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.

The plasmaspheric plume is an important region of detached plasma elements and provides an effective coupling channel of energy/mass between the inner magnetospheric plasmasphere and outer magnetosphere. In this study, using Van Allen Probe data, we present a statistical result of plasmaspheric plumes in the inner magnetosphere, which implies that the plumes tend to occur during the recovery phase of geomagnetic storms, and the occurrence rate is larger during stronger geomagnetic activity.

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.