Chapter 10 - ELF/VLF noise-like emissions and electrons in the Earth's radiation belts

Summary

Radiation belt formation for magnetically quiet and weakly disturbed conditions

Satellite data reveal many different types of plasma waves observed in near-Earth space. These waves play important roles in the transport of charged particles across L shells, as well as local acceleration and plasma heating, and energetic particle precipitation from the magnetosphere. Experimental data show that the most important waves, which regulate the population of the electron radiation belts (ERB), are whistler-mode electromagnetic waves in the ELF/VLF range. These waves arise in the magnetosphere from thunderstorm activity and via electron CM generation. The role of ELF/VLF waves in ERB formation has been investigated for a long time; see the review by Bespalov and Trakhtengerts (1986b) and books by Schulz and Lanzerotti (1974), Lyons and Williams (1984), Schulz (1991), and Hultqvist et al. (1999), and references therein. Their main contribution is pitch-angle scattering which can be decisive among the loss mechanisms for radiation belt (RB) electrons during magnetically disturbed periods. The most suitable approach for the description of pitch-angle scattering in the case of noise-like ELF/VLF emissions is quasi-linear theory, which has been developed in Chapters 8 and 9; see also Bespalov and Trakhtengerts (1986b) and Schulz (1991). For a comparison with the experimental data on RB particles and waves, the equations of QL theory should include all the real sources and sinks of RB electrons and ELF/VLF waves. The complete solution of this problem for a description of the real RB dynamics is rather complicated.