THEMIS observations of electron cyclotron harmonic emissions, ULF waves, and pulsating auroras
THEMIS observations of electron cyclotron harmonic emissions, ULF waves, and pulsating auroras
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DOI：
10.1029/2009ja015148
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发表时间：
2010-10
影响因子：
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通讯作者：
Jun Liang;V. Uritsky;E. Donovan;B. Ni;E. Spanswick;T. Trondsen;J. Bonnell;A. Roux;U. Auster
中科院分区：
文献类型：
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作者：
Jun Liang;V. Uritsky;E. Donovan;B. Ni;E. Spanswick;T. Trondsen;J. Bonnell;A. Roux;U. Auster
[1]我们提出了多探头，多仪器观测的电子回旋谐波（ECH）的排放量和超低频（ULF）波的时间历史的事件和大尺度相互作用在亚暴（THEMIS），并探讨其潜在的联系，同时地面观测脉动极光（PSA）在2009年1月4日。ECH的排放量被观察到作为离散包调制的超低频拍动的中性片周围的探头。结合不同的ECH观测数据，我们推断ECH的发射强度是强烈起伏的，并包含多时间尺度的精细结构。PsA补丁的分布特征纵向“波长”在演唱会现场ULF波的特征推断从交叉相位分析。PsA的整体活性与原位测量的高能电子通量和ECH波强度相关。我们认为，ECH波发挥了关键作用，在俯仰角扩散的等离子体片电子，导致PsA，而超低频波结构的等离子体片，并施加宏观影响的空间分布的PsA。
[1] We present multiprobe, multi-instrument observations of the electron cyclotron harmonic (ECH) emissions and ultralow-frequency (ULF) waves from Time History of Events and Macroscale Interactions during Substorms (THEMIS) and explore their potential linkage to the concurrent ground-observed pulsating auroras (PsA) on 4 January 2009. The ECH emissions were observed as discrete packets modulated by the ULF flapping motion of the neutral sheet around the probes. Combining different data sets of the ECH observations, we infer that the ECH emission intensities were strongly fluctuating and contained multi-time scale fine structures. The distribution of PsA patches featured longitudinal “wavelength” in concert with the in situ ULF wave characteristics inferred from a cross-phase analysis. The overall activeness of the PsA correlated with the in situ-measured energetic electron fluxes and ECH wave intensities. We suggest that ECH waves played the key role in the pitch angle diffusion of the plasma sheet electrons that led to the PsA, while the ULF waves structured the plasma sheet and imposed a macroscopic effect over the spatial distribution of the PsA.