GEM: Study of Magnetic Storms and Their Relation to Substorms

地球的环电流是伴随磁暴而来的巨大磁扰动的主要驱动力。磁性指数DST用来测量环电流的强度。众所周知，磁亚暴将粒子注入环电流系统，通常认为主要的磁暴也涉及同样的过程。然而，最近的研究表明，磁暴期间环电流的增长和衰减可能是由太阳风控制的直接驱动现象。这项研究将使用每小时DST测量及其与太阳风电场的相关性来调查有多少环电流是由太阳风直接驱动的。将使用一个涵盖4个以上太阳周期(44年)的DST测量数据库来建立DST和太阳风电场之间的统计关联。此外，还将使用模拟程序对具体事件进行详细研究，该程序将校正磁层顶变化的动压、亚暴电流楔形和部分环电流的影响

The Earth's ring current is the primary driver of the large magnetic perturbations that accompany a magnetic storm. The magnetic index Dst is used to measure the intensity of the ring current. It is known that magnetic substorms inject particles into the ring current system and it is usually assumed that the same process is involved with the major magnetic storms. Recent work has suggested, however, that the growth and decay of the ring current during magnetic storms may be a directly driven phenomenon controlled by the solar wind. This study will use hourly Dst measurements and their correlation to the solar wind electric field to investigate how much of the ring current is directly driven by the solar wind. A database of Dst measurements covering more than 4 solar cycles (44 years) will be used to establish statistical correlations between Dst and the solar wind electric field. In addition, specific events will be studied in detail by using a modeling procedure which will correct for the effects of variable dynamic pressure at the magnetopause, the existence of a substorm current wedge and a partial ring current