Geomagnetic and radar observations indicate that the potential and convection pattern in the northern polar cap are significantly rotated clockwise with respect to the noonmidnight meridian. On the basis of simple models, some of the basic roles of the highly conductive belt (the auroral oval) on the rotation is examined. It is shown that it develops a space charge distribution along the boundaries in such a way as to rotate the potential pattern clockwise. The rotation angle is estimated as a function of the ratio of the conductivity in the auroral oval to that in the polar cap for a given set of conditions for an assumed conductivity ratio of &Sgr;H/&Sgr;p=2.0.