Observation of kinetic Alfven waves excited at substorm onset
Abstract
Ground-based observations of locally confined, very intense, drifting current systems by the EISCAT magnetometer in conjunction with GEOS-2 measurments are explained in terms of kinetic Alfven waves. Particle and magnetic flux measurements on GEOS-2 indicate an excitation of the waves at the inner edge of the earthward-drifting plasma sheet by resonance mode conversion from hydromagnetic surface waves. The collapsing tail-like field configuration itself is identified as the surface wave. The comparison of theoretically deduced quantities with observational results reveals a satisfactory agreement between observations and theory.
- Publication:
-
Journal of Geophysics Zeitschrift Geophysik
- Pub Date:
- August 1985
- Bibcode:
- 1985JGZG...57...65K
- Keywords:
-
- Ionospheric Disturbances;
- Magnetohydrodynamic Waves;
- Magnetospheric Instability;
- Space Plasmas;
- Eiscat Radar System (Europe);
- Geos 2 Satellite;
- Plasma Layers;
- Propagation Modes;
- Wave Excitation