Accession Number : ADP006519

Title :   Causes and Effects of Interactions Between Energetic electrons and whistler- mode Waves in the Coupled Magnetosphere-atmosphere System,

Corporate Author : CRANFIELD INST OF TECH (UNITED KINGDOM)

Personal Author(s) : Rycroft, M. J.

Report Date : OCT 1990

Pagination or Media Count : 9

Abstract : The physical mechanism of a cyclotron resonance interaction between trapped energetic electrons and whistler-mode waves in the magnetosphere is discussed. Not only do the electrons have their pitch angles reduced in this interaction, so that they may be precipitated into the upper atmosphere, but also the waves can be amplified. Such a flux of precipitating electrons can, either by direct ionisation or via bremsstrahlung radiation, cause a pimple to be produced on the bottom of the ionosphere. That can significantly modify the amplitude and/or phase of very Low frequency radio signals propagating in the Earth-Ionosphere waveguide. Various experimental observations that demonstrate the reality of such effects are presented.

Descriptors :   *MAGNETOSPHERE, *WHISTLERS, *PRECIPITATION, AMPLITUDE, ANGLES, ATMOSPHERES, BREMSSTRAHLUNG, CYCLOTRON RESONANCE, ELECTRONS, INTERACTIONS, IONOSPHERE, PHASE, RADIATION, RADIO SIGNALS, RESONANCE, SIGNALS, UPPER ATMOSPHERE, VERY LOW FREQUENCY, WAVEGUIDES.

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE