Aurora at high latitudes of Ganymede

The aurora on Ganymede results from the interaction of Jovian plasma disk electrons with Ganymede's tenuous atmosphere. At the same time, the electrons surrounding Ganymede have energy insufficient for the excitation of emission in the observed lines. They can acquire the necessary acceleration through various processes, such as reconnection of Ganymede's intrinsic magnetic field with the Jovian magnetic field in the upstream and downstream regions. The generation mechanism of a field-aligned potential drop on auroral field lines is considered. The lack of charge carriers required for the generation of the necessary current closing the Alfv,n-wing field-aligned currents is shown to be responsible for the formation of an accelerating potential and the acceleration of thermal magnetospheric electrons. The total current in the circuit is determined by the calculated cross-field potential drop applied to Ganymede and by the Pedersen conductivity of Ganymede's ionosphere.