辐射带高能电子通量波动与地磁暴警报

地球磁场捕获带电粒子形成辐射带,地磁场的扰动将导致带电粒子通量的变化.根据磁暴期间外辐射带高能电子通量起伏和波动的特点及规律,利用GOES卫星实时发布的5min分辨率高能电子微分通量数据,构建了高能电子通量波动指数,并分析了该指数与地磁活动的关系.结果表明,所提出的高能电子通量波动指数与地磁事件有很好的相关性,能起到地磁暴发生的指示剂作用,相对于目前空间环境业务化预报过程中广泛使用的3hKp指数,高能电子通量波动指数能更早地警报地磁暴的发生,是潜在有效的地磁暴警报辅助手段,能为空间环境预报中的地磁暴实时警报提供重要参考. 

Fluctuations of High-energy Electron Fluxes in Earth's Radiation Belt and its Applications for Geomagnetic Storm Alert

The outer radiation belt consists mainly of high energy electrons trapped by the Earth's magnetic field. The disturbance of the geomagnetic field caused by the Coronal Mass Ejection (CME) or the Co-rotating Interaction Region (CIR) can result in electron radiation belt variations. According to the variation feature of high energy electron flux in the outer radiation belt during magnetic storms, a novel index referred to as high electron flux fluctuation index was evaluated by using the 5-min resolution sampled electron flux data provided by GOES, and its correlation with geomagnetic Kp index was analyzed. It is found that high electron flux fluctuation index has a good correlation with geomagnetic Kp index, and the new index can be used as an indicator of geomagnetic storm occurrence. In comparison with 3-hour Kp index, which is wildly used in space environment operation prediction system, the suggested index in this paper can alert geomagnetic storm occurrence earlier.