A linkage between polar patches and plasmaspheric drainage plumes



Two distinct features are shown here to follow the same convection pattern: polar ionization patches and plasmaspheric drainage plumes. In this study, the enhanced ionospheric electron concentration, observed from Millstone Hill incoherent scatter radar, is mapped to the equatorial plane. The resulting trajectory there is found to coincide with the location of the draining plasmasphere as observed from a geosynchronous satellite. The result indicates that both the F-region electron concentration and the plasmaspheric drainage plume follow the newest separatrix (the boundary between open and closed drift trajectories) convecting sunward. Observations have shown that the polar patches are transported over the polar cap into the night side. Hence, we conclude that the draining plasmasphere should follow a similar trajectory transporting plasmaspheric material over the polar cap into the tail plasma sheet.