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18 Feb/95, 1:25 - 1:27 UT

Elevated solar wind speeds of 420 to 430 km/s were measured by the WIND satellite. During the time of the event, the tex2html_wrap_inline4540 component of the IMF changed from a negative to positive from value while tex2html_wrap_inline5474 remained positive and tex2html_wrap_inline5386 small. No data was recorded from IMP8. The tex2html_wrap_inline4548 index at the time of the event was 1.0.

The overview map in Figure 5.46 shows extended backscatter and some double-peaked spectra scattered at low and high latitudes. There appear to be two bands of double-peaked spectra. An area of missing backscatter is centered around tex2html_wrap_inline5626 E and tex2html_wrap_inline5326 N.

Figure 5.46: Map of spectral findings from the Saskatoon and Kapuskasing radars: 18 Feb/95

Figure 5.47 shows a flight path that takes the satellite through the region of missing scatter tex2html_wrap_inline5630 to tex2html_wrap_inline5632 . At tex2html_wrap_inline5634 the satellite is located at tex2html_wrap_inline5636 N latitude where the Saskatoon radar observed double-peaked spectra along 3 beams.

Figure 5.47: Peak-map with overlaid flight path of the DMSP F12 satellite: 18 Feb/95

The energy and flux data presented in Figure 5.48 show a low flux after tex2html_wrap_inline5638 and only three low energy precipitation events at tex2html_wrap_inline5640 , 5135 s and tex2html_wrap_inline5644 . The low energy precipitation apparently produces no corresponding double-peaked spectra observations from the radar.

Figure 5.48: Average electron energy and flux determined from SSJ/4 instrument measurements: 18 Feb/95

The ionization rates in Figure 5.49 reflect the low energy precipitation events and also show some ionization at F-layer heights at tex2html_wrap_inline5646 when the satellite is about at tex2html_wrap_inline5648 N latitude. The E-layer is quiet, which can also be seen from the low conductivities in Figure 5.50.

Figure 5.49: Estimated ionization rates at E- and F-layer heights determined from electron spectra measurements: 18 Feb/95

Figure 5.50: Estimated E-layer conductivities from the Robinson model: 18 Feb/95

The velocity map in Figure 5.51 shows only a small patch of flow vectors. This is due to the fact that there was a significant amount of groundscatter, and the processing of radar data into ionospheric velocity maps involves removing groundscatter points.

Figure 5.51: SuperDARN velocity map: 18 Feb/95

next up previous
Next: 20 Feb/9516:32 - Up: Morphology during a Complete Previous: 28 Jan/952:13 -

Andreas Schiffler
Wed Oct 9 10:05:17 CST 1996