Equatorial electromagnetic emission with discrete spectra near harmonics of oxygen gyrofrequency during magnetic storm
Equatorial electromagnetic emission with discrete spectra near harmonics of oxygen gyrofrequency during magnetic storm
复制标题
DOI：
10.1029/93gl02836
复制
发表时间：
1994-02
影响因子：
5.2
通讯作者：
Haijiang Liu;S. Kokubun;K. Hayashi
中科院分区：
文献类型：
--
作者：
Haijiang Liu;S. Kokubun;K. Hayashi
在磁暴期间，利用Akebono卫星上的三轴搜索线圈和单分量电场仪器，在低高度等离子体层（L = 1.5 <$2.5）中观测到了环电流高度活跃的赤道电磁极低频发射，其频率范围在氧离子回旋频率附近。我们发现在磁暴主相期间，在氧离子（O+）的本地回旋频率（Fo+）附近出现了一种特殊类型的ELF辐射，它具有多波段的光谱结构。我们的发现包括以下几个方面：多波段的发射是本地化的早晨部门，往往由几个间隔的频带密切相关的本地陀螺谐波的氧离子（O+）的基频Fo+或2Fo+。每个波段的频率取决于沿着卫星轨道的局部磁场变化，波段之间的间隔几乎等于Fo+或2Fo+。认为磁暴主相期间，构成环电流区的地球氧离子产生了辐射。
Equatorial electromagnetic ELF emissions at a frequency range around the oxygen ion gyrofrequency were observed in the low altitude plasmasphere (L = 1.5∼2.5) during magnetic storms with high activity of the ring current by triaxial search coil and single component electric field instruments on board the Akebono satellite. We find that a particular type of the ELF emissions occur with a multi-band spectral structure around the local gyrofrequency (Fo+) of the oxygen ion (O+) during the main phase of magnetic storm. Our finding includes the following; The multi-band emissions are localized in the morning sector and often consist of several spaced frequency bands closely related the local gyro-harmonics of oxygen ion (O+) with a fundamental frequency of Fo+ or 2Fo+. The frequency of each band is dependent on the local magnetic field variation along the satellite orbit and the spacing between the bands is almost equal to Fo+ or 2Fo+. It is suggested that emissions are generated by terrestrial oxygen ion composing the ring current area during the main phase of magnetic storm.