Hori K, Nilsson A, Tobias S M
Graduate School of System Informatics, Kobe University, Rokkodai 1-1, Nada, Kobe, 657-8501 Japan.
Department of Geology, Lund University, Sölvegatan 12, Lund, 22362 Sweden.
Rev Mod Plasma Phys. 2023;7(1):5. doi: 10.1007/s41614-022-00104-1. Epub 2022 Dec 26.
This Special Topic focuses on magnetohydrodynamic (MHD) processes in the deep interiors of planets, in which their fluid dynamos are in operation. The dynamo-generated, global, magnetic fields provide a background for our solar-terrestrial environment. Probing the processes within the dynamos is a significant theoretical and computational challenge and any window into interior dynamics greatly increases our understanding. Such a window is provided by exploring rapid dynamics, particularly MHD waves about the dynamo-defined basic state. This field is the subject of current attention as geophysical observations and numerical modellings advance. We here pay particular attention to torsional Alfvén waves/oscillations and magnetic Rossby waves, which may be regarded as typical axisymmetric and nonaxisymmetric modes, respectively, amongst a wide variety of wave classes of rapidly rotating MHD fluids. The excitation of those waves has been evidenced for the Earth - whilst their presence has also been suggested for Jupiter. We shall overview their dynamics, summarise our current understanding, and give open questions for future perspectives.
本专题聚焦于行星深部内部的磁流体动力学（MHD）过程，在这些过程中行星的流体发电机在运转。发电机产生的全球磁场为我们的日地环境提供了一个背景。探究发电机内部的过程是一项重大的理论和计算挑战，而任何洞察内部动力学的窗口都能极大地增进我们的理解。通过探索快速动力学，特别是围绕发电机定义的基本状态的磁流体动力学波，就提供了这样一个窗口。随着地球物理观测和数值模拟的进展，这个领域成为当前关注的主题。我们在此特别关注扭转阿尔文波/振荡和磁罗斯比波，它们在快速旋转的磁流体动力学流体的各种波类中，可分别被视为典型的轴对称和非轴对称模式。这些波的激发在地球上已得到证实——而在木星上也有人提出它们的存在。我们将概述它们的动力学，总结我们目前的理解，并提出未来展望的开放性问题。
