1997年1月7日至11日广州站宇宙线强度变化特征的小波分析

WAVELET ANALYSIS OF THE COSMIC RAY INTENSITIES AT GUANGZHOU MUON STATION DURING JANUARY 7-11, 1997

1997年 1月 6日爆发的日冕物质抛射 (CME)到达地球时引起了强烈的地球物理效应 ,CME在行星际空间传播时 ,广州的多方向 μ介子望远镜观测到银河宇宙线强度的变化 .本文采用小波分析方法分析了磁暴前后广州台宇宙线强度的频谱变化特征 ,结果表明 ,在磁暴前宇宙线周期为 16～ 32h的信号发生了较明显的变化 ,其中周期为 2 4～ 32h的周期特征过去没有被报道过 .广州台垂直方向宇宙线强度的谱在磁暴发生前 4 8h就出现明显的变化 ,比各向异性分析方法得到的时间提前量更大 .同时还分析了几个方向宇宙线强度的最强信号以及达到最大值的时间 ,并进行了简要的分析与讨论 .

Using wavelet analysis method, the cosmic ray intensity data observed at the Guangzhou muon station during the period from Jan. 7 to Jan. 11, 1997 is investigated. The results show that signal with periods of 16～32h has obvious variations, of which the period feature of 24～32h has not been reported before. The spectrum of the cosmic ray intensity in vertical direction has obvious variations 48h ahead of the geomagnetic storm which has more time ahead of the geomagnetic storm than the result obtained by the anisotropy method. The strongest signal in each direction is also studied and discussed briefly.