Simultaneous observation of proton precipitation and auroral radar echoes


  • T. Hagfors,

  • R. G. Johnson,

  • R. A. Power


Satellite data on precipitating auroral particle fluxes were acquired simultaneously with ground-based observations of auroral radar echoes. Measurements on the auroral particle fluxes were in the energy range from about 0.5 to 50 kev, and the auroral radar observations were made at 23 cm with frequency spectra analysis to investigate the motion of the scattering region. The results for an afternoon event show that strong radar echoes occurred in the absence of observable electron precipitation but were in close time and spatial coincidence with proton precipitation, although the proton contribution to the ionization at the scattering height at 112 km was computed to be negligible compared with the solar ionization. The frequency spectra of the auroral radar echoes were not of the character expected from a two-stream instability.