Physics – Space Physics
Scientific paper
Dec 2007
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2007agufmsm33b1340k&link_type=abstract
American Geophysical Union, Fall Meeting 2007, abstract #SM33B-1340
Physics
Space Physics
2774 Radiation Belts, 6984 Waves In Plasma (7867), 7514 Energetic Particles (2114), 7867 Wave/Particle Interactions (2483, 6984)
Scientific paper
Whistler-mode waves that are either spontaneously generated in-situ (i.e., chorus), or externally injected (lightning, VLF transmitters) are known to be responsible for the loss of radiation belt electrons. An important determinant in the quantification of this loss is the dependence of the cyclotron resonant pitch angle scattering on the initial wave normal angles of the driving waves. Inan et al. (U.S. Inan et al., Controlled precipitation of radiation belt electrons, Journal of Geophysical Research-Space Physics, 108 (A5), 1186, doi: 10.1029/2002JA009580, 2003.) suggested that the lifetime of > 1 MeV electrons in the inner radiation belts might be moderated by in situ injection of VLF whistler mode waves at frequencies of a few kHz. The formulation of Wang and Bell (T.N.C. Wang and T.F. Bell, Radiation resisitance of a short dipole immersed in a cold magnetoionic medium, Radio Science, 4(2), 167-177, February 1969) for an electric dipole antenna located in the inner magnetosphere established that most of the radiated power is concentrated in waves whose wave normal angles lie near the local resonance cone. Such waves, compared to those injected at less oblique initial wave normal angles, undergo several more magnetospheric reflections, persist in the magnetospheric cavity for longer periods of time, and resonate with electrons of higher energies. Accordingly, such waves may be highly effective in contributing to the loss of electrons from the inner belt and slot regions [Inan et al., 2006]. Nevertheless, it has been noted (Inan et al. [2006], Inan and Bell [1991] and Albert [1999]) that > 1 MeV electrons may not be effectively scattered by waves propagating with very high wave normal angles, due to the generally reduced gyroresonant diffusion coefficients for wave normals near the resonance cone. We use the Stanford 2D VLF raytracing program to determine the energetic electron pitch angle scattering and the precipitated flux signatures that would be detected for a range of initial wave normal angles. We conclude that whistler-mode waves with highly oblique wave normal angles may be more effective than previously believed at precipitating > 1 MeV electrons, despite the dependence of the scattering coefficients on wave normal direction.
Bell Timothy F.
Bortnik Jacob
Inan Umran S.
Kulkarni Pradeep
No associations
LandOfFree
Dependence of Whistler-mode Wave Induced Electron Precipitation on k-vector Direction. does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Dependence of Whistler-mode Wave Induced Electron Precipitation on k-vector Direction., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dependence of Whistler-mode Wave Induced Electron Precipitation on k-vector Direction. will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1424515