The upstream-propagating Alfvenic fluctuations with power law spectra in   the upstream region of the Earth&apos;s bow shock

doi:10.1002/2015GL063893

CORC > 北京大学 > 地球与空间科学学院

	The upstream-propagating Alfvenic fluctuations with power law spectra in the upstream region of the Earth's bow shock
	Wang, Xin ; Tu, Chuanyi ; Wang, Linghua ; He, Jiansen ; Marsch, Eckart
刊名	GEOPHYSICAL RESEARCH LETTERS
	2015
关键词	solar wind turbulence Alfven waves energetic particles HYDROMAGNETIC WAVE EXCITATION ION-ACCELERATION UPSTREAM SOLAR-WIND TURBULENCE MAGNETIC-FIELD FORESHOCK PLASMA EXISTENCE PROTONS EVENTS
DOI	10.1002/2015GL063893
英文摘要	Based on theories, the beam instability induced by shock-accelerated ions can generate upstream-propagating Alfven waves (UPAWs) with a power spectral bump near 0.03Hz, while the nonlinear wave-wave interaction favors an inverse cascade to create a power law spectrum. Here we present the first observational evidence for the upstream-propagating Alfvenic fluctuations (UPAFs) with power law spectra. We utilize a new criterion to identify the upstream-propagating Alfvenic intervals: the propagation direction is opposite to that of solar wind strahl electron outflow. Besides 35 UPAWs, we find 47 UPAFs with power law spectra, and approximate to 47% of these UPAFs are associated with energetic ion events (>30keV). These UPAWs and UPAFs are mostly observed in the slow solar wind. However, their occurrence rate and power behave differently in dependence on the radial distance from the Earth. These results provide new clues on understanding the dynamic equilibrium between the nonlinear inverse cascade and the linear ion beam instability.; NSFC [41421003, 41474147, 40931055, 41231069, 41274172, 41474148, 41222032]; SCI(E); EI; ARTICLE; wanglhwang@gmail.com; 10; 3654-3661; 42
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/419917]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Wang, Xin,Tu, Chuanyi,Wang, Linghua,et al. The upstream-propagating Alfvenic fluctuations with power law spectra in the upstream region of the Earth's bow shock[J]. GEOPHYSICAL RESEARCH LETTERS,2015.
APA	Wang, Xin,Tu, Chuanyi,Wang, Linghua,He, Jiansen,&Marsch, Eckart.(2015).The upstream-propagating Alfvenic fluctuations with power law spectra in the upstream region of the Earth's bow shock.GEOPHYSICAL RESEARCH LETTERS.
MLA	Wang, Xin,et al."The upstream-propagating Alfvenic fluctuations with power law spectra in the upstream region of the Earth's bow shock".GEOPHYSICAL RESEARCH LETTERS (2015).