Chorus source region localization in the Earth's outer magnetosphere using THEMIS measurements
Chorus source region localization in the Earth's outer magnetosphere using THEMIS measurements
复制标题
使用 THEMIS 测量在地球外磁层中合唱源区域定位
DOI：
10.5194/angeo-28-1377-2010
复制
发表时间：
2010
影响因子：
1.9
通讯作者：
G. Rolland
中科院分区：
文献类型：
--
作者：
O. Agapitov;V. Krasnoselskikh;Y. Zaliznyak;V. Angelopoulos;O. Contel;G. Rolland
抽象的。离散的极低频/甚低频合唱发射是在地球辐射带和外磁层中观察到的最强烈的电磁等离子体波，被认为大致沿着磁力线从磁赤道附近的局部源区向磁极传播。利用THEMIS项目电场仪器(EFI)和搜索线圈磁强计(SCM)的测量，确定了地球外层磁层白天一侧合唱源定位区域的空间尺度。我们介绍了2007年在几个THEMIS航天器上登记的相同合唱元素的同时观测，当时所有航天器都在同一轨道上。在局地电子回转频率的0.15-0.25处观察到离散的合唱元素，这在外磁层是典型的。我们计算了Pointing磁通和波矢分布，得到了和声波包准平行于局部磁场的传播。幅度和相位相关数据的分析使我们能够估计出横向于局部磁场的特征空间相关尺度在2800-3200公里范围内。
Abstract. Discrete ELF/VLF chorus emissions, the most intense electromagnetic plasma waves observed in the Earth's radiation belts and outer magnetosphere, are thought to propagate roughly along magnetic field lines from a localized source region near the magnetic equator towards the magnetic poles. THEMIS project Electric Field Instrument (EFI) and Search Coil Magnetometer (SCM) measurements were used to determine the spatial scale of the chorus source localization region on the day side of the Earth's outer magnetosphere. We present simultaneous observations of the same chorus elements registered onboard several THEMIS spacecraft in 2007 when all the spacecraft were in the same orbit. Discrete chorus elements were observed at 0.15–0.25 of the local electron gyrofrequency, which is typical for the outer magnetosphere. We evaluated the Poynting flux and wave vector distribution and obtained chorus wave packet quasi-parallel propagation to the local magnetic field. Amplitude and phase correlation data analysis allowed us to estimate the characteristic spatial correlation scale transverse to the local magnetic field to be in the 2800–3200 km range.