Recycling of the Solar Corona’s Magnetic Field
Recycling of the Solar Corona’s Magnetic Field
复制标题
日冕磁场的回收
DOI：
10.1086/424659
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
E. Priest
中科院分区：
文献类型：
--
作者：
R. Close;C. Parnell;D. Longcope;E. Priest
磁场在太阳和其他类太阳恒星的大气层中起着主导作用。在太阳黑子区域之外，所谓的“安静太阳”的光球层包含了无数的小尺度磁浓度，其强度从~1016 Mx到~3 × 1020 Mx不等。这些磁通量集中的不倦运动，以及相反极性磁通量对的不断出现和消失，释放出大量的能量，这些能量可能与太阳日冕的一系列物理过程有关，尤其是日冕加热之谜。我们在这里发现，在安静的太阳日冕中重新绘制磁通量的时间尺度，令人惊讶的是，只有1.4小时（大约是光球通量循环时间的1/10），这意味着安静的太阳日冕比以前认为的要动态得多。除了使我们对太阳日冕中磁驱动现象的起源有更全面的了解外，这样的过程对于理解恒星大气也至关重要。
Magnetic fields play a dominant role in the atmospheres of the Sun and other Sun-like stars. Outside sunspot regions, the photosphere of the so-called quiet Sun contains myriads of small-scale magnetic concentrations, with strengths ranging from the detection limit of ~1016 Mx up to ~3 × 1020 Mx. The tireless motion of these magnetic flux concentrations, along with the continual appearance and disappearance of opposite-polarity pairs of fluxes, releases a substantial amount of energy that may be associated with a whole host of physical processes in the solar corona, not least the enigma of coronal heating. We find here that the timescale for magnetic flux to be remapped in the quiet-Sun corona is, surprisingly, only 1.4 hr (around 1/10 of the photospheric flux recycling time), implying that the quiet-Sun corona is far more dynamic than previously thought. Besides leading to a fuller understanding of the origins of magnetically driven phenomena in our Sun's corona, such a process may also be crucial for the understanding of stellar atmospheres in general.