From the statistical analysis of potential plasmaspheric plume, we find that there is almost no correlation between plume width and the level of geomagnetic storm intensity. However, for plumes in the recovery phase after improved sifting, there is a negative correlation between the plume width and absolute value of minimum Dst during the storm. We suggest that the plasmaspheric particles may escape quickly during intense storms, causing plume to be relatively narrow during the recovery phase.

We report an event where hiss wave intensity decreased, associated with the enhanced convection and a substorm. We suggest that the enhanced magnetospheric electric field causes the outward and sunward motion of energetic electrons. This leads to the decrease of energetic electron fluxes on the duskside, which provide free energy for hiss amplification. The study reveals the important role of magnetospheric electric field in the variation of the energetic electron flux and hiss wave intensity.