A New Approach to Constructing Models of Electron Diffusion by EMIC Waves in the Radiation Belts
A New Approach to Constructing Models of Electron Diffusion by EMIC Waves in the Radiation Belts
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DOI：
10.1029/2020gl088976
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发表时间：
2020-10
影响因子：
5.2
通讯作者：
J. Ross;S. Glauert;R. Horne;C. Watt;N. Meredith;E. Woodfield
中科院分区：
文献类型：
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作者：
J. Ross;S. Glauert;R. Horne;C. Watt;N. Meredith;E. Woodfield
电磁离子回旋（EMIC）波在辐射带中通过共振波-粒子相互作用扩散的相对论电子损失中起着重要作用。我们提出了一种计算反弹和漂移平均EMIC电子扩散系数的新方法。我们使用准线性理论计算反弹平均扩散系数，对于每个单独的联合释放和辐射效应卫星（CRRES）EMIC波观测，使用拟合的波特性，等离子体密度和背景磁场。然后将这些计算结果合并为反弹平均扩散系数。因此，与使用平均光谱和等离子体性质的先前方法相反，所得到的系数捕获单独光谱和等离子体性质的组合效应，从而导致在更宽范围的能量和俯仰角上的扩散。这些计算，以及它们在辐射带模拟中的作用，然后与现有的扩散模型进行比较。新的扩散系数显着改善之间的相对论性电子的衰变计算和货车艾伦探针数据的协议。
Electromagnetic ion cyclotron (EMIC) waves play an important role in relativistic electron losses in the radiation belts through diffusion via resonant wave‐particle interactions. We present a new approach for calculating bounce and drift‐averaged EMIC electron diffusion coefficients. We calculate bounce‐averaged diffusion coefficients, using quasi‐linear theory, for each individual Combined Release and Radiation Effects Satellite (CRRES) EMIC wave observation using fitted wave properties, the plasma density and the background magnetic field. These calculations are then combined into bounce‐averaged diffusion coefficients. The resulting coefficients therefore capture the combined effects of individual spectra and plasma properties as opposed to previous approaches that use average spectral and plasma properties, resulting in diffusion over a wider range of energies and pitch angles. These calculations, and their role in radiation belt simulations, are then compared against existing diffusion models. The new diffusion coefficients are found to significantly improve the agreement between the calculated decay of relativistic electrons and Van Allen Probes data.