【摘要】 利用 MORLET 小波变换对2000年7月13日亚暴期间地磁场变化特征进行了分析。通过小波分析可以得到亚暴增长相、膨胀相，恢复相的发展过程，探讨了亚暴期间地磁脉动的特征。从小波谱中得到，一个谱结构是处于最高纬度的 NAL 台站更早出现较大的谱值，这说明此次事件中，地磁场首先在高纬区响应行星际扰动。另一个有明显谱结构的周期在320～2000s 之间，该周期范围的波谱几乎分布一天中的各个时段，但在1000～1700 UT 亚暴期间之间频带变宽并明显增强，这表明亚暴爆发将引起地磁场在高频端的强扰动．更多还原

【Abstract】 The variations of magnetic field during the substorm on July 13,2000 were analyzed by MORLET wavelettransform.The evolution process of the substorm and the characteristics of magnetic pulsations were studied.Inwavelet spectrum,the spectrum amplitude of X component at NAL station(at the highest latitude)firstly arrivingmaximum indicated that the magnetic filed at high latitude region responses to IMF earlier.The magnetic disturbancesduring the 320～2000s period happened at whole day,but it is strongly increased at 1000～1700 UT.It representedthat the strong disturbance at high frequency band were resulted from substorm expension.更多还原