CONNECTING THE SUN'S HIGH-RESOLUTION MAGNETIC CARPET TO THE TURBULENT HELIOSPHERE
CONNECTING THE SUN'S HIGH-RESOLUTION MAGNETIC CARPET TO THE TURBULENT HELIOSPHERE
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DOI：
10.1088/0004-637x/767/2/125
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发表时间：
2013-03
期刊：
影响因子：
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通讯作者：
S. Cranmer;A. van Ballegooijen;L. N. Woolsey
中科院分区：
文献类型：
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作者：
S. Cranmer;A. van Ballegooijen;L. N. Woolsey
太阳风通过通量管与太阳大气层相连，通量管植根于太阳表面不断变化的正负磁极模式。观测表明，磁场在很大的空间尺度上是连续的和间歇性的。然而，我们不知道在太阳附近看到的复杂的磁通管拓扑结构在多大程度上随着风扩展到行星际空间而幸存下来。为了研究日冕和日光层之间可能的长距离连接，我们开发了新的模型，顺磁驱动的太阳风加速沿着经验约束的场线。我们使用了一个安静的太阳的势场模型，以前所未有的空间分辨率在它们的脚点追踪场线进入黄道平面。对于每个通量管，创建一个一维模型与现有的波/湍流代码，解决方程的质量，动量和能量守恒从光球到4 Au。考虑到流-流之间的相互作用通量管，我们使用这些模型作为内边界条件的时间稳定的磁流体动力学描述的径向和纵向结构的黄道。共旋流的相互作用涂抹了许多最小尺度的变化，使得很难看到颗粒或超颗粒尺度上的单个通量管如何能够存活到1 Au。然而，我们的模型有助于澄清水平的“背景”的变化与波和湍流涡旋应预期相互作用。此外，磁场幅度的建模波动被认为是相当好地匹配测量的功率谱。
The solar wind is connected to the Sun's atmosphere by flux tubes that are rooted in an ever-changing pattern of positive and negative magnetic polarities on the surface. Observations indicate that the magnetic field is filamentary and intermittent across a wide range of spatial scales. However, we do not know to what extent the complex flux-tube topology seen near the Sun survives as the wind expands into interplanetary space. In order to study the possible long-distance connections between the corona and the heliosphere, we developed new models of turbulence-driven solar wind acceleration along empirically constrained field lines. We used a potential field model of the quiet Sun to trace field lines into the ecliptic plane with unprecedented spatial resolution at their footpoints. For each flux tube, a one-dimensional model was created with an existing wave/turbulence code that solves equations of mass, momentum, and energy conservation from the photosphere to 4 AU. To take account of stream–stream interactions between flux tubes, we used those models as inner boundary conditions for a time-steady magnetohydrodynamic description of radial and longitudinal structure in the ecliptic. Corotating stream interactions smear out much of the smallest-scale variability, making it difficult to see how individual flux tubes on granular or supergranular scales can survive out to 1 AU. However, our models help clarify the level of “background” variability with which waves and turbulent eddies should be expected to interact. Also, the modeled fluctuations in magnetic field magnitude were seen to match measured power spectra quite well.