Effect of subauroral polarization streams on the thermosphere: A statistical study
文献类型：期刊论文
| 作者 | Wang, Hui; Luehr, Hermann; Haeusler, Kathrin; Ritter, Patricia |
| 刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
 |
| 出版日期 | 2011 |
| 卷号 | 116页码:A03312 |
| ISSN号 | 0148-0227 |
| 通讯作者 | Wang, H (reprint author), Wuhan Univ, Dept Space Phys, Sch Elect Informat, Wuhan 430079, Hubei, Peoples R China. |
| 中文摘要 | Using 2 years of coordinated CHAMP and DMSP observations we have investigated for the first time the relationship between subauroral polarization streams (SAPS), ionospheric Hall current (electrojet), upper thermospheric zonal wind, and mass density at subauroral regions in the dusk and premidnight sectors, separately for both hemispheres. For comparison, we have also analyzed the same parameters as a function of magnetic latitude (30 degrees-80 degrees magnetic latitude) during non-SAPS periods. During periods of non-SAPS, the neutral wind exhibits similar features as during SAPS events in the dusk to premidnight sector, streaming westward in the same direction as the plasma drift. Both neutral and plasma velocities peak at the same latitude regardless of SAPS occurrence. For higher geomagnetic activity both velocities are faster and the peaks shift equatorward. During non-SAPS periods, the ratio between plasma and neutral wind velocity is on average 2.75 +/- 0.4 in both hemispheres irrespective of geomagnetic activity. The neutral wind during SAPS events gets enhanced by a factor of 1.5/1.2 for Kp < 4 and 1.3/1.9 for Kp >= 4 in the Northern/Southern Hemisphere, respectively, as compared to non-SAPS time. The velocity difference between SAPS and neutral wind is also larger during SAPS period than during non-SAPS period, and the difference tends to increase with increasing geomagnetic activity. The peak latitude of the eastward auroral electrojet appears 1.5 degrees poleward of the plasma drift during SAPS events, confirming the formation of SAPS equatorward of the high-conductivity channel. These SAPS-induced large winds can heat the upper thermosphere. As a result we observe a 10% enhanced mass density at 400 km altitude with respect to periods without SAPS. In addition a density anomaly peak occurs collocated with the SAPS, displaced from the electrojet peak. We regard this as an indication for efficient thermospheric heating by ion neutral friction. |
| 英文摘要 | Using 2 years of coordinated CHAMP and DMSP observations we have investigated for the first time the relationship between subauroral polarization streams (SAPS), ionospheric Hall current (electrojet), upper thermospheric zonal wind, and mass density at subauroral regions in the dusk and premidnight sectors, separately for both hemispheres. For comparison, we have also analyzed the same parameters as a function of magnetic latitude (30 degrees-80 degrees magnetic latitude) during non-SAPS periods. During periods of non-SAPS, the neutral wind exhibits similar features as during SAPS events in the dusk to premidnight sector, streaming westward in the same direction as the plasma drift. Both neutral and plasma velocities peak at the same latitude regardless of SAPS occurrence. For higher geomagnetic activity both velocities are faster and the peaks shift equatorward. During non-SAPS periods, the ratio between plasma and neutral wind velocity is on average 2.75 +/- 0.4 in both hemispheres irrespective of geomagnetic activity. The neutral wind during SAPS events gets enhanced by a factor of 1.5/1.2 for Kp < 4 and 1.3/1.9 for Kp >= 4 in the Northern/Southern Hemisphere, respectively, as compared to non-SAPS time. The velocity difference between SAPS and neutral wind is also larger during SAPS period than during non-SAPS period, and the difference tends to increase with increasing geomagnetic activity. The peak latitude of the eastward auroral electrojet appears 1.5 degrees poleward of the plasma drift during SAPS events, confirming the formation of SAPS equatorward of the high-conductivity channel. These SAPS-induced large winds can heat the upper thermosphere. As a result we observe a 10% enhanced mass density at 400 km altitude with respect to periods without SAPS. In addition a density anomaly peak occurs collocated with the SAPS, displaced from the electrojet peak. We regard this as an indication for efficient thermospheric heating by ion neutral friction. |
| 学科主题 | 空间物理 |
| 收录类别 | SCI |
| 资助信息 | Federal Ministry of Education (BMBF); National Nature Science Foundation of China [40604017, 40974096]; National Basic Research Program of China (973 Program) [2011CB811404]; Geotechnology Programme; State Key Laboratory of Space Weather of Chinese Academy of Sciences; Scientific Research Foundation for the Returned Overseas Chinese Scholars; State Education Ministry; Fundamental Research Funds for the Central Universities |
| 语种 | 英语 |
| 公开日期 | 2014-12-15 |
| 源URL | [http://ir.nssc.ac.cn/handle/122/3140]  |
| 专题 | 国家空间科学中心_空间科学部 |
| 推荐引用方式 GB/T 7714 | Wang, Hui,Luehr, Hermann,Haeusler, Kathrin,et al. Effect of subauroral polarization streams on the thermosphere: A statistical study[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2011,116:A03312. |
| APA | Wang, Hui,Luehr, Hermann,Haeusler, Kathrin,&Ritter, Patricia.(2011).Effect of subauroral polarization streams on the thermosphere: A statistical study.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,116,A03312. |
| MLA | Wang, Hui,et al."Effect of subauroral polarization streams on the thermosphere: A statistical study".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 116(2011):A03312. |
入库方式： OAI收割
来源：国家空间科学中心
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