Narrow lanes of transverse magnetic field in sunspots
Narrow lanes of transverse magnetic field in sunspots
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DOI：
10.1038/363426a0
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发表时间：
1993-06
期刊：
影响因子：
64.8
通讯作者：
H. Zirin;H. Wang
中科院分区：
文献类型：
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作者：
H. Zirin;H. Wang
太阳耀斑与太阳表面的磁场活动密切相关。它们通常出现在复杂的太阳黑子群中，那里的垂直磁场突然反转，连接垂直两极的水平（横向）磁场既被剪切又很强。一条场反转线可能是许多耀斑的发生地。在这里，我们报告了一个大的，活跃的太阳黑子群，揭示了一系列方向相反的垂直场反转分离的极窄的细长通道的强烈的水平场的观测。在能量最小的配置中，连接方向相反的垂直场的磁力线只是横跨反转线;但是当新出现的太阳黑子穿过旧的磁场配置时，两极被推到一起，磁力线沿着反转线沿着急剧转向，与一段距离外的垂直场重新连接。这些水平场的多个通道意味着一个大的旋度项（λ ×B），因此意味着一个相当大的电流。我们的观测结果表明，几乎所有的大耀斑在这个地区发生在这些高度回旋的领域。
SOLAR flares are closely associated with magnetic activity on the surface of the Sun. They typically occur1in complex sunspot groups, where the vertical magnetic fields reverse abruptly, and the horizontal (transverse) fields connecting the vertical poles are both sheared and strong. A single field inversion line may be the site of many flares1. Here we report observations of a large, active sunspot group which reveal a series of oppositely directed vertical-field inversions separated by extremely narrow elongated channels of intense horizontal fields. In a minimum-energy configuration, lines of force connecting oppositely directed vertical fields simply arch across the inversion line; but when newly emerged sunspots move through older magnetic-field configurations, the poles are pushed together and the field lines turn sharply along the inversion line to reconnect with the vertical field some distance away. These multiple channels of horizontal field imply a large curl term (▿×B), and hence a substantial electric current. Our observations show that almost all of the larger flares in this region occur in these highly convoluted fields.