Spatial distribution of Kelvin-Helmholtz instability at low-latitude boundary layer under different solar wind speed conditions
文献类型：期刊论文
| 作者 | Li, W. Y.; Guo, X. C.; Wang, C. |
| 刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
 |
| 出版日期 | 2012 |
| 卷号 | 117页码:A08230 |
| ISSN号 | 0148-0227 |
| 通讯作者 | Li, WY (reprint author), Chinese Acad Sci, State Key Lab Space Weather, Ctr Space Sci & Appl Res, Beijing 100190, Peoples R China. |
| 中文摘要 | Using the PPMLR-MHD global simulation model, we examined the Kelvin-Helmholtz (K-H) instability at the low-latitude boundary layer (LLBL) under northward interplanetary magnetic field (IMF) conditions with various solar wind speeds (400, 600, and 800 km/s). The spatial distribution of the K-H wave power in the equatorial plane shows two distinct power populations, referring to the two modes of K-H surface waves. The spatial evolution of K-H instability at the boundary layer is classified into four phases: quasi-stable, exponential growth, linear growth, and nonlinear phases. The boundary layer is quasi-stable near the subsolar point region. The K-H instability starts at about 30 degrees longitude, and grows exponentially with a spatial growth rate of 0.28 similar to 0.87 R-E(-1) until similar to 45 degrees longitude where the vortices fully develop. At larger longitudes, the instability grows linearly, while the vortices grow in size. From similar to 80 degrees longitude to the distant magnetotail, the K-H instability develops nonlinearly and the vortices roll up. The wave frequency, wavelength, and phase speed are given at various spatial points. Model results show that the higher solar wind speed generates K-H waves with higher frequency under the northward IMF, and the wavelengths and the phase speeds increase with the increase of the longitude. Moreover, we made a comparison of the K-H wave periods on Earth's, Mercury's and Saturn's magnetopauses by a proposed prediction method. |
| 英文摘要 | Using the PPMLR-MHD global simulation model, we examined the Kelvin-Helmholtz (K-H) instability at the low-latitude boundary layer (LLBL) under northward interplanetary magnetic field (IMF) conditions with various solar wind speeds (400, 600, and 800 km/s). The spatial distribution of the K-H wave power in the equatorial plane shows two distinct power populations, referring to the two modes of K-H surface waves. The spatial evolution of K-H instability at the boundary layer is classified into four phases: quasi-stable, exponential growth, linear growth, and nonlinear phases. The boundary layer is quasi-stable near the subsolar point region. The K-H instability starts at about 30 degrees longitude, and grows exponentially with a spatial growth rate of 0.28 similar to 0.87 R-E(-1) until similar to 45 degrees longitude where the vortices fully develop. At larger longitudes, the instability grows linearly, while the vortices grow in size. From similar to 80 degrees longitude to the distant magnetotail, the K-H instability develops nonlinearly and the vortices roll up. The wave frequency, wavelength, and phase speed are given at various spatial points. Model results show that the higher solar wind speed generates K-H waves with higher frequency under the northward IMF, and the wavelengths and the phase speeds increase with the increase of the longitude. Moreover, we made a comparison of the K-H wave periods on Earth's, Mercury's and Saturn's magnetopauses by a proposed prediction method. |
| 学科主题 | 空间物理 |
| 资助信息 | 973 program [2012CB825602]; NNSFC [40921063, 40831060]; Specialized Research Fund for State Key Laboratories of China |
| 收录类别 | SCI |
| 语种 | 英语 |
| 公开日期 | 2014-12-15 |
| 源URL | [http://ir.nssc.ac.cn/handle/122/3220]  |
| 专题 | 国家空间科学中心_空间科学部 |
| 推荐引用方式 GB/T 7714 | Li, W. Y.,Guo, X. C.,Wang, C.. Spatial distribution of Kelvin-Helmholtz instability at low-latitude boundary layer under different solar wind speed conditions[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2012,117:A08230. |
| APA | Li, W. Y.,Guo, X. C.,&Wang, C..(2012).Spatial distribution of Kelvin-Helmholtz instability at low-latitude boundary layer under different solar wind speed conditions.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,117,A08230. |
| MLA | Li, W. Y.,et al."Spatial distribution of Kelvin-Helmholtz instability at low-latitude boundary layer under different solar wind speed conditions".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 117(2012):A08230. |
入库方式： OAI收割
来源：国家空间科学中心
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