Ground-satellite coordinated study of the April 5, 1979 events - Observation of O(+) cyclotron waves
Abstract
In a period of particularly large magnetospheric disturbance, large amplitude pc2 waves were observed in the late dawn sector on GEOS-2 and in the vicinity of the foot-point of the satellite's field line. The waves have dominantly left-hand polarization and their frequency is closely correlated to the O(+) gyrofrequency in the magnetosphere. After the start of the pc2 activity, the GEOS-2 particle detectors measured an enhanced flux of energetic O(+) ions in the energy range from 0.9-16 keV. By calculating the dispersion of ion cyclotron waves in a multicomponent plasma, it is shown that the energetic O(+) ions can destabilize the observed pc2 waves.
- Publication:
-
Journal of Geophysics Zeitschrift Geophysik
- Pub Date:
- September 1984
- Bibcode:
- 1984JGZG...55..134I
- Keywords:
-
- Geomagnetic Pulsations;
- Ion Cyclotron Radiation;
- Magnetospheric Instability;
- Oxygen Ions;
- Space Plasmas;
- Atmospheric Composition;
- Flux (Rate);
- Geos 2 Satellite;
- Pitch (Inclination)