Evaluation of Plasma Properties From Chorus Waves Observed at the Generation Region
Evaluation of Plasma Properties From Chorus Waves Observed at the Generation Region
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根据在生成区域观察到的合唱波评估等离子体特性
DOI：
10.1029/2018ja026337
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Friedel Reinhard H.
中科院分区：
文献类型：
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作者：
Juh?sz Lilla;Omura Yoshiharu;Lichtenberger J?nos;Friedel Reinhard H.
在这项研究中，我们提出了一种反演方法，提供热等离子体人口参数的合唱团发射的特点。我们的最终目标是将这种方法应用于地面数据，以获得许多辐射带模型的低能边界条件。第一步是在生成区的货车艾伦探针的原位数据上测试合唱反演方法。高能电子的密度和热速度（几千电子伏到100千电子伏）是通过分析货车艾伦探测器上的电磁场仪器套件和综合科学的波数据，从频率扫描速率和合唱发射的起始频率推导出来的。Omura和纳恩（2011，https：//doi.org/10.1029/2010JA016280）的非线性波增长理论作为我们反演方法的基础，假设触发波起源于线性回旋不稳定性。我们呈现了2012年11月14日11和12 UT之间在发电区记录的16个连续上升音发射。反演的结果与来自氦、氧、质子和电子仪器的单向通量数据的高能电子的密度和热速度（平行和垂直）进行了比较，显示出良好的一致性：测量值和预测值之间的归一化均方根偏差小于± 15%。我们发现，理论振幅与实测振幅一致。线性和非线性波浪增长之间的关系符合我们的基本假设，即线性增长是非线性波浪增长的前一个过程。我们分析了在相对论共振能量范围内的电子分布。
In this study we present an inversion method which provides thermal plasma population parameters from characteristics of chorus emissions only. Our ultimate goal is to apply this method to ground‐based data in order to derive the lower‐energy boundary condition for many radiation belt models. The first step is to test the chorus inversion method on in situ data of the Van Allen Probes in the generation region. The density and thermal velocity of energetic electrons (few kiloelectron volts to 100 keV) are derived from frequency sweep rate and starting frequencies of chorus emissions through analysis of wave data from the Electric and Magnetic Field Instrument Suite and Integrated Science on board the Van Allen Probes. The nonlinear wave growth theory of Omura and Nunn (2011, https://doi.org/10.1029/2010JA016280) serves as the basis for our inversion method, assuming that the triggering wave is originated by the linear cyclotron instability. We present 16 consecutive rising‐tone emissions recorded in the generation region between 11 and 12 UT on 14 November 2012. The results of the inversion are compared with density and thermal velocities (parallel and perpendicular) of energetic electrons derived from the unidirectional flux data of the Helium, Oxygen, Proton, and Electron instrument, showing a good agreement: The normalized root‐mean‐square deviation between the measured and predicted values are less than ∼15%. We found that the theoretical amplitudes are consistent with the measured ones. The relation between linear and nonlinear wave growth agrees with our basic assumption; namely, linear growth is a preceding process of nonlinear wave growth. We analyze electron distributions at the relativistic resonant energy ranges.