Explorer 45 wave observations during the large magnetic storm of August 4-5, 1972
Abstract
The magnetospheric compression associated with the very large magnetic storm of August 4-5, 1972, provided an opportunity for Explorer 45 to observe plasma waves in the magnetosphere and the magnetosheath during extremely disturbed conditions. Electrostatic noise bursts were observed near the plasmapause in electric field channels from 35 Hz to 5.62 kHz. In the outer magnetosphere, electric field noise bands apparently harmonically related to the electron gyrofrequency with components as low as 3 kHz and as high as 50 kHz were observed. The electric field of the fundamental was perpendicular to B0. A mechanism including the electron cyclotron instability may generate the noise band. Hiss of 100-1000 Hz was observed in the outer magnetosphere. The electromagnetic hiss was generally weak and was observed in the magnetic wide band data only when it was strong. In the magnetosheath broad band, incoherent noise (hiss) was observed from 1 Hz to 100 kHz. This magnetosheath hiss was the strongest phenomenon observed by the plasma wave detectors during the lifetime of Explorer 45. The highest intensities of magnetosheath hiss occurred at the magnetopause. Its broad band nature suggests that magnetosheath hiss was generated locally. Broad band noise bursts and short bursts of chorus were also observed in the magnetosheath.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- January 1977
- DOI:
- 10.1029/JA082i001p00055
- Bibcode:
- 1977JGR....82...55T
- Keywords:
-
- Atmospherics;
- Explorer Satellites;
- Magnetic Storms;
- Magnetospheric Instability;
- Plasma Waves;
- Radio Frequencies;
- Electric Fields;
- Magnetic Fields;
- Magnetosheath;
- Magnetospheric Electron Density;
- Magnetospheric Proton Density;
- Propagation Modes;
- Spectral Energy Distribution;
- Wave Propagation;
- Particles and Fields-Magnetosphere: Magnetic storms;
- Particles and Fields-Magnetosphere: Magnetopause;
- Particles and Fields-Magnetosphere: Magnetosheath;
- Particles and Fields-Magnetosphere: Wave propagation