NONLINEAR PROPAGATION OF ALFVEN WAVES DRIVEN BY OBSERVED PHOTOSPHERIC MOTIONS: APPLICATION TO THE CORONAL HEATING AND SPICULE FORMATION
NONLINEAR PROPAGATION OF ALFVEN WAVES DRIVEN BY OBSERVED PHOTOSPHERIC MOTIONS: APPLICATION TO THE CORONAL HEATING AND SPICULE FORMATION
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DOI：
10.1088/0004-637x/710/2/1857
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发表时间：
2010-02-20
影响因子：
4.9
通讯作者：
Shibata, Kazunari
中科院分区：
文献类型：
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作者：
Matsumoto, Takuma;Shibata, Kazunari
我们对阿尔文波在太阳大气中沿开放磁通管的传播进行了磁流体动力学模拟。在我们的数值模型中，阿尔文波是由光球层的米粒运动产生的。作为波源，我们使用了从“日出”号太阳光学望远镜的G波段影片中推导出的光球层米粒运动的时间频谱。结果表明，当我们使用观测到的频谱而非白/粉红噪声频谱作为波源时，日冕处的总能量通量更大，过渡区的高度更高。这种差异可以用光球层和过渡区之间的阿尔文波共振来解释。在对我们的数值结果进行傅里叶分析之后，我们发现光球层和过渡区之间的区域成为一个阿尔文波共振腔。我们已经确认在我们的数值模型中至少存在三个共振频率，分别为1、3和5毫赫兹。阿尔文波共振是解释针状体动力学以及为加热日冕提供足够能量通量的最有效机制之一。
We have performed MHD simulations of Alfven wave propagation along an open flux tube in the solar atmosphere. In our numerical model, Alfven waves are generated by the photospheric granular motion. As the wave generator, we used a derived temporal spectrum of the photospheric granular motion from G-band movies of Hinode/Solar Optical Telescope. It is shown that the total energy flux at the corona becomes larger and the transition region's height becomes higher in the case when we use the observed spectrum rather than the white/pink noise spectrum as the wave generator. This difference can be explained by the Alfven wave resonance between the photosphere and the transition region. After performing Fourier analysis on our numerical results, we have found that the region between the photosphere and the transition region becomes an Alfven wave resonant cavity. We have confirmed that there are at least three resonant frequencies, 1, 3, and 5 mHz, in our numerical model. Alfven wave resonance is one of the most effective mechanisms to explain the dynamics of the spicules and the sufficient energy flux to heat the corona.