The motion and magnetic structure of the plasma sheet near 30 earth radii

Data taken by the NASA-GSFC magnetometer aboard the Explorer 34 satellite are analyzed in an effort to ascertain the average motion and magnetic field structure of the plasma sheet near 30 earth radii. It is found that the flapping motion of the plasma sheet in the solar ecliptic Z-coordinate is characterized by a typical speed of 90 km/sec and an amplitude of plus or minus 2 earth radii. Results suggest that there exists a layer of nearly uniform cross-tail current density in the central region of the plasma sheet approximately 2.3-2.6 earth radii thick within which the solar-magnetospheric X-component of the magnetic field changes from 10 gamma to -10 gamma.