Morton R J, Mooroogen K, Henriques V M J
Department of Mathematics, Physics and Electrical Engineering, Northumbria University, Newcastle Upon Tyne NE1 8ST, UK.
Institute of Theoretical Astrophysics, and.
Philos Trans A Math Phys Eng Sci. 2021 Feb 8;379(2190):20200183. doi: 10.1098/rsta.2020.0183. Epub 2020 Dec 21.
Sunspots have played a key role in aiding our understanding of magnetohydrodynamic (MHD) wave phenomena in the Sun's atmosphere, and it is well known they demonstrate a number of wave phenomena associated with slow MHD modes. Recent studies have shown that transverse wave modes are present throughout the majority of the chromosphere. Using high-resolution Ca II 8542 Å observations from the Swedish Solar Telescope, we provide the first demonstration that the chromospheric super-penumbral fibrils, which span out from the sunspot, also show ubiquitous transverse motions. We interpret these motions as transverse waves, in particular the MHD kink mode. We compile the statistical properties of over 2000 transverse motions to find distributions for periods and amplitudes, finding they are broadly consistent with previous observations of chromospheric transverse waves in quiet Sun fibrils. The very presence of the waves in super-penumbral fibrils raises important questions about how they are generated, and could have implications for our understanding of how MHD wave energy is transferred through the atmosphere of a sunspot. This article is part of the Theo Murphy meeting issue 'High-resolution wave dynamics in the lower solar atmosphere'.
太阳黑子在帮助我们理解太阳大气中的磁流体动力学（MHD）波现象方面发挥了关键作用，众所周知，它们展示了许多与慢磁流体动力学模式相关的波现象。最近的研究表明，横向波模式存在于色球层的大部分区域。利用瑞典太阳望远镜的高分辨率钙 II 8542 Å 观测数据，我们首次证明了从太阳黑子延伸出来的色球超半影纤维也显示出普遍存在的横向运动。我们将这些运动解释为横向波，特别是磁流体动力学扭结模式。我们汇编了2000多次横向运动的统计特性，以找到周期和振幅的分布，发现它们与之前在宁静太阳纤维中对色球横向波的观测大致一致。超半影纤维中波的存在引发了关于它们如何产生的重要问题，并且可能对我们理解磁流体动力学波能量如何通过太阳黑子大气传输产生影响。本文是西奥·墨菲会议议题“太阳低层大气中的高分辨率波动力学”的一部分。
