Balloon observations of X rays in the auroral zone: 3. High time resolution studies

During three separate balloon flights made in the auroral zone, it was found that the precipitation of energetic electrons occurred by means of short, impulsive bursts having definite features. Since these bursts were found to have no substructure, they have been called microbursts. They are homogeneous with respect to rise time and duration; the decay time is less consistent. Periodic studies of microburst spacings have revealed no strong period, but a departure from purely random behavior can be shown. Some of the characteristic times of microbursts can be explained on the basis of electron motions on the auroral zone line of force.