Generation of nonlinear Electric Field Bursts in the outer radiation belt through the parametric decay of whistler waves

TitleGeneration of nonlinear Electric Field Bursts in the outer radiation belt through the parametric decay of whistler waves
Publication TypeJournal Article
Year of Publication2015
AuthorsAgapitov, OV, Krasnoselskikh, V, Mozer, FS, Artemyev, AV, Volokitin, AS
JournalGeophysical Research Letters
Date Published05/2015
Keywordselectron acoustic waves; nonlinear structure formation; parametric decay of whistlers; Van Allen Probes
AbstractHuge numbers of different non-linear structures (double layers, electron holes, non-linear whistlers, etc. referred to as Time Domain Structures - TDS) have been observed by the electric field experiment on the Van Allen Probes. Some of them are associated with whistler waves. Such TDS often emerge on the forward edges of the whistler wave packets and form chains. The parametric decay of a whistler wave into a whistler wave propagating in the opposite direction and an electron acoustic wave is studied experimentally as well as analytically, using Van Allen Probes data. The resulting electron acoustic wave is considered to be the source of electron scale TDS. The measured parameters of the three waves (two whistlers and the electron acoustic wave) are in a good agreement with an assumption of their parametric interaction: ω0 = ω1 + ω2 and inline image. The bi-coherence analysis shows the non-linear nature of the observed electron-acoustic waves as well as the whistler wave and electron acoustic wave phase relation. The estimated decay instability growth rate shows that the process of three wave interaction can develop in a characteristic time smaller than one second, thus the process is rapid enough to explain the observations. This induced parametric interaction can be one of the mechanisms for quasi-periodic TDS generation in the outer Van Allen radiation belt.
URLhttp://doi.wiley.com/10.1002/2015GL064145
DOI10.1002/2015GL064145
Short TitleGeophys. Res. Lett.


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