Initial results on the correlation between the magnetic and electric fields observed from the DE‐2 satellite in the field‐aligned current regions

Abstract

Initial results of the electric and magnetic field observations from the DE‐2 satellite show a remarkably good correlation between the north‐south component of the electric field and the east‐west component of the magnetic field in many passes of the field‐aligned current regions. For a dayside cusp pass on August 15, 1981 the coefficient of correlation between these components was 0.996. A preliminary inspection of the available data from the first 6 months of the DE operation indicates that the similarity between the electric and magnetic field signatures of the field‐aligned currents is a commonly observed feature at all local times. We interpret this high correlation to be an indication that the closure of the field‐aligned current is essentially meridional. When the correlation between these components is not good, the closure current is likely to be flowing along the auroral belt. When the correlation between the electric and magnetic fields is high, it is possible to estimate the height‐integrated Pedersen conductivity from the observed field components.