Solanki S K, Schüssler M, Fligge M
Max-Planck-Institut für Aeronomie, Katlenburg-Lindau, Germany.
Nature. 2000 Nov 23;408(6811):445-7. doi: 10.1038/35044027.
The most striking feature of the Sun's magnetic field is its cyclic behaviour. The number of sunspots, which are dark regions of strong magnetic field on the Sun's surface, varies with a period of about 11 years. Superposed on this cycle are secular changes that occur on timescales of centuries and events like the Maunder minimum in the second half of the seventeenth century, when there were very few sunspots. A part of the Sun's magnetic field reaches out from the surface into interplanetary space, and it was recently discovered that the average strength of this interplanetary field has doubled in the past 100 years. There has hitherto been no clear explanation for this doubling. Here we present a model describing the long-term evolution of the Sun's large-scale magnetic field, which reproduces the doubling of the interplanetary field. The model indicates that there is a direct connection between the length of the sunspot cycle and the secular variations.
太阳磁场最显著的特征是其周期性行为。太阳黑子是太阳表面强磁场的暗区，其数量以约11年的周期变化。叠加在这个周期之上的是发生在数百年时间尺度上的长期变化，以及像17世纪下半叶蒙德极小期那样几乎没有太阳黑子的事件。太阳磁场的一部分从表面延伸到行星际空间，最近发现这个行星际磁场的平均强度在过去100年里增加了一倍。迄今为止，对于这种翻倍现象还没有明确的解释。在此，我们提出一个描述太阳大规模磁场长期演化的模型，该模型再现了行星际磁场的翻倍现象。该模型表明，太阳黑子周期的长度与长期变化之间存在直接联系。
