Paired electrostatic shocks

Examination of 21 paired electrostatic shocks from a portion of the S3‐3 satellite data set has shown that in 20 cases the electric field in the equatorward half of the paired shock pointed poleward while the electric field in the poleward half of the paired shock pointed equatorward. At the same time the electron, ion, and wave data indicated the presence of an electric field parallel to the magnetic field in the region between the paired shocks. This parallel electric field was at an altitude below that of the satellite and pointed out of the ionosphere so as to accelerate ions upward. A comparison of the potential across the electrostatic shock and the energy of the corresponding ion beam at the energy of maximum flux gives reasonable agreement. This provides convincing evidence that the potential contours associated with paired electrostatic shocks close across the magnetic field to produce the auroral electron acceleration responsible for inverted‐V particle distributions and auroral arcs.