CP1 is an experiment using many different pulses and pulsecodes to probe along the fieldline overhead Tromso, so all data is altitude versus time along the field-line. There are two different powerprofiles (different pulselenghts, i.e resolution and ranges), and alternating codes covering 85-270 km with high altitude resolution Ne, Te, Ti, and Vi, and the same set of data with less resolution from a longpulse covering 140 to 600 km.
Most of the actity during this event is north of Tromso, so a field aligned experiment here is not the ideal one, but the activity level on this day could not be predicted ahead of time.
These data basically show an empty evening sky until about 2000 UT when a weak E-layer forms. This may have to do with the enhancement of the eastward electrojet north of Tromso in response to some of the eastern activations. However, definitvely the onset of the main substorm at 2145 sets precipitation going, and there was a weak high altitude E-layer forming after that, being fully developed at 2200 UT. There was even some week response in the lower F-layer, indicating a broad spectrum of soft precipitation, i.e. increased loss-cone filling on closed field lines, that means dipolarisation, which means substorm onset to North, possibly even East or West of where we are. At 2220-30 there was a clear increase of precipitation both in energy (precipitation depth) and in energy range (extended altitude of Ne), indicating a second activation much closer to Tromso. It declines fast and the remaining Ne intensifies several times, probably in accordance with auroral or electrojet intensifications to the north of EISCAT. We see not much in the other parameters, except some high altitude electron heating at the time of maximum precipitation- a known effect of low energy precipitation. All in all we are safely in the region of trapped particle precipitation. Also, there was no Ti increase at the time of onset, which would have been visible if the bright auroral forms had arrived at Tromso, because of frictional heating by an electric field at the edge of a surge.