Energy transfer from lower energy to higher‐energy electrons mediated by whistler waves in the radiation belts. Issue 1 (26th January 2017)

• Record Type: Journal Article
• Authors: Shklyar, D. R.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 1(2017)
• Page Start: 640
• Page End: 655
• Publication Date: 2017-01-26
• Subjects: energy transfer -- unstable plasma -- whistler mode waves -- resonant wave‐particle interactions -- radiation belts; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2016JA023263
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: We study the problem of energy exchange between waves and particles, which leads to energization of the latter, in an unstable plasma typical of the radiation belts. The ongoing Van Allen Probes space mission brought this problem among the most discussed in space physics. A free energy which is present in an unstable plasma provides the indispensable condition for energy transfer from lower energy particles to higher‐energy particles via resonant wave‐particle interaction. This process is studied in detail by the example of electron interactions with whistler mode wave packets originated from lightning‐induced emission. We emphasize that in an unstable plasma, the energy source for electron energization is the energy of other particles, rather than the wave energy as is often assumed. The way by which the energy is transferred from lower energy to higher‐energy particles includes two processes that operate concurrently, in the same space‐time domain, or sequentially, in different space‐time domains, in which a given wave packet is located. In the first process, one group of resonant particles gives the energy to the wave. The second process consists in wave absorption by another group of resonant particles, whose energy therefore increases. We argue that this mechanism represents an efficient means of electron energization in the radiation belts. Key Points: Energy transfer between two groups of particles is an intrinsic feature of resonant wave‐particle interaction In an unstable plasma, wave‐mediated energy transfer from lower energy to higher‐energy particles is possible and takes place Lightning‐induced and other source whistler waves are the means of electron energization in the radiation belts