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16 Jan/95, 16:45 - 16:47 UT

Shortly before the event the solar wind speed dropped from a maximum of 380 km/s to a steady value of tex2html_wrap_inline5470 throughout the event. IMF conditions remained constant before and during the event with tex2html_wrap_inline5386 and tex2html_wrap_inline5474 positive and tex2html_wrap_inline4540 negative and magnitudes below tex2html_wrap_inline5478 . IMP8 was situated within the magnetosphere. The tex2html_wrap_inline4548 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 tex2html_wrap_inline5482 N to tex2html_wrap_inline5484 N except for a gap of some tex2html_wrap_inline5486 in longitude from tex2html_wrap_inline5400 E to tex2html_wrap_inline5490 E. Even when the rules are relaxed to allow for peaks with a separation of up to tex2html_wrap_inline5286 , 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 tex2html_wrap_inline5494 to tex2html_wrap_inline5496 , 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 tex2html_wrap_inline5498 . The average energy is first low and after tex2html_wrap_inline5500 rises to about tex2html_wrap_inline5502 .

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 tex2html_wrap_inline5504 to tex2html_wrap_inline5506 , corresponding approximately to the latitudes where double-peaked spectra are found et higher and lower longitudes. The high energy electron precipitation after tex2html_wrap_inline5506 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 tex2html_wrap_inline5510 N latitude, which is approximately the position of double-peaked spectra. Also notable is a region of low, randomly-directed velocities around tex2html_wrap_inline5512 E and tex2html_wrap_inline5514 N. This is also the location of an accumulation of double-peaked spectra observations.

Figure 5.33: SuperDARN velocity map: 16 Jan/95

next up previous
Next: 26 Jan/9516:27 - Up: Morphology during a Complete Previous: 6 Jan/9517:03 -

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