Observations of sunward propagating waves on the magnetopause

Observations of ionospheric electric fields during an ULF resonant event are used to infer the presence of waves on or near the magnetopause propagating toward the dayside. Simultaneous satellite measurements at geosynchronous orbit confirm the presence of these surface waves. Immediately following these observations a flux transfer event appears to have occurred (Goertz et al., 1984). It is speculated that the pulsations were associated with that event.