In this paper we present the first high‐resolution E region neutral wind measurements made at the Chatanika, Alaska, incoherent scatter radar facility. The high‐resolution (∼10 km) measurements are made possible by a new digital correlator system that is now fully operational. Daytime measurements show that the neutral transport in the low E region follows the general pattern of the global pressure‐driven winds. However, above 110 km there is evidence that the neutral winds are being influenced by electric fields associated with daytime precipitation events. Data taken during a moderately disturbed nighttime period show an equatorward neutral wind component above ∼115 km during the evening eastward electrojet and a poleward component through the morning westward electrojet. In our analysis we have emphasized the critical dependence of the neutral wind estimates on the collision rate parameter, particularly above ∼120 km, where ion‐neutral collisions rapidly diminish.

F region ion temperature measurements were made by the Chatanika and Millstone Hill incoherent scatter radars as part of the Magnetosphere‐Ionosphere‐Thermosphere Radar Studies program of coordinated high‐latitude observations. At both radars, periods of enhanced ion temperature associated with Joule heating events were detected. A regular feature of the observations was the existence of larger and longer lasting temperature enhancements in the morning sector as contrasted with the evening sector during periods of comparable electric field magnitudes. Because the ion temperature increases in proportion to the square of the vector difference between the ion and neutral velocities, the morning/evening temperature enhancement asymmetry implies a morning/evening neutral wind asymmetry. The neutral wind in the evening must be more closely aligned to the ion flow vector. This might arise as a consequence of the higher plasma density in the evening sector, enabling the ions to set the neutral air in motion. Comparison of the simultaneous plasma density and ion velocity measurements with the ion temperature data supports the foregoing explanation for the observed greater morning sector temperature enhancements.

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The incoherent scatter radar at Chatanika, Alaska, has been used to study electric fields and horizontal currents associated with auroral arcs. Examples are given of arcs observed at three local times: in the evening, at the time of the midnight reversal of the north‐south electric field, and in the early morning. Within the arcs the observed electric field is decreased in the early evening case and increased in the morning case. In all three examples there is a southward polarization field within the arc. The direction of this field is determined by the direction of the east‐west field, which, in all three cases, is westward within the arc. The northward field variations are an ionospheric response to the increased conductivities, whereas the data indicate that the westward field variations originate above the region of enhanced conductivities. In one case it is found that the westward field behavior is correlated with the low‐energy electron precipitation. The electric field variations influence the amplitude and the direction of the electrojet current. Outside the arc the current flows parallel to the arc alignment; inside the arc the current flows almost perpendicular to the arc alignment. In addition, upward‐flowing field‐aligned currents are found to exist within the arc.

The Chatanika, Alaska, incoherent scatter radar has been used to measure the spatial variation of auroral ionization. A two-dimensional (altitude, latitude) cross-sectional map of electron densities in the ionosphere is produced by scanning in the geomagnetic meridian plane. The altitude variation of ionization is used to infer the differential energy distribution of the incident auroral electrons. The latitudinal variation of this energy distribution and the total energy input are obtained by use of the meridian-scanning technique. Examples are shown of observations made during an active aurora.