Experimental verification of an S‐shaped potential structure

Abstract

S3‐3 plasma and ac‐dc electric field data are used to construct a schematic picture of electrostatic potential structures for an afternoon auroral zone transversal. The signatures impressed on the charged particle distribution functions were used to place constraints on the latitude and altitude extent of the structures, while the electric field data provided precise definition of the structures at the satellite altitude. Upflowing field‐aligned ions, ion conics, accelerated electrons, and the associated ULF‐VLF waves are located consistently with respect to the inferred potential structures. The potential distribution is found to be V‐shaped at high altitudes and S‐shaped at low altitudes.