This is event is characterized by a low solar wind speed of 275 km/s, a
small positive and
only slight sign changes in the
component of the IMF during the
period. IMP8 is located in the tail region.
The
index at the time of the event was below 1.0.
A large area of backscatter has been recorded during this event from both
radars. Visible in Figure 5.64 are three
distinct regions of double-peak spectra occurrences.
One patch is centered at about E and
N, an extended band
stretches from
E and
N in a curve southeast to
E and
N and a patch is located further south, centered at
about
E and
N.
Figure 5.64: Map of spectral findings from the Saskatoon and Kapuskasing radars:
25 Feb/95
As can be seen in Figure 5.65, the track of the satellite is situated very
well for observations. It enters the south-east patch of double-peaked spectra at
about , exits at about
and reenters the extended band at
, leaving at
.
Figure 5.65: Peak-map with overlaid flight path of the DMSP F12 satellite: 25
Feb/95
Figure 5.66: Average electron energy and flux determined from SSJ/4 instrument
measurements: 25 Feb/95
It is apparent from Figure 5.66 that both periods include
satellite observations of increased flux.
The low energy precipitation begins at about with
a sharp peak.
The features are more apparent in Figure 5.67 where it can be seen that
F-layer ionization is high from about
to
and again
from
to
. Both periods correspond to regions of double-peaked
spectra seen with the radar.
Figure 5.67: Estimated ionization rates at E- and F-layer heights determined from electron
spectra measurements: 25 Feb/95
The conductance graphs of Figure 5.68 show little E-layer conductance changes.
Figure 5.68: Estimated E-layer conductivities from the Robinson model: 25 Feb/95
The velocity map of Figure 5.69 is characterized by low velocities and complex convection patterns. The regions of double-peaked spectra are present in all areas of the flow map and do not seem to correspond to a particular region.
Figure 5.69: SuperDARN velocity map: 25 Feb/95