As has been observed on at least Jupiter, Saturn and Earth, the atmosphere at the poles rotate in the opposite direction of the atmosphere, with aurora forming at the boundary of the rotating mass. This boundary is also where the planets magnetic field touches the suns magnetic field (the interplanetary magnetic field).

The suns magnetic field, flowing through the Earth, creates an electrical current, which can be seen as the entire mass of the atmosphere at the poles moving as that current.

Aurora are standing waves

A standing wave (black) depicted as the sum of two propagating waves traveling in opposite directions (red and blue). The boundary between the atmosphere at the poles of Earth, and the rest of the atmosphere, is a standing wave from the two opposing currents which creates an excitation field, aurora.