Measurements in the heliosphere and high‐resolution fluid simulations give clear indications for the anisotropy of plasma turbulence in the presence of magnetic fields. How this anisotropy affects transport processes like diffusion and dispersion remains an open question. The first efforts to characterize Lagrangian single‐particle diffusion and two‐particle dispersion in incompressible magnetohydrodynamic (MHD) turbulence were performed a decade ago. We revisit those pioneering results through updated simulations performed at higher Reynolds number. We present new investigations that use the dispersion of many Lagrangian tracer particles to examine the extremes of dispersion and the anisotropy in direct numerical simulations. We then point out directions in which Lagrangian statistics need to be developed to address the fundamental problem of anisotropic MHD turbulence and transport in solar and stellar winds.

中文翻译：

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磁流体动力湍流中色散的拉格朗日统计

日光层的测量和高分辨率流体模拟为存在磁场时等离子体湍流的各向异性提供了清晰的指示。这种各向异性如何影响诸如扩散和分散的传输过程仍然是一个悬而未决的问题。十年前，人们首次做出了表征拉格朗日单粒子扩散和两粒子扩散的不可压缩磁流体动力学（MHD）湍流的研究。我们通过在更高的雷诺数下进行的更新仿真来重新审视那些开创性的结果。我们提出了使用许多拉格朗日示踪剂颗粒的弥散度的新研究，以在直接数值模拟中检查弥散度的极值和各向异性。