Generation process of large-amplitude upper band chorus emissions observed by Van Allen Probes

TitleGeneration process of large-amplitude upper band chorus emissions observed by Van Allen Probes
Publication TypeJournal Article
Year of Publication2018
AuthorsKubota, Y, Omura, Y, Kletzing, C, Reeves, G
JournalJournal of Geophysical Research: Space Physics
Date Published04/2018
KeywordsChorus; energetic electrons; nonlinear wave‐particle interaction; observation; Radiation belt; Van Allen Probes
AbstractWe analyze large‐amplitude upper‐band chorus emissions measured near the magnetic equator by the EMFISIS (Electric and Magnetic Field Instrument Suite and Integrated Science) instrument package onboard the Van Allen Probes. In setting up the parameters of source electrons exciting the emissions based on theoretical analyses and observational results measured by the HOPE (Helium Oxygen Proton Electron) instrument, we calculate threshold and optimum amplitudes with the nonlinear wave growth theory. We find that the optimum amplitude is larger than the threshold amplitude obtained in the frequency range of the chorus emissions and that the wave amplitudes grow between the threshold and optimum amplitudes. In the frame of the wave growth process, the nonlinear growth rates are much greater than the linear growth rates.
URLhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2017JA024782
DOI10.1029/2017JA024782
Short TitleJ. Geophys. Res. Space Physics


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