Effect of equatorial electrojet intensity on its landmark distances

From the correlations of seven landmark distances, s, of the equatorial electrojet with its peak eastward current intensity J0 and its space gradient dJ0/ds, we find that the entire electrojet current system, with its magnetic field, tends to contract; consequently, the current and magnetic field foci, as well as contours of equal current intensity or of equal magnetic field, move towards the magnetic dip equator as the electrojet intensity increases. Furthermore, for a given increase in intensity, the greater the landmark distance the greater its contraction; and for movement of unit distance, the nearer the position to the dip equator the greater the increase in intensity required. Three causes which possibly contribute to the contraction are briefly discussed.