Plasmaspheric Shoulders Seen in the Global Euv Images and Its Relation to the Overshielding Electric Field Identified By Ground-Based Magnetometers

Abstract:

We have investigated plasmaspheric EUV images and ground-based magnetic field measurements to understand the formation of the plasmaspheric shoulder. By surveying the all the EUV image of plasmasphere, we have identified the 13 plasmaspheric shoulders. 12 of them were coincident with overshielding identified by magnetic field measurement and emerged in the dawnside. It is most likely that overshielding builds up the plasmaspheric shoulders, as predicted by Goldstein et al. [2002, 2003].