Shortly before the event the solar wind speed dropped from a maximum of 380 km/s to a steady value of throughout the event. IMF conditions remained constant before and during the event with and positive and negative and magnitudes below . IMP8 was situated within the magnetosphere. The index at the time of the event was 4.0 (disturbed).
The overview in Figure 5.28 shows a localized region of double-peaked spectra from N to N except for a gap of some in longitude from E to E. Even when the rules are relaxed to allow for peaks with a separation of up to , no more events are found in this region.
Figure 5.28: Map of spectral findings from the Saskatoon and Kapuskasing radars: 16 Jan/95
As can be seen in Figure 5.29, the satellite passes through the longitudinal gap in the region of double-peaked spectra. From to , the satellite traverses the latitude range where double-peaked spectra occur to the east and west of the trajectory.
Figure 5.29: Peak-map with overlaid flight path of the DMSP F12 satellite: 16 Jan/95
Figure 5.30 shows that there was a very small flux during most of the satellite track segment, except after . The average energy is first low and after rises to about .
Figure 5.30: Average electron energy and flux determined from SSJ/4 instrument measurements: 16 Jan/95
The ionization rate data shown in Figure 5.31 yield a more revealing picture than the energy/flux data from the previous figure. Observable is an increase in F-layer ionization by two orders of magnitude from to , corresponding approximately to the latitudes where double-peaked spectra are found et higher and lower longitudes. The high energy electron precipitation after is reflected in the increased E-layer ionization rate and the E-layer conductivities that are presented in Figure 5.32.
Figure 5.31: Estimated ionization rates at E- and F-layer heights determined from electron spectra measurements: 16 Jan/95
Figure 5.32: Estimated E-layer conductivities from the Robinson model: 16 Jan/95
The velocity map in Figure 5.33 shows relatively high velocities and two segments of flow in opposite directions, the dividing line along N latitude, which is approximately the position of double-peaked spectra. Also notable is a region of low, randomly-directed velocities around E and N. This is also the location of an accumulation of double-peaked spectra observations.
Figure 5.33: SuperDARN velocity map: 16 Jan/95