WALEN TEST AND DE HOFFMANN-TELLER FRAME OF INTERPLANETARY LARGE-AMPLITUDE ALFVEN WAVES

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	WALEN TEST AND DE HOFFMANN-TELLER FRAME OF INTERPLANETARY LARGE-AMPLITUDE ALFVEN WAVES
	Chao, J. K.1; Hsieh, Wen-Chieh 1; Yang, L.2 ; Lee, L. C.1,3
刊名	ASTROPHYSICAL JOURNAL
	2014-05-10
卷号	786 期号:2 页码:0
关键词	magnetohydrodynamics (MHD) plasmas solar wind waves
ISSN号	0004-637X
英文摘要	In this study, three methods of analysis are compared to test the Walen relation. Method 1 requires a good de Hoffmann-Teller ( HT) frame. Method 2 uses three components separately to find the frame that is slightly modified from Method 1. This method is intended to improve the accuracy of the HT frame and able to demonstrate the anisotropic property of the fluctuations. The better the relation is, the closer the slope of a regression fitting the data of plasma versus Alfven velocities is to 1. However, this criterion is based on an average HT frame, and the fitted slope does not always work for the Walen test because the HT frame can change so fast in the high-speed streams. We propose Method 3 to check the Walen relation using a sequence of data generated by taking the difference of two consecutive values of plasma and Alfven velocities, respectively. The difference data are independent of the HT frame. We suggest that the ratio of the variances between plasma and Alfven velocities is a better parameter to qualify the Walen relation. Four cases in two solar wind streams are studied using these three methods. Our results show that when the solar wind HT frame remains stable, all three methods can predict Alfvenic fluctuations well, but Method 3 can better predict the Walen relation when solar wind contains structures with several small streams. A simulated case also demonstrates that Method 3 is better and more robust than Methods 1 and 2. These results are important for a better understanding of Alfvenic fluctuations and turbulence in the solar wind.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	SOLAR-WIND ; ROTATIONAL DISCONTINUITIES ; TANGENTIAL DISCONTINUITIES ; EARTHS MAGNETOPAUSE ; MHD TURBULENCE ; BOUNDARY-LAYER ; PLASMA ; EVOLUTION ; FIELD ; RECONNECTION
收录类别	SCI
原文出处	10.1088/0004-637X/786/2/149
语种	英语
WOS记录号	WOS:000335884500072
公开日期	2014-11-20
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/10644]
专题	紫金山天文台_太阳和太阳系等离子体研究团组
作者单位	1.Natl Cent Univ, Inst Space Sci, Jhongli 320, Taiwan 2.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China 3.Acad Sinica, Inst Earth Sci, Taipei 115, Taiwan
推荐引用方式 GB/T 7714	Chao, J. K.,Hsieh, Wen-Chieh,Yang, L.,et al. WALEN TEST AND DE HOFFMANN-TELLER FRAME OF INTERPLANETARY LARGE-AMPLITUDE ALFVEN WAVES[J]. ASTROPHYSICAL JOURNAL,2014,786(2):0.
APA	Chao, J. K.,Hsieh, Wen-Chieh,Yang, L.,&Lee, L. C..(2014).WALEN TEST AND DE HOFFMANN-TELLER FRAME OF INTERPLANETARY LARGE-AMPLITUDE ALFVEN WAVES.ASTROPHYSICAL JOURNAL,786(2),0.
MLA	Chao, J. K.,et al."WALEN TEST AND DE HOFFMANN-TELLER FRAME OF INTERPLANETARY LARGE-AMPLITUDE ALFVEN WAVES".ASTROPHYSICAL JOURNAL 786.2(2014):0.