A Nike‐Tomahawk rocket was instrumented with a vector magnetometer and an array of particle detectors including an electron and proton energy spectrometer covering the energy range 0.5–20 keV in seven fixed intervals and measuring the pitch angle distribution from 0° to 180° as the rocket spun. The payload was launched from Poker Flat, Alaska, at 0722 UT on February 25, 1972, over a bright auroral band that evidently was the poleward electron aurora, beyond the trapping boundary. An upper limit to the measured proton flux was 106/cm² s sr keV. The energy spectrum of the electron flux measured during passage over the visible aurora always exhibited a peak within the measured energy range. During passage over the brighter auroral forms the peak shifted from ∼3 to ∼10 keV, the pitch angle distribution became peaked along B, and the intensity increased. Maximum fluxes of ∼3 × 108 el/cm² s sr keV were seen over the aurora, which reached ∼60 kR of λ5577. The electron flux in regions of maximum flux tended to be the most field‐aligned in the energy interval showing the highest intensity.

A rocket‐borne experiment containing a vector magnetometer and a set of charged‐particle detectors was launched from Poker Flat, Alaska, at 2217 LT on February 13, 1971, over a single auroral arc. Particle data in the energy range 0.5–20 kev, obtained during part of the flight, show a peak incident flux of 4 × 107 el/cm2 sec ster kev in the energy range 1–2 kev. The pitch angle distributions of these precipitating electrons were found to be fairly isotropic from 0° to 60° and to decrease from 60° to 90°. The results of the vector magnetometer indicate the existence of a system of Birkeland currents with magnitudes of 5 × 10−6 amp/m2 in the vicinity of the auroral arc. Two different models that fit the data are discussed. In both of these models the current carried by precipitating electrons opposed the net downward current measured by the magnetometer in the same region, this region being located south of that containing the peak auroral luminosity. The net upward current measured by the magnetometer flowed somewhat north of the peak auroral luminosity.