USING COORDINATED OBSERVATIONS IN POLARIZED WHITE LIGHT AND FARADAY ROTATION TO PROBE THE SPATIAL POSITION AND MAGNETIC FIELD OF AN INTERPLANETARY SHEATH
文献类型：期刊论文
| 作者 | Xiong, Ming1,2 ; Davies, Jackie A.; Feng, Xueshang1; Owens, Mathew J.3; Harrison, Richard A.; Davis, Chris J.3; Liu, Ying D.1
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| 刊名 | ASTROPHYSICAL JOURNAL
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| 出版日期 | 2013-11-01 |
| 卷号 | 777期号:1页码:32 |
| ISSN号 | 0004-642X |
| 关键词 | methods: numerical shock waves solar-terrestrial relations solar wind Sun: coronal mass ejections (CMEs) Sun: heliosphere |
| 通讯作者 | 北京8701信箱 |
| 中文摘要 | Coronal mass ejections (CMEs) can be continuously tracked through a large portion of the inner heliosphere by direct imaging in visible and radio wavebands. White light (WL) signatures of solar wind transients, such as CMEs, result from Thomson scattering of sunlight by free electrons and therefore depend on both viewing geometry and electron density. The Faraday rotation (FR) of radio waves from extragalactic pulsars and quasars, which arises due to the presence of such solar wind features, depends on the line-of-sight magnetic field component B∥ and the electron density. To understand coordinated WL and FR observations of CMEs, we perform forward magnetohydrodynamic modeling of an Earth-directed shock and synthesize the signatures that would be remotely sensed at a number of widely distributed vantage points in the inner heliosphere. Removal of the background solar wind contribution reveals the shock-associated enhancements in WL and FR. While the efficiency of Thomson scattering depends on scattering angle, WL radiance I decreases with heliocentric distance r roughly according to the expression I∝r −3. The sheath region downstream of the Earth-directed shock is well viewed from the L4 and L5 Lagrangian points, demonstrating the benefits of these points in terms of space weather forecasting. The spatial position of the main scattering site rsheath and the mass of plasma at that position Msheath can be inferred from the polarization of the shock-associated enhancement in WL radiance. From the FR measurements, the local B∥sheath at rsheath can then be estimated. Simultaneous observations in polarized WL and FR can not only be used to detect CMEs, but also to diagnose their plasma and magnetic field properties. |
| 英文摘要 | Coronal mass ejections (CMEs) can be continuously tracked through a large portion of the inner heliosphere by direct imaging in visible and radio wavebands. White light (WL) signatures of solar wind transients, such as CMEs, result from Thomson scattering of sunlight by free electrons and therefore depend on both viewing geometry and electron density. The Faraday rotation (FR) of radio waves from extragalactic pulsars and quasars, which arises due to the presence of such solar wind features, depends on the line-of-sight magnetic field component B-parallel to and the electron density. To understand coordinated WL and FR observations of CMEs, we perform forward magnetohydrodynamic modeling of an Earth-directed shock and synthesize the signatures that would be remotely sensed at a number of widely distributed vantage points in the inner heliosphere. Removal of the background solar wind contribution reveals the shock-associated enhancements in WL and FR. While the efficiency of Thomson scattering depends on scattering angle, WL radiance I decreases with heliocentric distance r roughly according to the expression I alpha r(-3). The sheath region downstream of the Earth-directed shock is well viewed from the L4 and L5 Lagrangian points, demonstrating the benefits of these points in terms of space weather forecasting. The spatial position of the main scattering site r(sheath) and the mass of plasma at that position M-sheath can be inferred from the polarization of the shock-associated enhancement in WL radiance. From the FR measurements, the local B-parallel to sheath at r(sheath) can then be estimated. Simultaneous observations in polarized WL and FR can not only be used to detect CMEs, but also to diagnose their plasma and magnetic field properties. |
| 学科主题 | 空间物理 |
| 语种 | 英语 |
| 源URL | [http://ir.cssar.ac.cn/handle/122/1495]  |
| 专题 | 国家空间科学中心_空间科学部 |
| 作者单位 | 1.Chinese Acad Sci, Ctr Space Sci & Appl Res, State Key Lab Space Weather, Beijing, Peoples R China 2.Beijing Aerosp Control Ctr, Sci & Technol Aerosp Flight Dynam Lab, Beijing, Peoples R China 3.Univ Reading, Reading, Berks, England |
| 推荐引用方式 GB/T 7714 | Xiong, Ming,Davies, Jackie A.,Feng, Xueshang,et al. USING COORDINATED OBSERVATIONS IN POLARIZED WHITE LIGHT AND FARADAY ROTATION TO PROBE THE SPATIAL POSITION AND MAGNETIC FIELD OF AN INTERPLANETARY SHEATH[J]. ASTROPHYSICAL JOURNAL,2013,777(1):32. |
| APA | Xiong, Ming.,Davies, Jackie A..,Feng, Xueshang.,Owens, Mathew J..,Harrison, Richard A..,...&Liu, Ying D..(2013).USING COORDINATED OBSERVATIONS IN POLARIZED WHITE LIGHT AND FARADAY ROTATION TO PROBE THE SPATIAL POSITION AND MAGNETIC FIELD OF AN INTERPLANETARY SHEATH.ASTROPHYSICAL JOURNAL,777(1),32. |
| MLA | Xiong, Ming,et al."USING COORDINATED OBSERVATIONS IN POLARIZED WHITE LIGHT AND FARADAY ROTATION TO PROBE THE SPATIAL POSITION AND MAGNETIC FIELD OF AN INTERPLANETARY SHEATH".ASTROPHYSICAL JOURNAL 777.1(2013):32. |
入库方式： OAI收割
来源：国家空间科学中心
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