Nonlinear coupling between whistler-mode chorus and electron cyclotron harmonic waves in the magnetosphere

TitleNonlinear coupling between whistler-mode chorus and electron cyclotron harmonic waves in the magnetosphere
Publication TypeJournal Article
Year of Publication2018
AuthorsGao, Z, Su, Z, Xiao, F, Summers, D, Liu, N, Zheng, H, Wang, Y, Wei, F, Wang, S
JournalGeophysical Research Letters
Date Published11/2018
Keywordsaurora; Chorus wave; electron cyclotron harmonic wave; nonlinear wave‐wave interaction; Radiation belt; Van Allen Probes
AbstractElectromagnetic whistler‐mode chorus and electrostatic electron cyclotron harmonic (ECH) waves can contribute significantly to auroral electron precipitation and radiation belt electron acceleration. In the past, linear and nonlinear wave‐particle interactions have been proposed to explain the occurrences of these magnetospheric waves. By analyzing Van Allen Probes data, we present here the first evidence for nonlinear coupling between chorus and ECH waves. The sum‐frequency and difference‐frequency interactions produced the ECH sidebands with discrete frequency sweeping structures exactly corresponding to the chorus rising tones. The newly‐generated weak sidebands did not satisfy the original electrostatic wave dispersion relation. After the generation of chorus and normal ECH waves by hot electron instabilities, the nonlinear wave‐wave interactions could additionally redistribute energy among the resonant waves, potentially affecting to some extent the magnetospheric electron dynamics.
URLhttps://agupubs.onlinelibrary.wiley.com/doi/10.1029/2018GL080635
DOI10.1029/2018GL080635
Short TitleGeophys. Res. Lett.


Page Last Modified: December 6, 2018