Electron Landau damping of kinetic Alfvén waves in simulated magnetosheath turbulence
Electron Landau damping of kinetic Alfvén waves in simulated magnetosheath turbulence
复制标题
模拟磁鞘湍流中动能阿尔文波的电子朗道阻尼
DOI：
10.1063/5.0021727
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发表时间：
2020
影响因子：
2.2
通讯作者：
A. McCubbin
中科院分区：
文献类型：
--
作者：
Sarah A. Horvath;G. Howes;A. McCubbin
湍流被认为在太阳风等离子体的加热过程中发挥了作用，尽管在日球层中驱动这一过程的机制的确切性质仍有许多问题有待解决。特别是，在湍流级联的动力学耗散范围内，粒子与湍流电磁场之间的无碰撞相互作用的物理性质仍然不完全清楚。最近对磁层多尺度（MMS）观测的一段时间的分析使用场-粒子相关技术证明了电子朗道阻尼参与了地球磁鞘湍流的耗散。基于这一发现，我们对MMS区间的湍流进行了高分辨率的陀螺动力学数值模拟，以研究电子朗道阻尼在湍流能量耗散中的作用。我们对模拟数据采用场-粒子相关技术，将我们的结果与已知的朗道阻尼在耗散范围外的速度空间特征进行比较，并评估净电子能量。我们发现在能量的一些关键方面，数值和观测结果之间的定性一致，并根据实验因素推测分歧的性质，例如分辨率的差异，以及在色散动力学Alfven波存在时发展对场-粒子相互作用性质的见解。
Turbulence is thought to play a role in the heating of the solar wind plasma, though many questions remain to be solved regarding the exact nature of the mechanisms driving this process in the heliosphere. In particular, the physics of the collisionless interactions between particles and turbulent electromagnetic fields in the kinetic dissipation range of the turbulent cascade remains incompletely understood. A recent analysis of an interval of Magnetospheric Multiscale (MMS) observations has used the field–particle correlation technique to demonstrate that electron Landau damping is involved in the dissipation of turbulence in the Earth's magnetosheath. Motivated by this discovery, we perform a high-resolution gyrokinetic numerical simulation of the turbulence in the MMS interval to investigate the role of electron Landau damping in the dissipation of turbulent energy. We employ the field–particle correlation technique on our simulation data, compare our results to the known velocity–space signatures of Landau damping outside the dissipation range, and evaluate the net electron energization. We find qualitative agreement between the numerical and observational results for some key aspects of the energization and speculate on the nature of disagreements in light of experimental factors, such as differences in resolution, and of developing insights into the nature of field–particle interactions in the presence of dispersive kinetic Alfven waves.
影响因子：
4.9
作者：
Chen, C. H. K.;Boldyrev, S.
通讯作者：
Boldyrev, S.