论文标题

模拟的磁盘湍流中的动力学alfvén波的电子兰道阻尼

Electron Landau Damping of Kinetic Alfvén Waves in Simulated Magnetosheath Turbulence

论文作者

Horvath, Sarah A., Howes, Gregory G., McCubbin, Andrew J.

论文摘要

人们认为湍流在加热太阳风血浆中发挥作用,尽管关于在Heliosphere中推动这一过程的机制的确切性质仍有待解决。特别是,在湍流级联反应的动力学耗散范围内,颗粒与湍流电磁场之间无碰撞相互作用的物理学仍然尚不完全理解。最近对磁层多尺度(MMS)观测的间隔进行了分析,已使用现场粒子相关技术,以证明电子Landau阻尼与地球磁珠中湍流的耗散有关。在这一发现的驱动下,我们对MMS间隔中的湍流进行了高分辨率的陀螺数值模拟,以研究电子兰道阻尼在湍流耗散中的作用。我们在模拟数据上采用了现场粒子相关技术,将结果与耗散范围之外的Landau阻尼的已知速度空间特征进行比较,并评估净电子能量。我们发现,对于能量的某些关键方面的数值和观察结果之间的定性一致性,并根据实验因素(例如分辨率的差异)以及在存在分散动力学的ALFVUN波中对分歧的性质进行推测。

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 Magnetosphere 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 Alfvén waves.

扫码加入交流群

加入微信交流群

微信交流群二维码

扫码加入学术交流群,获取更多资源