Oscillatory Nature of the Magnetosphere III. Resonance Oscillations. Some Simulation

The characteristics of the Fourier spectral frequency maxima Fs, max in the frequency band (F = 7-50) MHz which compose the extra low frequency e.m. waves-so called Pc2-Pc5 micropulsations, created in the magnetosphere are considered in this paper. It should be considered as an extended part of the data analysis presented in paper II (Alpert et al., 1995). The obtained characteristics of the spectra are compared with spectra of signals which can simulate the shapes of the envelopes of the examined records of the unfiltered magnetic field B(t). They are also confronted with spectral frequency maxima of different signals and with resonance frequencies of different resonators. This analysis confirms our conclusion that the found spectral maxima can be resonance frequencies-eigenvalues of a magnetospheric oscillating system. The resonance swinging of the background plasma oscillations, which creates strong packets of waves is also simulated by simple calculations. The variety, of shapes of the filtered packets of waves as observed in the magnetosphere is obtained by these calculations.