Multiple plasmapause undulations observed by the IMAGE satellite on 20 March 2001

We report global plasmasphere imaging observations from 20 March 2001 that show four main undulatory ripples propagating along the duskside plasmapause at an average westward azimuthal speed of 5 km/s. The aurora during this event showed some degree of temporal and spatial (both MLT and L-shell) correlation with the undulations, but this correlation was not nearly as strong as for a previous undulation event on 17 April 2001. Auroral intensifications preceded or coincided with the inception of all plasmapause indentations and undulations. However, there were several auroral enhancements at various latitudes that do not appear to have strong UT or MLT correlation with plasmapause motions. Auroral signatures that mapped closest to the L and MLT of the plasmapause were associated with the strongest, most long-lived plasmapause undulations, implying that magnetotail disturbances at lower L were more effective at distorting the plasmapause. Solar-wind-driven convection was strong, but relatively steady during the plasmapause undulations, and does not appear to have been directly responsible for them. This strong convection was apparently modulated by disturbances in the magnetotail that produced both the auroral signatures and the transient plasmapause distortions.