利用地面宇宙线强度变化预报地磁暴方法初步研究

分析了Nagoya宇宙线闪烁体望远镜探测数据的变化特点,定性地探讨了CME可能引起的地面宇宙线的变化特征,通过实例证实了地面宇宙线通量的异常波动是地磁暴发生的重要先兆特征,并且将8 h内宇宙线通量与该时间段内平均通量的偏差D8（t）参数应用到宇宙线数据分析中．通过数据分析与讨论,认为D8（t）参数达到一定阈值是地磁暴的重要先兆特征,但不是充分条件,虚假信号仍占多数;D8（t）参数与太阳质子事件探测结果相结合,对于大地磁暴的预报有较好的效果．

Preliminary Attempt in Prediction the Geomagnetic Storm With Ground Cosmic Ray Data

In this paper an algorithm is introduced to use the ground cosmic ray data to predict great geomagnetic storms. The muon measurement data from Nagoya station, Japan, was employed and the characters of cosmic ray evolvement before geomagnetic storm were revealed by analyzing the differences between the data just before the geomagnetic storms and the quiet days. It was found that fluctuations before geomagnetic storms increased due to the approaching of CME because the shock front and strong IMF induced by CME. An index to measure the fluctuation of data, D8(t), was used in the cosmic ray data processing. The result shows that D8(t) always increases monotonously several hours ahead the geomagnetic storm, which hopefully could become a useful factor for geomagnetic storm prediction. As it had been known that most of the large geomagnetic storms were caused by CMEs accompanying the Solar Proton Events (SPEs), the SPEs were also chosen together with D8(t) in the prediction process. The mentioned algorithm was tested with the relative data of whole year 2001. The result turned out to be encouraging with the accuracy rate reach to 80% (8 out of 10) and false rate less than 18% (2 out of 11).