DETERMINATION OF IONOSPHERIC CONDUCTIVITIES FROM FUV AURORAL EMISSIONS

The purpose of this paper is to examine the viability of using LBH emission ratios to infer amoral conductances and to quantify the strengths and weaknesses of this technique. We show that column-integrated Hall and Pedersen conductances may be determined from a single remote measurement of a pair of amoral LBH emissions, one in the region of strong O-2 absorption (1464 Angstrom) and one lying outside of this region (1838 Angstrom). The dependence of the determined conductivities on incident average energy, total energy flux, and changes in solar and magnetic activity levels is examined. We show that, for energies above 5 keV, amoral conductances may be scaled by the square root of the incident energy flux with errors less than about 20%. For lower energies, however, the scaling may deviate significantly from a power of 0.5. We provide appropriate scaling factors as a function of average energy. We also note that the choice of either a Gaussian or Maxwellian distribution can significantly affect low-energy (<1 keV) conductance calculations. Finally, we quantify the conditions under which the mean energy of a Gaussian energy distribution may differ significantly from the characteristic energy.