A self-consistent field line resonance problem in the model of an axisymmetric dipole-like magnetosphere is solved. The spatial structure not only of resonance Alfven waves but also of the magnetosonic wave exciting them was obtained in this paper. The field structure of the magnetosonic wave has been determined both inside the magnetospheric cavity and in the solar wind region near the magnetosphere. This made it possible to compare the amplitudes of magnetosonic waves incident from the solar wind on the magnetosphere and the resonance Alfven oscillations which they excite in the magnetosphere. It is shown that as magnetosonic oscillations penetrate deep into the magnetosphere, their amplitude decreases several orders of magnitude. The amplitude of Alfven oscillations excited inside the magnetosphere is comparable with that of magnetosonic waves in the solar wind region. The amplitude of resonance Alfven oscillations on internal magnetic shells is significantly larger than that of resonance oscillations excited in the transition layer of the magnetosphere. ¿ 2001 American Geophysical Union |