Spatial Correlations between Radio Aurora and 4278 Å Aurora Intensity

In order to study the spatial relation between 50MHz-radar echoes and visual auroral forms, a photometer observing auroral emissions at 4278Å was installed at Mizuho Station during the period from July to October, 1978. Several examples of the measurements are shown to discuss qualitative differences between the radio aurora and the optical auroras. It is shown that the correlation between optical and radio aurora intensities becomes poor in highly active aurora but is generally good for quiet aurora. Phenomena are found that the radio auroral intensities become low within auroral arcs

Simultaneous Observations of Aurora with a Doppler-Radar and Sounding Rockets

A 50MHz auroral doppler-radar was operated at Syowa Station, Antarctica, in 1978 in cooperation with sounding rocket experiments during the International Magnetospheric Study. E-region irregularity-drift was measured by the radar while electric field, electron density fluctuation and other parameters were measured by the rockets. Electric field components perpendicular to the radar wave-vector, which were derived from the doppler shifts of echoes, are compared with in situ electric field measurement to find a qualitative agreement between both results. Sharp peaks due to the two-stream instability were found in echo spectra. The radar echo intensity seems to be dependent on the drift velocity of irregularities