Suprathermal Electron Bursts Research Articles

Satellite observations of suprathermal electron bursts

Data from the ISIS 2 satellite are used to study the spatial distribution of the suprathermal electron bursts discovered by high‐altitude sounding rockets. It is found that the bursts form an integral part of the boundary plasma sheet and are linked with the formation of discrete auroral arcs. The maximum energy of the bursts is always below the peak energy in neighboring discrete forms, and it appears that if the bursts fail to reach the minimum energy found to be necessary to sustain a discrete arc they collapse within a few seconds. It is suggested that in a pass across the auroral oval the overall envelope of the maximum energy in bursts and the peak energy in discrete auroral forms reflects the variation of the available acceleration (perhaps a parallel electric potential) across the auroral oval while the energy structure in individual forms is a function of the nonlinear processes which sustain them. This explanation appears to resolve the apparent discrepancy in scale thickness between rocket and satellite inverted V's.

Magnetospheric waves measured on high altitude skylark rockets SL 1423 and SL 1424

Wave receivers were included in the payload of Skylark 12 rockets SL 1423 and SL 1424 which were launched from the Andoya Rocket Range in northern Norway as part of the U.K. I.M.S. High Latitude Campaign. These rockets were launched at 21 hrs 59 min 00 s. on October 13th 1977 and at 04 hrs 14 min 22 s. UT on 10th November 1978 and reached apogees of 788 and 796 km respectively. For the latter rocket there was an extensive network of ground-based goniometer V.L.F. receivers and it was launched at a time when Geos II was approximately on the same field line. Frequency/time spectrograms are presented for various E.L.F./V.L.F. phenomena including chorus, hiss, and lower hybrid resonance noise. Simultaneous measurements at magnetically conjugate positions gives information on the magnetospheric propagation. Comparison of bursts of hiss with data from suprathermal particle detectors which show associated bursts of electrons may provide a significant insight into the formation of suprathermal electron bursts.