Multimoment, Multifluid Model

将开发第一个三维、多动量、多流体模型，以研究极光电离层中的等离子体传输现象及其与全球等离子体动力学的关系。极光电离层中潜在结构的形成、它们与低频波的联系以及它们与等离子体加热和加速的联系是有关电离层-磁层耦合的重要和突出的问题。为了研究这些过程，我们将推广我们现有的一维（1D）多动量，多流体输运模型？Granguli等人，1988年通过调整现有的3D传输代码来实现三维的？Guzdar等人，1992！拟议的3D代码将保留我们的1D模型的广泛的磁场对齐的动力学。三维流体方程允许一类低频流体不稳定性和相关的跨场输运被同时处理。这些低频不稳定性对极光过程的影响，如潜在结构的形成，可能是重要的，但仍然没有探索。跨场输运可以显著地缓和1D或2D模型的结论。由于运输是自洽产生的等离子体流体不稳定性，一个统一的图片，包括不稳定性和运输过程需要一个三维制剂。我们将使用三维模式来研究（1）极光势结构的自洽产生和（2）相关的极光加速过程，包括由于动力学不稳定性引起的等离子体加热。相关动力学不稳定性（如静电离子回旋不稳定性）的宏观效应将通过异常碰撞项纳入我们的3D模型中，就像我们的1D模型一样。理论建模工作将与J.L.博士的实验计划同步进行。伯奇，西南研究所和博士T. E。摩尔，NASA/MSFC。

The first three-dimensional, multimoment, mulifluid model will be developed to study plasma transport phenomena in the auroral ionosphere and their relation to global plasma dynamics. The formation of potential structures in the auroral ionosphere, their connection to low-frequency waves and their association with plasma heating and acceleration are important and outstanding issues concerning Ionosphere-Magnetosphere coupling. To investigate these processes we will generalize our existing one-dimensional (1D) multimoment, multifluid transport model ?Granguli et al., 1988! to three-dimensions by adapting an existing 3D transport code ?Guzdar et al., 1992!. The proposed 3D code will preserve the extensive magnetic field-aligned dynamics of our 1D model. The 3D fluid equations permit a class of low-frequency fluid instabilities and the associated cross-field transport to be treated simultaneously. The consequences of these low-frequency instabilities on auroral processes, such as the formation of potential structures, could be significant but remain unexplored as yet. The cross-field transport can substantially moderate the conclusions of 1D or 2D models. Since the transport is self-consistently generated by plasma fluid instabilities, a unified picture that incorporates both the instability and transport processes requires a 3D formulation. We will use the 3D model to investigate (1) self- consistent generation of auroral potential structures and (2) the associated auroral acceleration processes including plasma heating due to kinetic instabilities. The macroscopic effects of relevant kinetic instabilities (such as the electrostatic ion cyclotron instability) will be incorporated into our 3D model via anomalous collision terms, as was done in our 1D model. The theoretical modeling effort will proceed in tandem with the experimental programs of Dr. J.L. Burch, Southwest Research Institute and Dr. T.E. Moore, NASA/MSFC.