气候变化领域集成服务门户(CCPortal): Frequency Dependence of Very Low Frequency Chorus Poynting Flux in the Source Region: THEMIS Observations and a Model

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DOI	10.1029/2020GL086958
	Frequency Dependence of Very Low Frequency Chorus Poynting Flux in the Source Region: THEMIS Observations and a Model
	Demekhov A.G.; Taubenschuss U.; Hanzelka M.; Santolík O.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:6
英文摘要	Using Poynting vector measurements of whistler mode chorus emissions detected by the THEMIS spacecraft within the source region, that is, close to the magnetic field minimum, we found both in individual events and statistically that chorus elements propagating equatorward had systematically higher frequencies and smaller amplitudes compared with simultaneously observed elements propagating away from the equator. We demonstrate similar features in the results of numerical simulations based on backward wave oscillator equations. It can be qualitatively explained by the nonlinear evolution of the energetic electron distribution function during wave generation. The motion of electrons from the equator is accompanied by a decrease in their velocity component along the magnetic field line due to both the adiabatic mirror force and nonlinear wave-particle interactions. Thus, the frequency of the chorus elements generated by such electrons and propagating equatorward is higher compared with the elements propagating away from the equator. ©2020. The Authors.
英文关键词	Distribution functions; Electromagnetic wave propagation; Electromagnetic waves; Magnetic fields; Magnetic mirrors; Microwave oscillators; Transport properties; Backward wave oscillator; Frequency dependence; Magnetic field line; Motion of electrons; Nonlinear evolutions; Velocity components; VLF chorus; Whistler-mode chorus; Atmospherics; detection method; measurement method; model; observational method; simulation; wave generation; wave propagation
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/170557
作者单位	Polar Geophysical Institute, Apatity, Russian Federation; Institute of Applied Physics of the Russian Academy of Sciences, Nizhny Novgorod, Russian Federation; Department of Space Physics, Institute of Atmospheric Physics, Czech Academy of Sciences, Prague, Czech Republic; Faculty of Mathematics and Physics, Charles University in Prague, Prague, Czech Republic
推荐引用方式 GB/T 7714	Demekhov A.G.,Taubenschuss U.,Hanzelka M.,et al. Frequency Dependence of Very Low Frequency Chorus Poynting Flux in the Source Region: THEMIS Observations and a Model[J],2020,47(6).
APA	Demekhov A.G.,Taubenschuss U.,Hanzelka M.,&Santolík O..(2020).Frequency Dependence of Very Low Frequency Chorus Poynting Flux in the Source Region: THEMIS Observations and a Model.Geophysical Research Letters,47(6).
MLA	Demekhov A.G.,et al."Frequency Dependence of Very Low Frequency Chorus Poynting Flux in the Source Region: THEMIS Observations and a Model".Geophysical Research Letters 47.6(2020).