On the Hardness of the Photoelectron Energy Spectrum Near Mars
文献类型：期刊论文
| 作者 | Wu, X. -S.1,3,4; Cui, J.1,3,4; Cao, Y. -T.1; Liu, L. - J.3,4; Zhou, Z. -J.3,4; Huang, Y. -Y.3; He, F.2; Wei, Y.2 |
| 刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
 |
| 出版日期 | 2019-11-06 |
| 页码 | 9 |
| ISSN号 | 2169-9097 |
| 关键词 | Mars photoelectron |
| DOI | 10.1029/2019JE006093 |
| 英文摘要 | Photoelectrons are an important population of the dayside Martian upper atmosphere that contributes substantially to the local ionization and heat balances. This study is focused on the broad shape of the photoelectron energy spectrum at 10-50 eV. Assuming a power law distribution, we derive the hardness of each photoelectron energy spectrum measured on the dayside of Mars by the Solar Wind Electron Analyzer on board the Mars Atmosphere and Volatile Evolution spacecraft. Our analysis reveals two distinctive features: (1) The hardness tends to increase with decreasing altitude down to 140 km and then decrease toward lower altitudes; (2) the hardness tends to decrease with increasing solar zenith angle. These variations are restricted to regions below 250 km whereas the hardness appears to be fairly constant at higher altitudes. In practice, the hardness is modulated by the ionization of atmospheric neutrals by solar Extreme Ultraviolet and X-ray photons, inelastic collisions with atmospheric neutrals, Coulomb collisions with ionospheric thermal electrons, and photoelectron transport. While inelastic collisions tend to harden the photoelectron energy spectrum, both primary production and Coulomb collisions tend to soften it instead. We argue that the observed variations of the hardness can be understood in terms of the relative contributions of different processes. Our analysis also suggests the presence of appreciable temporal variability in hardness with a typical timescale of 10 min. |
| WOS关键词 | AE-E MEASUREMENTS ; ATMOSPHERE EXPLORER ; ELECTRON ; PREDICTIONS ; IONOSPHERE ; DEPOSITION ; FLUXES ; MODEL ; PEAKS |
| 资助项目 | Strategic Priority Research Program of the Chinese Academy of Sciences[XDA17010201] ; National Science Foundation of China[41525015] ; National Science Foundation of China[41774186] ; National Science Foundation of China[41525016] |
| WOS研究方向 | Geochemistry & Geophysics |
| 语种 | 英语 |
| 出版者 | AMER GEOPHYSICAL UNION |
| WOS记录号 | WOS:000494629800001 |
| 资助机构 | Strategic Priority Research Program of the Chinese Academy of Sciences ; Strategic Priority Research Program of the Chinese Academy of Sciences ; National Science Foundation of China ; National Science Foundation of China ; Strategic Priority Research Program of the Chinese Academy of Sciences ; Strategic Priority Research Program of the Chinese Academy of Sciences ; National Science Foundation of China ; National Science Foundation of China ; Strategic Priority Research Program of the Chinese Academy of Sciences ; Strategic Priority Research Program of the Chinese Academy of Sciences ; National Science Foundation of China ; National Science Foundation of China ; Strategic Priority Research Program of the Chinese Academy of Sciences ; Strategic Priority Research Program of the Chinese Academy of Sciences ; National Science Foundation of China ; National Science Foundation of China |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/95708]  |
| 专题 | 地质与地球物理研究所_中国科学院地球与行星物理重点实验室 |
| 通讯作者 | Cui, J. |
| 作者单位 | 1.Chinese Acad Sci, Natl Astron Observ, Beijing, Peoples R China 2.Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China 3.Chinese Acad Sci, Ctr Excellence Comparat Planetol, Hefei, Anhui, Peoples R China 4.Sun Yat Sen Univ, Sch Atmospher Sci, Zhuhai, Peoples R China |
| 推荐引用方式 GB/T 7714 | Wu, X. -S.,Cui, J.,Cao, Y. -T.,et al. On the Hardness of the Photoelectron Energy Spectrum Near Mars[J]. JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS,2019:9. |
| APA | Wu, X. -S..,Cui, J..,Cao, Y. -T..,Liu, L. - J..,Zhou, Z. -J..,...&Wei, Y..(2019).On the Hardness of the Photoelectron Energy Spectrum Near Mars.JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS,9. |
| MLA | Wu, X. -S.,et al."On the Hardness of the Photoelectron Energy Spectrum Near Mars".JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS (2019):9. |
入库方式： OAI收割
来源：地质与地球物理研究所
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