Three-dimensional MHD modeling of waves in active region loops
Three-dimensional MHD modeling of waves in active region loops
复制标题
活动区域环路中波的三维 MHD 建模
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
M. Selwa
中科院分区：
文献类型：
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作者：
L. Ofman;M. Selwa
摘要观测表明，MHD波是日光层中最重要的普遍过程之一。这些波很可能在日光层的能量传递中发挥重要作用，并且它们可以用作局部磁流体环境特性的诊断工具。TRACE和Hinode卫星最近的观测提供了日冕活动区环振荡的充分证据。振荡被解释为快（扭结）、慢和阿尔文模式，波的特性被用于日冕地震学。然而，由于非均匀活动区等离子体中各种模式的复杂相互作用，以及由于非线性，理想化的线性理论不足以正确地描述波。为了克服这一理论上的缺陷，我们开发了三维MHD模型中的活动区环波。我们研究了三维活动区磁场和密度结构对振荡和波耗散的影响，并研究了单个环的振荡。有些环被构造成包含几个线程和扭曲。在这里，我们提出了我们的模型的结果，并展示了如何使用它们来更好地理解波的属性，和活动区域。
Abstract Observations show that MHD waves are one of the most important universal processes in the heliosphere. These waves are likely to play an important role in energy transfer in the heliosphere, and they can be used as a diagnostic tool of the properties of the local magneto-fluid environment. Recent observations by TRACE and Hinode satellites provide ample evidence of oscillations in coronal active region loops. The oscillations were interpreted as fast (kink), slow, and Alfvén modes, and the properties of the waves were used for coronal seismology. However, due to the complex interactions of the various modes in the inhomogeneous active region plasma, and due to nonlinearity, idealized linear theory is inadequate to properly describe the waves. To overcome this theoretical shortcoming we developed 3D MHD models of waves in active region loops. We investigated the effects of 3D active region magnetic and density structure on the oscillations and the wave dissipation, and we investigated the oscillation of individual loops. Some loops were constructed to contain several threads and twist. Here, we present the results of our models, and show how they can be used to understand better the properties of the waves, and of the active regions.