The S3-2 and S3-3 satellites were launched into orbits with identical inclinations but with apogees of 1500 and 8000 km, respectively. Both satellites were equipped to measure magnetic fields, electric fields, and energetic electrons. By comparing a few cases when the satellites were crossing the auroral zone at approximately the same universal time and location, altitude variations in the electrodynamics of the auroral zone can be separated from universal and local time variations. Such comparisons show that there are times when the field-aligned current per unit of flux in the auroral zone measured by magnetic field deflections at the two satellites is the same at both altitudes. There are also times when the field-aligned current per unit of flux is larger at high altitudes than at low altitudes. This requires flow of currents perpendicular to the magnetic field. Comparisons of the convection electric field (scale size >0.1¿) at the two altitudes show that the electric field does not always map as though field lines were equipotentials. In addition, intense, small-scale (<0.1¿) electric fields perpendicular to the magnetic field, previously associated with electrostatic shocks, which are observed at high altitudes are usually not seen in simultaneous low-altitude observations. Only in one of the six passes was there a simultaneous observation of a region of intense, small-scale electric field variation at 800 and 1000 km.