Balloon observations on the relationship of energetic electrons to visual aurora and auroral absorption

Simultaneous bremsstrahlung X-ray and photometric measurements show a rather loose correlation, in the sense of a detailed space-time association, between the appearance of X rays at balloon altitudes and visual aurora at large L values. The observations suggest that essentially different, though not infrequently coupled, mechanisms are responsible for the low and high energy portions of the precipitated electron spectrum. Detailed examination of an ionospheric absorption event associated with auroral breakup indicates that the event is largely accounted for by the same flux of low energy electrons responsible for the simultaneous luminosity enhancement.