DOI: 10.1002/2017JA024813
Scopus记录号: 2-s2.0-85040789306
论文题名: Ion-Scale Spectral Break in the Normal Plasma Beta Range in the Solar Wind Turbulence
作者: Wang X. ; Tu C.-Y. ; He J.-S. ; Wang L.-H.
刊名: Journal of Geophysical Research: Space Physics
ISSN: 21699380
出版年: 2018
卷: 123, 期: 1 起始页码: 68
结束页码: 75
语种: 英语
英文关键词: dissipation
; magnetic field
; solar wind turbulence
; spectral break
英文摘要: The spectral break (fb) of magnetic fluctuations at the ion scale in the solar wind is considered to give important clue on the turbulence dissipation mechanism. Among several possible mechanisms, the most notable two are related respectively to proton thermal gyroradius ρi and proton inertial length di. The corresponding frequencies of them are fρi=VSW/(2πρi) and fdi=VSW/(2πdi), respectively, where VSW is the solar wind speed. However, no definite conclusion has been given for which one is more reasonable because the two parameters have similar value when plasma beta β ∼ 1. Here we do a statistical study to see if the two ratios fb/fρi and fb/fdi have different dependence on β in the solar wind turbulence with 0.1 < β < 1.3. From magnetic measurements by the Wind spacecraft, we select 141 data sets with each one longer than 13 h. We find that the ratio fb/fdi is statistically not dependent on β, and the average value of it is 0.48 ± 0.06. However, fb/fρi increases with increasing β clearly and is significantly smaller than fb/fdi when β < 0.8. These new results show that fb is statistically 0.48fdi, and the influence of β could be negligible in the studied β range. It indicates a preference of the dissipation mechanism associated with di in the solar wind with 0.1 < β < 0.8. Further theoretical studies are needed to give detailed explanation. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/114762
Appears in Collections: 气候减缓与适应
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作者单位: School of Space and Environment, Beihang University, Beijing, China; School of Earth and Space Sciences, Peking University, Beijing, China
Recommended Citation:
Wang X.,Tu C.-Y.,He J.-S.,et al. Ion-Scale Spectral Break in the Normal Plasma Beta Range in the Solar Wind Turbulence[J]. Journal of Geophysical Research: Space Physics,2018-01-01,123(1)