The incoherent scatter radar at Chatanika, Alaska, has been used to study electric fields and horizontal currents associated with auroral arcs. Examples are given of arcs observed at three local times: in the evening, at the time of the midnight reversal of the north-south electric field, and in the early morning. Within the arcs the observed electric field is decreased in the early evening case and increased in the morning case. In all three examples there is a southward polarization field within the arc. The direction of this field is determined by the direction of the east-west field, which, in all three cases, is westward within the arc. The northward field variations are an ionospheric response to the increased conductivities, whereas the data indicate that the westward field variations originate above the region of enhanced conductivities. In one case it is found that the westward field behavior is correlated with the low-energy electron precipitation. The electric field variations influence the amplitude and the direction of the electrojet current. Outside the arc the current flows parallel to the alignment: inside the arc the current flows almost perpendicular to the arc alignment. In addition, upward-flowing field-aligned currents are found to exist within the arc.