On the connection between microbursts and nonlinear electronic structures in planetary radiation belts
- Department of Radio Science, Aalto University, FI-02150 (Finland)
- NASA Goddard Space Flight Center, Greenbelt, MD (United States)
- Space Sciences Laboratory, Berkeley, CA (United States)
Using a dynamical-system approach, we have investigated the efficiency of large-amplitude whistler waves for causing microburst precipitation in planetary radiation belts by modeling the microburst energy and particle fluxes produced as a result of nonlinear wave–particle interactions. We show that wave parameters, consistent with large-amplitude oblique whistlers, can commonly generate microbursts of electrons with hundreds of keV-energies as a result of Landau trapping. Relativistic microbursts (>1 MeV) can also be generated by a similar mechanism, but require waves with large propagation angles θ{sub kB}>50{sup ∘} and phase-speeds v{sub Φ}⩾c/9. Using our result for precipitating density and energy fluxes, we argue that holes in the distribution function of electrons near the magnetic mirror point can result in the generation of double layers and electron solitary holes consistent in scales (of the order of Debye lengths) to nonlinear structures observed in the radiation belts by the Van Allen Probes. Our results indicate a relationship between nonlinear electrostatic and electromagnetic structures in the dynamics of planetary radiation belts and their role in the cyclical production of energetic electrons (E⩾100 keV) on kinetic timescales, which is much faster than previously inferred.
- OSTI ID:
- 22882310
- Journal Information:
- Astrophysical Journal, Vol. 816, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); Since 2009, the country of publication for this journal is the UK.; ISSN 0004-637X
- Country of Publication:
- United Kingdom
- Language:
- English
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