Outer zone electron precipitation produced by a VLF transmitter
Abstract
By means of high-resolution pitch angle measurements made by a magnetic-focusing electron spectrometer on the S3-3 satellite while in the drift loss cone region of the magnetosphere, characteristics of fluxes of 108- to 654-keV electron precipitated in the inner zone, in the slot region, and in the outer zone of the magnetosphere are all shown to be consistent with the precipitation's having been produced by the same ground-based VLF transmitter, UMS. Pitch angle measurements are used to locate the longitude of precipitation. The temporal pattern of transmitter operation obtained from synoptic data from a ground-based VLF receiver is used along with drift rate calculations to predict the electron energies as a function of L shell which should be observable by the S3-3 instrument. The predicted energy response is then compared with the in situ observations, getting complete agreement. Finally, wave-particle resonance calculations are made for each of the three regions. The study indicates that ground-based VLF transmitters, which have previously been shown to produce precipitation in the inner zone and slot regions, are almost certainly instrumental in precipitating electrons in the outer zone also.
- Publication:
-
Journal of Geophysical Research
- Pub Date:
- March 1988
- DOI:
- 10.1029/JA093iA03p01849
- Bibcode:
- 1988JGR....93.1849V
- Keywords:
-
- Electron Precipitation;
- Magnetospheric Electron Density;
- Outer Radiation Belt;
- Very Low Frequencies;
- Magnetospheric Instability;
- Satellite Sounding;
- Transmitters;
- Vlf Emission Recorders;
- Magnetospheric Physics: Energetic particles;
- precipitating;
- Space Plasma Physics: Wave/particle interactions;
- Ionosphere: Wave/particle interactions