模糊聚类分析在耀斑-地磁扰动研究中的初步应用

PRELIMINARY APPLICATION OF FUZZY CLUSTERING IN THE FLARE-GEOMAGNETIC DISTURBANCE ANALYSES

本文运用模糊聚类分析的方法,对1975—1983年可证认出的210个耀斑-IPS激波事件进行了分析研究,给出了它们的聚类指标和模糊等价关系以及大、中、小三类耀斑-磁扰的聚类中心。初步研究结果表明:95％的耀斑-IPS激波会引起地磁扰动(∑Kp≥16);对持续1小时以上的二级耀斑和2小时以上的一级耀斑,以及多个射电源的IPS观测均出现50km/8以上的速度跳跃这类大耀斑-IPS激波事件进行模糊聚类磁扰强弱预报试验,其准确率可达80％;这种大耀斑-IPS激波事件所对应的地磁扰动变化范围很宽,从∑Kp≥12直到∑Kp≤54,这说明耀斑-激波在行星际空间的传播以及向地球的传输过程是十分复杂的。

The method of fuzzy clustering is used to study 210 geomagnetic disturbance events,which were caused by the flare associated interplanetary shock waves during the period of 1975-1983.Clustering centers,fuzzy equivalent relationships and clustering indices for three kinds of clusers (i.e.large,middle and small) are obtained.Main results are: (1) for 95 % of all flare-shock waves could cause the geomagnetic disturbances (∑Kp≥16);(2) success to failure ratio of the fuzzy-clustering prediction test is about 80% for the large geomagnetic disturbance events,which were caused by those flares with importance ≥2,lasting over hour and importance≥1,lasting over 2 hours and for those where a sudden velocity increase in the solar wind,exceeding 50km/s,were observed with at least 3 radio sources;and (3) for these large events,the variation range of the geomagnetic disturbances is very wide,from ∑Kp≥12 to ∑Kp≤54,showing that the geomagnetic effects associated with the flare-interplanetary shock waves are very complicated.