auroral electrojet

The auroral electrojet is a powerful electric current that flows in the Earth's ionosphere, specifically in the high-latitude regions associated with auroras and magnetic disturbances. These currents are part of a larger system driven by the transfer of momentum from the solar wind, which compresses Earth's magnetic field.12

The auroral electrojets are typically observed as two broad sheets of electric current flowing from noon towards midnight in the northern and southern auroral ovals. The current on the dawn side flows westward, causing a decrease in the magnetic field on the surface, while the dusk-side current flows eastward, producing an increase. These currents occur at altitudes of about 120 kilometers in the ionosphere's E region, where collisions between ions and neutral particles are significant, leading to the generation of electric currents. The energy for these currents ultimately originates from the Sun and is propagated through space by the solar wind.34