北京地区磁暴频谱及能量的分配因子

本文利用北京、青光、昌黎地磁台1973-1977年80个磁暴资料,借助快速付里叶变换的方法,把时间域里的磁暴转化到频率域中,以频谱的形式表现出来,用频率为参量把不同类型的磁暴进行了相互间的比较和分析;研究了磁暴在频率域中的特性.得出了局部地区磁暴频谱的一般特征;并发现在周期0.5-6.8小时范围内,磁暴能量具有恒定的分配因子.这对探讨磁暴源的物理特性以及日地关系的研究都是有意义的. 

The Frequency Spectra and the Energy Distribution Factor of Magnetic Storm at Beijing Areas

In this paper, 80 magnetic storms during 1973-1977 are analyzed by means of the Fast Fourier Transform (FFT). The data were selected from the three observatories of Beijing, Qing Guang and Chang Li.It is get the general nature of the magnetic storm spectral components by the dispersion formula of FFTin some local areas. It is find the spectral features are nearly the same at the three observatories. The storm spectral amplitude decreases with increasing frequenecy and are linear in the logarithmic coordinate. This linear trend is obvious especially for the period range from 0.5 hours to 6.8 hours.It is calculated the spectral slopes b in this period range by means of the weighted least square fitting method, and the storm energy utilizing the parsval energy equation. All the spectral slopes of magnetic storm are close to each other. So the energy partitioning law for frequency of storm spectra is consistent.The above result is of value to a further study of the physical mechanism of magnetic storms, the physical nature of storm source, and the solar-terrestical relationship.