Comment on the ponderomotive self-action of Alfven waves

The nonlinear equation descriptive of the ponderomotive self-action of standing Alfven waves is presented. Solutions to this equation possess a peculiar form, even though the wave amplitudes are relatively small. It is shown that the period of oscillations is diminished with a rise of amplitude. Preliminary results suggest that the heavy (light) ions are accumulated at the nodes (antinodes) of the nonlinear standing wave. It is concluded that account must be taken of the ponderomotive self-action in studies of Alfven oscillations of the magnetosphere.