Comparison of properties of upstream whistlers at different planets
Abstract
Whistler mode waves have been recorded in the upstream region of Mercury, Venus, Earth and Saturn. They are elliptically polarized and observed typically at frequencies between 0.1 to 4 Hz. These intrinsically right handed waves can be left-hand polarized in the spacecraft frame as a result of strong negative Doppler shift. The waves propagate at an angle between 10 and 60 deg to the background magnetic field, with DeltaB/B rarely exceeding 0.1. Comprehensive studies of these waves at Earth and Venus indicate that upstream whistlers are generated at the shock rather than locally in the foreshock. In this paper we compare properties of upstream whistlers at all these planets. We also discuss the utilization of selected properties of these waves to evaluate the effective Alfvenic Mach number and the shock thickness at Mercury where solar wind measurements are not available.
- Publication:
-
Advances in Space Research
- Pub Date:
- August 1995
- DOI:
- 10.1016/0273-1177(95)00220-9
- Bibcode:
- 1995AdSpR..16d.137O
- Keywords:
-
- Earth (Planet);
- Mercury (Planet);
- Planetary Magnetic Fields;
- Saturn (Planet);
- Solar Wind;
- Venus (Planet);
- Whistlers;
- Doppler Effect;
- Elliptical Polarization;
- Interplanetary Magnetic Fields;
- Mach Number;
- Magnetohydrodynamic Waves;
- Shock Waves;
- Spectrum Analysis;
- Astrophysics