Testing Models for Magnetic Impulse Events

研究人员将研究日侧磁层中的磁脉冲事件（MIE）。MIE事件是等离子体进入磁层的标志。这项研究将利用地面和天基数据，这些数据将与理论模型相结合，以分离出导致这些过程的最重要机制。在第一年，研究人员将确定在高纬度地面磁图中看到的控制MIE运动的因素，并区分根据突发合并、压力脉冲和开尔文-亥姆霍兹不稳定性提出的解释。在第二年，他们将通过比较地球同步和地面特征与最近提出的几种耦合模型的预测来研究磁层-电离层耦合的本质。在第三年，他们将对卫星成像仪观测到的日光侧极光进行调查，确定它们的发生模式与太阳风条件的关系，并建立它们与先前报道的高纬度地面观测中看到的瞬变事件的关系。了解MIE对于确定控制太阳风进入磁层及其对地球电离层、热层和空间天气的后续影响的因素非常重要。

The investigators will study magnetic impulse events (MIE) in the dayside magnetosphere. MIE events are signatures of plasma entry into the magnetosphere. The study will make use of ground- and space-based data, which will be combined with theoretical models to isolate the most important mechanisms responsible for these processes. In the first year, the investigators will identify the factors controlling the motion of MIE seen in high latitude ground magnetograms and discriminate between proposed interpretations in terms of bursty merging, pressure pulses, and the Kelvin-Helmholtz instability. During the second year, they will investigate the nature of magnetosphere-ionosphere coupling by comparing geosynchronous and ground signatures with the predictions of several recent proposed coupling models. In the third year, they will undertake a survey of dayside auroral brightenings seen by satellite imagers, determine their occurrence patterns as a function of solar wind conditions, and establish their relationship to previously reported categories of transient events seen in high latitude ground observations. Understanding MIE is important for identify the factors that control solar wind entry in the magnetosphere and its subsequent effects on Earth's ionosphere and thermosphere and space weather.