Pi2 pulsations in the inner magnetosphere simultaneously observed by the Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer and Dynamics Explorer 1 satellites
Pi2 pulsations in the inner magnetosphere simultaneously observed by the Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer and Dynamics Explorer 1 satellites
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主动磁层粒子示踪探测器/电荷成分探测器和动力学探测器 1 号卫星同时观测到的内磁层中的 Pi2 脉动
DOI：
10.1029/2010ja016199
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
and P. R. Sutcliffe
中科院分区：
文献类型：
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作者：
Teramoto;M.;K. Takahashi;M. Nose;D.-H. Lee;and P. R. Sutcliffe
我们利用赤道轨道主动磁层粒子示踪探测器 (AMPTE)/电荷成分探测器 (CCE) 和极轨动力学探测器 1 (DE 1) 卫星的磁层以及低纬度站 Kakioka (KAK,L= 1.23) 地面上的磁场观测，统计研究了 Pi2 脉动的空间特征。我们通过对 1984 年 8 月至 1989 年 1 月 KAK 数据的小波分析定义了 Pi2 脉动，并获得了 849 个夜间（20:00–04:00 LT）事件。对于每个 KAK Pi2 事件，我们评估了地面 Pi2 频率下的地面 H 分量与磁层径向 (B⊥R)、方位角 (B⊥A) 和压缩 (B//) 分量之间的相干性。高相干地面卫星 Pi2 事件最常见于 B//，当 CCE 位于赤道附近（磁纬度 <30°）且位于根据经验公式估计的等离子体层顶内部时，其中许多事件在两个航天器上都很明显，而 DE 1 位于高纬度（>30°）且位于估计的等离子体层顶外部。在这些同时发生的 CCE 和 DE 1 事件中，CCE 处的 B// 振幅较大；此外，H-B//交叉相位在CCE处为~0°，但在DE 1处为~180°。我们展示了对一个此类事件以及当CCE位于估计的等离子体层顶之外并在该航天器上表现出不同的相干性和交叉相位特性时发生的另外两个事件的详细分析。总体而言，双卫星观测提供了等离子体层虚拟共振的额外证据，这是之前使用单卫星的研究提出的。
We statistically studied the spatial characteristics of Pi2 pulsations using magnetic field observations in the magnetosphere at the equatorial‐orbiting Active Magnetospheric Particle Tracer Explorers (AMPTE)/Charge Composition Explorer (CCE) and the polar‐orbiting Dynamics Explorer 1 (DE 1) satellites and on the ground at the low‐latitude station Kakioka (KAK,L= 1.23). We defined Pi2 pulsations from wavelet analysis of KAK data covering August 1984 to January 1989 and obtained 849 nightside (20:00–04:00 LT) events. For each KAK Pi2 event, we evaluated the coherence between the groundHcomponent and the magnetospheric radial (B⊥R), azimuthal (B⊥A), and compressional (B//) components at the frequency of the ground Pi2. High‐coherence ground‐satellite Pi2 events were found most often inB//, with many of them evident at both spacecraft when CCE was located near the equator (magnetic latitude <30°) and inside of the plasmapause estimated from an empirical formula while DE 1 was located at high latitude (>30°) and outside of the estimated plasmapause. In these simultaneous CCE and DE 1 events, theB//amplitude was larger at CCE; in addition, theH‐B//cross phase was ∼0° at CCE but was ∼180° at DE 1. We show detailed analysis of one such event as well as two other events that occurred when CCE was outside of the estimated plasmapause and exhibited different coherence and cross‐phase properties at this spacecraft. Overall, the two‐satellite observations provide additional evidence of plasmaspheric virtual resonance, which was previously suggested from studies using single satellites.