摘要
将北京地区地球变化磁场的水平分量作为一无规时间序列，利用谱分析方法求出了１９５９，１９６５，１９７０和１９７６年时间段的分数维布朗运动（ＦＢＭ）的维数Ｄｂ。结果表明Ｄｂ值与太阳活动性呈负相关。进而利用时间延迟方法来重建该序列在相空间的吸引子，计算得到吸引子的维数Ｄ＝４．２±０．４，最大Ｌｙａｐｕｎｏｖ指数总是正值。这表明地球变化磁场可能是混沌的。还利用一简单模型说明太阳活动性对地球变化磁场Ｄｂ值的影响。
It regarded the horizontal component of the earth's magnetic field observed in Beijing as a random time series,the FBM fractal dimension Db of the time series in 1959, 1965,1970 and 1976 was obtained by use of spectra analysis.The results show that the relation between Db and the solar activity is negative.The attractor was reconstructed by means of time delay,and the dimension of the underlaying system is 4.2±0.4.The largest Lyapunov exponent is always positive.These results indicate that the varying component of the earth's magnetic field may be chaotic.Finally, we illustrate the effect of solar activity on Db using a simple model qualitatively.
出处
《地球物理学报》
SCIE
EI
CSCD
北大核心
1995年第1期16-24,共9页
Chinese Journal of Geophysics
基金
国家自然科学基金
关键词
地球变化磁场
分形
混沌
地磁场
Varying component of the earth's magnetic field,Fractal,Chaos
