Composition of Wave Modes in Magnetosheath Turbulence from Sub-ion to Sub-electron Scales
文献类型：期刊论文
| 作者 | Zhu, Xingyu1; He, Jiansen1; Verscharen, Daniel2,3; Zhao, Jinsong4
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| 刊名 | ASTROPHYSICAL JOURNAL
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| 出版日期 | 2019-06-10 |
| 卷号 | 878期号:1页码:10 |
| 关键词 | turbulence waves |
| ISSN号 | 0004-637X |
| DOI | 10.3847/1538-4357/ab1be7 |
| 通讯作者 | Zhao, Jinsong(jshept@pku.edu.cn) |
| 英文摘要 | The nature of plasma turbulence remains unclear at kinetic scales, especially sub-electron scales. We simultaneously investigate spectra of magnetic and electric fields from proton scales (similar to 1 Hz) down to sub-electron scales (similar to 1 kHz) using MMS measurements in the magnetosheath turbulence. We find that magnetic field spectra exhibit identical behavior between ion and electron scales, while they bifurcate at about 30 Hz (around electron inertial scale) and then aggregate around 1 kHz (around electron gyrofrequency). Kinetic Alfven waves (KAWs) are identified in the range from 1 to 30 Hz: (1) the power spectral indices of PSD(B) and PSD(E) are about -3 and -1; (2) parallel magnetic and electric fluctuations are present but subdominant. Magnetic field spectra obtained from postnoon region events show a clear spectral enhancement, which is identified as quasi-parallel whistler waves (WWs). Electric field spectra present a wide bulge around 800 Hz, which is also seen as island-like patterns in the time-period wavelet spectra. The electric field spectral enhancement is dominated by field-parallel fluctuations and is, therefore, diagnosed as ion acoustic waves (IAWs). We also perform a quantitative analysis of the multiple mode types using polarization predictions from two-fluid theory. We obtain the energy partition of electromagnetic fields for different wave modes and successfully reproduce the observed PSDs of B-perpendicular to, B-parallel to, E-perpendicular to, and E-parallel to. Our findings suggest that the magnetosheath turbulence consists of a mixture of multiple wave modes (KAW, WW, and IAW) in the range from sub-ion scales to sub-electron scales. |
| WOS关键词 | SOLAR-WIND ; SEPARATRIX REGIONS ; DISPERSION ; SPECTRA ; MHD |
| WOS研究方向 | Astronomy & Astrophysics |
| 语种 | 英语 |
| WOS记录号 | WOS:000471316800011 |
| 出版者 | IOP PUBLISHING LTD |
| 源URL | [http://libir.pmo.ac.cn/handle/332002/27495]  |
| 专题 | 中国科学院紫金山天文台 |
| 通讯作者 | Zhao, Jinsong |
| 作者单位 | 1.Peking Univ, Sch Earth & Space Sci, Beijing 100871, Peoples R China 2.Univ Coll London, Mullard Space Sci Lab, Dorking RH5 6NT, Surrey, England 3.Univ New Hampshire, Space Sci Ctr, Durham, NH 03824 USA 4.Chinese Acad Sci, Purple Mt Observ, Nanjing 210008, Jiangsu, Peoples R China |
| 推荐引用方式 GB/T 7714 | Zhu, Xingyu,He, Jiansen,Verscharen, Daniel,et al. Composition of Wave Modes in Magnetosheath Turbulence from Sub-ion to Sub-electron Scales[J]. ASTROPHYSICAL JOURNAL,2019,878(1):10. |
| APA | Zhu, Xingyu,He, Jiansen,Verscharen, Daniel,&Zhao, Jinsong.(2019).Composition of Wave Modes in Magnetosheath Turbulence from Sub-ion to Sub-electron Scales.ASTROPHYSICAL JOURNAL,878(1),10. |
| MLA | Zhu, Xingyu,et al."Composition of Wave Modes in Magnetosheath Turbulence from Sub-ion to Sub-electron Scales".ASTROPHYSICAL JOURNAL 878.1(2019):10. |
入库方式： OAI收割
来源：紫金山天文台
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