On Predicting VLF Triggering in the Inner Magnetosphere
Abstract
VLF waves in the magnetosphere have been observed to be amplified and cause secondary VLF waves much stronger than the initial (pump) wave. This phenomenon is termed VLF triggering. Understanding the physical processes underlying the VLF triggering is critical to predicting the effectiveness of ground or space based transmitters to stimulate the precipitation of energetic electrons. We report on initial results of a statistical study aimed at specifying geophysical conditions of VLF triggering from the Siple Station VLF transmitter. Most favorable conditions for the triggering in the morning sector seem to be satisfied after weak/moderate substorms. The triggering occurred when broad-band hiss emissions were present and the pump frequency was well above the maximum hiss-band frequency. No triggering occurred when chorus emissions were also present. These results are consistent with the formation of the step-like distribution of background energetic electrons via broad-band hiss-particle interaction inside ducts and with the second order resonance theory.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2006
- Bibcode:
- 2006AGUFMSM13B..02M
- Keywords:
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- 2471 Plasma waves and instabilities (2772);
- 2772 Plasma waves and instabilities (2471);
- 2774 Radiation belts