Calculation of auroral emissions from measured electron precipitation: Comparison with observation

Auroral electron flux measurements obtained with rocket-borne detectors have been used to model ionospheric effects and resulting optical radiations. The predicted emission rate of N/sub 2//sup +/ first negative group (4278 A) is in excellent accord with ground-based observations made from Fort Yukon and Ester Dome, Alaska. This measurement provides a test of the energy deposition computations and the ionization-excitation efficiency used in the model. Predictions and observations of (O I)5577 A, however, do not agree, and on the basis of the height profile of energy deposition we conclude that we do not, as yet, fully understand the low-altitude excitation or the quenching of O(/sup 1/S) in the aurora. The electron density profiles derived from the model are used to compute the ionospheric Pedersen and Hall conductivities. Ionospheric currents are deduced from vector magnetometer measurements made on board the rocket, and these are combined with the conductivities to infer the presence of an electric field orthogonal to the magnetic field of about 20 mV m/sup -1/ directed approximately 17degree west of north. (AIP)