Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves

	Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves
	Zhu, Hui; Su, Zhenpeng; Xiao, Fuliang; Zheng, Huinan; Shen, Chao; Wang, Yuming; Wang, Shui
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
	2012
卷号	117 页码:A12217
ISSN号	0148-0227
通讯作者	Su, ZP (reprint author), Univ Sci & Technol China, Dept Geophys & Planetary Sci, CAS Key Lab Geospace Environm, Hefei 230026, Anhui, Peoples R China.
中文摘要	Electromagnetic ion cyclotron (EMIC) waves have long been suggested to account for the rapid decay of ring current, which is usually described by the quasi-linear theory. We demonstrate that the interactions between ring current protons and typical EMIC waves can be highly nonlinear. A dimensionless parameter R is derived to identify the nonlinear interaction region, and a test-particle simulation is performed to analyze the motions of typical (kinetic energy E-k = 50 keV) ring current protons in detail. Nonlinear phase bunching occurs widely in the region R similar to<1, whereas nonlinear phase trapping is confined in the region R similar to 1. The former produces the non-stochastic pitch angle decrease, probably increasing the overall loss rate predicted by the quasi-linear theory. In contrast, the latter causes the significant pitch angle increase, probably reducing the overall loss rate estimated from the quasi-linear theory. These two nonlinear mechanisms lead to complex advection and diffusion processes, and an advection-diffusion modeling is required to more accurately simulate the ring current decay induced by EMIC waves. Citation: Zhu, H., Z. Su, F. Xiao, H. Zheng, C. Shen, Y. Wang, and S. Wang (2012), Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves, J. Geophys. Res., 117, A12217, doi:10.1029/2012JA018088.
英文摘要	Electromagnetic ion cyclotron (EMIC) waves have long been suggested to account for the rapid decay of ring current, which is usually described by the quasi-linear theory. We demonstrate that the interactions between ring current protons and typical EMIC waves can be highly nonlinear. A dimensionless parameter R is derived to identify the nonlinear interaction region, and a test-particle simulation is performed to analyze the motions of typical (kinetic energy E-k = 50 keV) ring current protons in detail. Nonlinear phase bunching occurs widely in the region R similar to<1, whereas nonlinear phase trapping is confined in the region R similar to 1. The former produces the non-stochastic pitch angle decrease, probably increasing the overall loss rate predicted by the quasi-linear theory. In contrast, the latter causes the significant pitch angle increase, probably reducing the overall loss rate estimated from the quasi-linear theory. These two nonlinear mechanisms lead to complex advection and diffusion processes, and an advection-diffusion modeling is required to more accurately simulate the ring current decay induced by EMIC waves. Citation: Zhu, H., Z. Su, F. Xiao, H. Zheng, C. Shen, Y. Wang, and S. Wang (2012), Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves, J. Geophys. Res., 117, A12217, doi:10.1029/2012JA018088.
学科主题	空间物理
收录类别	SCI
资助信息	National Natural Science Foundation of China [41174125, 41131065, 41121003, 41074120]; Chinese Academy of Sciences [KZCX2-EW-QN510, KZZD-EW-01-4]; National Key Basic Research Special Foundation of China Grant [2011CB811403]; Fundamental Research Funds for the Central Universities [WK2080000031]
语种	英语
公开日期	2014-12-15
内容类型	期刊论文
源URL	[http://ir.nssc.ac.cn/handle/122/3071]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	Zhu, Hui,Su, Zhenpeng,Xiao, Fuliang,et al. Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2012,117:A12217.
APA	Zhu, Hui.,Su, Zhenpeng.,Xiao, Fuliang.,Zheng, Huinan.,Shen, Chao.,...&Wang, Shui.(2012).Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,117,A12217.
MLA	Zhu, Hui,et al."Nonlinear interaction between ring current protons and electromagnetic ion cyclotron waves".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 117(2012):A12217.