Auroral zone conductances can be estimated from the energy flux and average energy of precipitating electrons. These estimates are based on the assumption that the conductances produced by the electrons are very similar to those produced by electrons with Maxwellian energy distributions having the same energy flux and average energy. There has been some confusion in the application of this method because for a Maxwellian the average energy is twice the characteristic energy or temperature. We present revised expressions that relate height‐integrated Hall and Pedersen conductance to the flux and average energy of a Maxwellian. We show that the accuracy of this method depends on the minimum and maximum energy within which the distribution is integrated to get the energy flux and average energy. We also confirm that the conductances produced by some of the more common auroral spectral distributions are similar to those produced by a Maxwellian with the same average energy and energy flux. The application of these results is demonstrated using precipitating electron measurements made by the Hilat satellite during a pass over Greenland.

Electron density measurements made by the Chatanika radar during times when auroral particle precipitation was absent have been used to determine the variation of E region ionization and heightintegrated ionospheric conductivity as a function of solar zenith angle and solar flux. From the Chatanika radar data taken over an entire solar cycle we habe derived the electron density as a function of aliitude between 90 and 250 km for five solar zenith angles between 45 ø and 85 ø and for four different levels of solar flux. From 16 to 40 profiles were averaged together to determine the mean values; typically, the standard deviations were less than 25% of the mean. The height-integrated conductivities computed from these profiles increase by about a factor of 2 between the lowest and highest levels of solar flux. The solar contribution to the Hall and Pedersen conductances Y'n and Y.p is well represented by Y'n = 1.5 (Sa cox ;00'5 -1.7 Zp, where Z is the solar zenith angle and Sa is the 10.7-cm solar flux. In order to determine the total conductance when other ionization sources are present the altitudedependent production rate is required. This was computed from the data by using an altitude-dependent model for the effective recombination coefficient.

In this paper we present nearly coincident Chatanika radar electron density measurements and NOAA 6 particle data for a continuous (diffuse) auroral E layer with a peak electron density of 1–2 × 105 cm−3 produced entirely by proton precipitation. The radar and particle data are analyzed using the Jasperse‐Basu transport theoretic method and the semiempirical, continuous slowing down method of Rees. Comparisons between the radar results for the electron density profile and the two theoretical results are given. We conclude that the transport theoretic method of Jasperse and Basu gives a more accurate result for the shape of the electron density profile and for the location of its peak than the semiempirical, continuous slowing down method of Rees. We also apply the transport theoretic method to derive a closed form expression for the energy deposition function and compare the transport theoretic energy deposition function with that used by Rees in order to explain the differences in the electron density profiles obtained by the two theoretical methods.

Field‐aligned currents from the Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) were combined with simultaneous and coincident observations of ionospheric conductivities made by the Poker Flat Incoherent Scatter Radar (PFISR) in Alaska for 20 geomagnetically active days. The height‐integrated conductivities (conductances) were determined from the electron densities measured by the radar between 80 and 200 km altitude. Binning and averaging the data by field‐aligned current density and magnetic local time, we find that the currents correlate with conductances in both upward and downward current regions over some magnetic local times. The strongest correlation is seen in the late evening and morning sectors, with the Hall conductances two to three times larger than the Pedersen conductances for the same values of the field‐aligned current. The observed correlations reflect the mean energy of auroral precipitation, the contributions from electrons and protons to producing enhanced conductances, and the availability of charge carriers on auroral field lines. We apply linear fitting and smoothing to the correlations to construct an empirical model for specifying auroral conductances globally from AMPERE field‐aligned current maps. The energy fluxes from precipitating particles derived from the model conductances compare well with those derived using AMPERE data combined with satellite‐based measurements of far ultraviolet emissions, suggesting the results obtained at Poker Flat may be applicable to all high latitude locations. The ability to estimate conductances from AMPERE field‐aligned current maps provides the means to develop a global conductance model for the auroral ionosphere.