Results From an RF Capacity Probe Experiment in the Auroral Ionosphere

A rocket‐borne experiment, in which measurements of the RF capacity of two spherical probes of different size were taken at several frequencies, is described. The experiment was designed to measure electron density, and was performed during an auroral disturbance. Analysis shows the data agree up to 90 km with electron density measurements by a wave‐propagation experiment. Above this height the probe data indicate the presence of field‐alined enhancements in the ionization. The characteristic “thickness” of these enhancements is ≈ 400 meters. The electron temperature could be estimated from the data, and values in excess of the neutral temperature were indicated.