Excitation of magnetospheric MHD-resonator by nonstationary hydromagnetic waves of extramagnetospheric origin

The one-dimensional inhomogeneous model of medium was applied to study processes generated by nonstationary hydromagnetic waves incident on the magnetosphere from the solar wind. Particular attention was given to the case of short-term wave momentum incidence. Most energy was shown to be reflected from the magnetopause. The portion of the incident disturbance having penetrated into the magnetosphere causes excitation of the magnetospheric resonator's eigenmodes which slowly attenuate thereafter. Their attenuation results from the fact that a portion of the resonator energy is radiated through the magnetopause back to the solar wind, and another portion leaks in the vicinity of Alfvén resonance points. To each of the eigenmodes, an Alfvén resonance point corresponds that lies deep in the eigenmode opacity region. At neighborhood of this point, the disturbance is an Alfvén wave standing between magnetoconjugated ionospheres. Its energy dissipates slowly in comparison with the resonator eigenmode damping.