EXCITATION OF MAGNETOSPHERIC MHD-RESONATOR BY STOCHASTIC HYDROMAGNETIC WAVES OF EXTRAMAGNETOSPHERIC ORIGIN
The one-dimensional inhomogeneous model of medium was applied to study the sequence of phenomena caused by stochastic hydromagnetic waves which had statistical properties of stationary white noise and were incident on the magnetosphere from the solar wind. Most of the energy of these waves was demonstrated to be reflected from the magnetopause. Waves in narrow spectral ranges near the resonator eigenfrequencies penetrate into the magnetosphere. They excite the resonator eigenmodes whose energy depends on the spectral density of an incident wave energy flux at corresponding eigenfrequencies. The energy of eigenmodes leaks through the opacity barrier in the vicinity of Alfvén resonance points (each mode has a corresponding point), where the disturbance amplitude rapidly increases, therefore the total energy localized in the vicinity of an Alfvén resonance point is much higher than that of a corresponding eigenmode. In the said vicinities, the disturbance energy dissipates due to the finite ionosphere conductivity. The dissipation power equals the incident wave energy flux penetrating into the magnetosphere.