Figure 14.

Illustration of stormtime ULF waves and their relation to ion populations incorporating results from previous and present studies. Antisymmetric waves are excited at L > 5 by energetic ions (high‐energy plasma sheet) drifting westward from the nightside injection region. Symmetric waves are excited at L < 5 in the region populated by lower‐energy ions (energized in situ population) in addition to the high‐energy plasma sheet population. In the region of overlap, the proton density (n) and temperature (T) have opposite gradients (white arrowheads). Both wave types are excited outside the plasmasphere.