Electron-Acoustic Compressive Soliton and Electron Density Hole in Aurora

Electron-acoustic solitary waves have been studied in an electron-beam plasma system. It is found that the solution of compressive soliton only exists within a limited range of soliton velocity around the electron beam velocity. A compressive electron-acoustic soliton always accompanies with a cold electron density hole. This theoretical model is used to explain the‘fast solitary wave’event observed by the FAST satellite in the mid-altitude auroral zone.