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利用Cluster C1,GOES10,12和Polar四颗卫星的观测数据,研究了在2003年10月31日21:00～23:00 UT磁暴恢复相期间,地球磁层内大尺度ULF波的全球分布特征.数据分析结果表明,位于磁层不同区域的卫星观测到的ULF波的幅度、周期等性质差别很大.对ULF波幅度的全球分布来说,ClusterC1观测到的环向模最强,这可以解释为Cluster C1所在区域内发生了磁力线共振:空腔共振的压缩波模将能量耦合传递给磁力线共振的剪切阿尔芬波,从而观测到了到的很强的环向模.对ULF波周期的全球分布来说,ClusterC1观测到的波的频谱峰值周期最短,同步轨道高度的GOES卫星观测到的峰值周期较长,而位于更远处的Polar卫星观测到的峰值周期最长.Cluster C1在L=11.7～5.3范围内观测到环向模的周期几乎相同.GOES10和Cluster C1的三种波模的平方小波相关分析表明磁力线共振区域在向日面磁层至少扩展了四个地方时的宽度范围.Polar卫星观测的环向模是驻波,而极向模是行波,这可能是开放的磁尾波导模作用的结果.由于在时段内的太阳风速度很高而动压变化不明显,因此推测观测到的ULF波是高速太阳风在磁层顶激发的Kelvin-Helmholtz不稳定性激发的.
Using the data of Cluster C1, GOES10, 12 and Polar four satellites, the global distribution characteristics of large-scale ULF waves in the Earth’s magnetosphere during the period of UT magnetic storm recovery from 21:00 to 23:00 UT on October 31, 2003 The results of data analysis show that the magnitude and period of ULF waves observed by satellites located in different regions of the magnetosphere vary greatly, and for the global distribution of ULF wave amplitudes, the observed cluster modulus of ClusterC1 is the strongest, It is explained that magnetic field line resonance occurs in the region where Cluster C1 is located: the cavity mode resonance compression wave mode transmits the energy coupling to the shear-line Alfven waves resonating with the magnetic field lines, and thus a strong ring-shaped mode is observed. Globally distributed, ClusterC1 observes the shortest peak period of the spectrum of the wave, GOES satellite at the synchrotron orbit has a longer peak period, while the Polar satellite farther away has the longest peak period observed. = 11.7 to 5.3 The square wave correlation analysis of the three modes of GOES10 and Cluster C1 shows that the resonance range of the magnetic line is wide when the magnetic layer of the magnetic field has been extended to at least four places Degree range.Polar satellite observations of the circumferential mode is the standing wave, and the polar mode is the traveling wave, which may be the result of the open magnetically guided wave guide mode.As the solar wind velocity in the period of high dynamic pressure does not change significantly Therefore, it is speculated that the observed ULF wave is excited by the Kelvin-Helmholtz instability of the high-speed solar wind excited at the top of the magnetosphere.