Three‐dimensional MHD modeling of the global corona throughout solar cycle 23
Three‐dimensional MHD modeling of the global corona throughout solar cycle 23
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DOI：
10.1029/2007ja012750
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发表时间：
2008-03
影响因子：
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通讯作者：
Yingzhou Hu;X. Feng;S. Wu;Wenzhi Song
中科院分区：
文献类型：
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作者：
Yingzhou Hu;X. Feng;S. Wu;Wenzhi Song
[1]基于时空守恒元和解元（CESE）方法，我们最近发展了一个新的三维磁流体动力学（MHD）模型，用于日冕和行星际研究。本文的目的是利用Wilcox太阳天文台（WSO）观测到的视线光球磁场作为边界条件，描述这种新的MHD模型在研究全球日冕磁结构中的应用。利用该模型，计算了23周15个卡林顿自转（CR）的日冕磁场结构。结果表明，在太阳活动周的过程中，日球电流片（HCS）的形状和位置以及日冕磁场结构是如何演变的。通过与标准位场源面（PFSS）模型计算结果的比较，并结合白光观测，进一步验证了新的MHD模型的正确性。从MHD和PFSS模型计算的源表面中性线通常彼此匹配密切，但是，差异发生在不同的阶段，在太阳活动周期。HCS的位置显示出良好的整体协议与所观察到的白光强度图案中的明亮的结构，特别是在太阳极小期或太阳极大期后，这一结果证实，所观察到的白光流光结构起源于一个单一的，大规模的等离子体片位于附近的HCS。
[1] Based on the space-time conservation element and solution element (CESE) method, we have recently developed a novel 3D magnetohydrodynamic (MHD) model for the solar corona and interplanetary study. Our aim here is to describe the application of this new MHD model to study the global coronal magnetic structures by using the observed line-of-sight photospheric magnetic field from the Wilcox Solar Observatory (WSO) as boundary conditions. With this model, the magnetic structures of the global corona are obtained for fifteen Carrington Rotations (CRs) spanning solar cycle 23. The results illustrate how the shape and location of the heliospheric current sheet (HCS) and the coronal magnetic field configuration evolve during the course of the solar cycle. Comparison between our numerical results for the coronal magnetic structures and those from the standard potential field source surface (PFSS) model, with, in addition, white-light observations further validates this new MHD model. The source surface neutral lines calculated from the MHD and PFSS models generally match each other closely; however, differences occur at different phases in the solar cycle. The location of the HCS shows good overall agreement with the bright structures in the observed white-light intensity pattern, especially around solar minimum or well after solar maximum, and this result confirms that the observed white-light streamer structures originate from a single, large-scale plasma sheet located near the HCS.