论文标题
使用数值模拟研究简单通量管的表面影响
Investigation of surface effects of simple flux tubes using numerical simulations
论文作者
论文摘要
我们将SPARC代码用于具有不同地下拓扑的单片通量管的MHD模拟。我们的研究涉及由单个源与地下磁场引起的波的相互作用。以前已经描述了沿通量管向下滴入声音的模式转换，并且可以在我们的模拟中进行可视化。我们表明，这种向下的繁殖导致通量管充当孤立的来源，从而产生了特征性的表面波场。测量表面的波场揭示了磁场拓扑的地下特性。使用时间距离的气旋学，我们演示了如何基于$ \ vardelta $ \ vardelta t = 282.6 $ sec的集体旅行时间延迟来检测如何检测到由于波数据包花费时间地下作为慢模式波。尽管幅度很小，并且通常被全波场叠加，但如果做出了约$ \ vardelta t $的假设，则可以检测到。我们为使用太阳能来源的模拟演示了这一点。这类研究有可能根据表面信号的分析揭示黑子的地下信息。
We use the SPARC code for MHD simulations with monolithic flux tubes of varying subsurface topology. Our studies involve the interactions of waves caused by a single source with subsurface magnetic fields. Mode conversion causing acoustic power to trickle downwards along the flux tube has been described before and can be visualized in our simulations. We show that this downward propagation causes the flux tube to act as an isolated source, creating a characteristic surface wavefield. Measuring this wavefield at the surface reveals subsurface properties of the magnetic field topology. Using time distance helioseismology, we demonstrate how to detect such a flux tube signal based on a group travel-time delay of $\varDelta t = 282.6$ sec due to the wave packet spending time subsurface as a slow mode wave. Although the amplitude is small and generally superimposed by the full wave field, it can be detected if assumptions about $\varDelta t$ are made. We demonstrate this for a simulation with solar like sources. This kind of study has the potential to reveal subsurface information of sunspots based on the analysis of a surface signal.
