| Observations of kinetic Alfvén waves by THEMIS near a substorm onset |
| |
| 作者姓名： | ANGELOPOULOS Vassilis |
| |
| 作者单位： | Institute of Geophysics and Planetary Physics,University of California,Los Angeles,California 90095,USA |
| |
| 基金项目： | We acknowledge the NASA contract NAS5-02099 for making available data from the THEM1S mission. We thank the NASA CDA Web and Taiwan AIDA for THEMIS data and the Kyoto Worm Data Center for providing the AE, AL and AU indices. This work was supported by the National Nat- ural Science Foundation of China （40974099, 40731054, 40704027 and 40921063）, the Specialized Research Fund for State Key Laboratories and the National Basic Research Program of China （2011 CB811404）. |
| |
| 摘 要： | Low frequency electromagnetic fluctuations in the vicinity of a magnetospheric substorm onset were investigated using simultaneous observations by THEMIS multiple probes in the near-Earth plasma sheet in the magnetotail.The observations indicate that in the vicinity of a substorm onset,kinetic Alfvén waves can be excited in the high-βplasma sheet(β=2μ0nT/B 2 ,the ratio of plasma thermal pressure to magnetic pressure)within the near-Earth magnetotail.The kinetic Alfvén wave has a small spatial scale in the high-βplasma.The parallel electric field accompanying kinetic Alfvén waves accelerates the charged particles along the magnetic field.The kinetic Alfvén waves play an important role in the substorm trigger process,and possibly in the formation of a substorm current wedge.
|
| 关 键 词： | kinetic Alfvén wave near-Earth plasma sheet substorm onset |
| 本文献已被 CNKI 维普 SpringerLink 等数据库收录！ |
|
