GLOBAL CONVECTION. “The solar wind electric field drives a global convection pattern in the ionosphere, which produces convection electrojets carried by drift currents flowing eastward on the duskside and westward on the dawnside of the ionosphere. Consequently, the plasma flows from the dayside toward the nightside over the polar cap, returning to the dayside along the lower latitudes, consistent with the Dungey cycle.”
https://link.springer.com/article/10.12942/lrsp-2007-1