GEM: Particle Energization and Loss Associated with Magnetospheric Compression

太阳风对地球的磁层施加压力，压力的快速变化可以在极光中产生令人惊讶的各种变化。这些变化可以通过卫星在全球范围内观测到，这些观测结果为了解磁层对太阳风驱动的响应的关键方面提供了强有力的诊断工具。最近的研究表明，等离子体片中等离子体温度的急剧变化以及等离子体片宽度的急剧变化可以在不到一小时的时间尺度上发生。这些变化反映在夜侧极光亮度的突然变化上。该项目将使用来自国防气象卫星计划（DMSP）卫星的颗粒降水数据，结合来自极地卫星的紫外线成像仪（UVI）图像数据，以及来自Geotail卫星的颗粒和波测量数据，研究太阳风动压变化的极光响应。将特别强调压力突然变化的影响。需要回答的关键科学问题是：(1)能否定量预测全球极光功率对急剧压力变化的响应；(2)磁层粒子能量和损失（通过降水）的机制是什么；(3)与这种压力事件相关的黎明/黄昏极光增强的磁层源区是什么；(4)极光椭圆和极帽对压力事件的响应时间顺序是什么？数据分析将涉及来自DMSP和Geotail卫星的大量图像和大量相应数据。这些数据将被汇编成一个数据库，并将被添加到目前由约翰霍普金斯大学应用物理实验室极光粒子和图像小组在线提供的极光数据中。

The solar wind exerts a pressure on the Earth's magnetosphere and rapid changes in the pressure can create a surprising variety of changes in the aurora. These changes can be observed on a global scale from satellites and the observations provide a powerful diagnostic tool for key aspects of the magnetospheric response to solar wind driving. Recent research has indicated that dramatic changes in the temperature of the plasma in the plasma sheet as well as dramatic changes in the width of the plasma sheet can occur on time scales of less than an hour. These changes are reflected in sudden changes in the nightside auroral luminosity. The project will use particle precipitation data from the Defense Meteorological Satellite Program (DMSP) satellites in conjunction with ultraviolet imager (UVI) image data from the Polar satellite along with particle and wave measurements from the Geotail satellite to study the auroral responses to solar wind dynamic pressure changes. Particular emphasis will be placed on the effects of abrupt pressure changes. The key scientific questions to be answered are: (1) Can the change in global auroral power in response to sharp pressure variations be predicted quantitatively, (2) what is the mechanism of magnetospheric particle energization and loss (through precipitation), (3) what are the magnetospheric source regions of the enhanced dawn/dusk aurora associated with such pressure events, and (4) what is the time sequence of auroral oval and polar cap response to pressure events?The data analysis will involve a large number of images and a large amount of the corresponding data from the DMSP and Geotail satellites. This data will be compiled into a database and will be added to the auroral data currently being served on-line by the Johns Hopkins University Applied Physics Laboratory Auroral Particles and Images Team.