During the period of the event, WIND measured a solar plasma speed of 310-320 km/s and very quiet IMF conditions. The component was within 2 nT of zero and mainly negative from 15:00 to 17:00 UT. IMP8 data were not available. The index at the time of the event was 1.0 and rising.
The morphology map of Figure 5.16 shows a moderate amount of backscatter. Clearly visible is an area of missing backscatter from E to E and N to N latitude for both radars. Just beyond that region at higher latitudes double-peaks can be found in the spectrum, forming a banded region centered around N. Both radars observe the spectral features.
Figure 5.16: Map of spectral findings from the Saskatoon and Kapuskasing radars: 1 Jan/95
As indicated in Figure 5.17, the satellite passes through the region where spectral features can be seen from - and through the blank region where the radars do not detect echoes from - .
Figure 5.17: Peak-map with overlaid flight path of the DMSP F12 satellite: 1 Jan/95
The energy and fluxes shown in Figure 5.18 correlate with the radar measurements of the double peaked spectra. The flux increases past a value of at while average energies are at or below and quite variable. There is a sharp increase in both the flux and characteristic energy at , after which the average electron energy remains steady at about . The flux then drops below at while the characteristic energy remains at about until the satellite leaves the field of view of the radars.
Figure 5.18: Average electron energy and flux determined from SSJ/4 instrument measurements: 1 Jan/95
Figure 5.19 shows, as expected, a high F-layer ionization rate when there was a large flux of soft electrons with characteristic energy around . This interval corresponds exactly with the occurrence of the double-peaked spectra from to . Similarly, the high energy fluxes measured later produce a high ionization in the E-layer from to , corresponding to the region of missing backscatter in the radar data.
Figure 5.19: Estimated ionization rates at E- and F-layer heights determined from electron spectra measurements: 1 Jan/95
Figure 5.20 shows a sharp conductivity increase starting at . If the satellite speed is taken as , the sharp increase in the Pedersen conductivity corresponds to a conductivity gradient along the satellite track of , centered at .
Figure 5.20: Estimated E-layer conductivities from the Robinson model: 1 Jan/95
The velocity map for the event, as shown in Figure 5.21, indicates a relatively steady flow northward of the region where double-peaked spectra were found. In the region around E and N the flow vectors are of low velocity and variable in direction. This quasi-turbulent behaviour of the velocity vectors is consistent with the assumption that the double-peaks are caused by Kelvin-Helmholtz instability driven turbulence.
Figure 5.21: SuperDARN velocity map: 1 Jan/95