The current distributions induced by dynamo action in a sheet of partially ionized gas moving with uniform velocity across a perpendicular magnetic field are derived for the case when the gas contains an elliptical region of greater ionization density. Special attention is paid to processes occurring away from the ends of a long narrow ellipse in which the ionization density is much greater than the surrounding region.The results are discussed in relationship to conditions pertaining in the ionosphere when a long homogeneous auroral arc is present. It is concluded that a line current, whose magnitude is linearly dependent on the height-integrated Cowling conductivity within the arc, flows along the arc.
