ИСТИНА

The results of the analysis of the characteristics of the spectra of turbulent fluctuations of the electric and magnetic fields in the plasma sheet of the Earth's magnetosphere using the publicly available data of the Magnetospheric Multiscale Mission (MMS) are presented. The data of measurements of the electric field by EDP instrument with a time resolution of 32 s-1 and the magnetic field by FGM instrument with a time resolution of 16 s-1 were used. The localization of the satellites inside the plasma sheet was fixed by the concentration and temperature of the plasma ions obtained from the data of the FPI/DIS instruments. A preliminary analysis of the shape of the fluctuation spectra in the frequency range from 10-3 Hz to 16 Hz has been carried out. The dependency of the power spectral density (PSD) on the frequency were approximated by power dependences PSD∝f^−α at frequency intervals f = 0.014–0.5, f = 0.5–1, f = 1–2, f = 2–4, f = 4–8 Hz for both electric and magnetic fields and f = 8–16 Hz for electric field only. We obtain the values of spectra indices for the electric field PSD and the magnetic field PSD. We do not observe the noticeable difference between x-, y- and z-components of fluctuations. We have not found also any correlations of the spectral indices with levels of fluctuations, solar wind parameters or geomagnetic indices at this frequency range. In contrast, at higher frequencies strong correlation between the spectral indices and the level of fluctuations is observed.