Solar plasma speeds as measured by WIND were very constant at 400 km/s throughout the event. IMF parameters as measured by WIND indicate a positive and a change from positive to zero during the event. IMP8 recorded a sharp drop of the and the components preceding and during the event while remained positive and small. The index at the time of the event was 2.0 and falling.
The overview in Figure 5.52 indicates good scattering conditions for both radars. The Kapuskasing radar shows a region of missing backscatter around N from E to E. Both radars record double-peaked spectra in a region centered at N from about E to E. The locations of these spectra from both radars compare well.
Figure 5.52: Map of spectral findings from the Saskatoon and Kapuskasing radars: 20 Feb/95
As can be seen in Figure 5.53, the satellite passes right through the region where double-peaked spectra were found from to . It also crosses over the region of missing Kapuskasing backscatter from to as can be seen in Figure 5.52.
Figure 5.53: Peak-map with overlaid flight path of the DMSP F12 satellite: 20 Feb/95
Figure 5.54 shows relatively high fluxes during most of the track segment. The electron energy is highest from to corresponding to the region of missing backscatter. From to , which is the interval in which double-peaked spectra were found, the satellite recorded several high flux events at low electron energy.
Figure 5.54: Average electron energy and flux determined from SSJ/4 instrument measurements: 20 Feb/95
Figure 5.55 shows clearly that the region of high F-layer ionization corresponds exactly to the period in which double-peaked spectra were observed.
Figure 5.55: Estimated ionization rates at E- and F-layer heights determined from electron spectra measurements: 20 Feb/95
Figure 5.56 indicates the beginning of high E-layer conductivity to be at about matching exactly the beginning of missing Kapuskasing backscatter.
Figure 5.56: Estimated E-layer conductivities from the Robinson model: 20 Feb/95
The velocity map in Figure 5.57 shows that there is a strong shear in the region of westward convection centered at about latitude, which is the center of the region of double peaked spectra. Below N is a section of flow at very low velocities which are in a westward direction further south. An interesting feature is the presence of a large scale, morning sector convection vortex centered at about N and E. The vortex has upward vorticity so the field-aligned current is downward which is as expected, opposite to the upward FAC observed in afternoon vortices (Bristow et al., 1995).
Figure 5.57: SuperDARN velocity map: 20 Feb/95