摘要
本文作者用北京天文台怀柔太阳观测站的太阳磁场望远镜对黑子活动区进行了连续五天的观测,获得了精细结构的一些明显特征.本文从磁扩散率是温度的函数出发,通过感应方程中的扩散项是温度与磁场的相互作用关系,探讨了精细结构的成因.利用小扰动线性化磁流力学方程组的办法,获得了小扰动不稳定模式.因此,它使原来较平坦的稳定磁场出现了不均匀结构,这就是太阳活动区磁场、亮度场在磁扩散过程中出现精细结构与纤维组织的原因.它们是磁场扩散的一种必然形式. 我们观测到的纤维大小约1~″.5至3~″,对应于太阳上约1000公里至2000公里的距离,而利用太阳黑子的一些典型参数可以估计出精细结构的尺度下限达到220公里的量级,这与目前观测上所估计的数值相一致.
We utilized the solar magnetic field telescope in Huairou Solar Observation Station of Beijing Obesrvatory for five days to observe the features of the solar active regions and obtained some conspicuous characteristics of the fine structures in solar active regions. In this paper, we discussed the cause of the fine structure of magnetic fields in solar active region based on the magnetic diffusion instability. The diffusion term in the induction equation represents also the interaction between the temperature and magnetic field because that the magnetic diffusivity is a function of temperature. We obtained the perturbation instability mode in the hydromagnetic perturbation equations with the above consideration. This magnetic diffusion instability causes non-uniform structure of with the above consideration. This magnetic diffusion instability causes non-uniform structure magnetic field in the solar active regions in where previous smooth magnetic field is stayed. This is the reason for appearance of the fine structure and the filamenes of magnetic field in solar active regions that is a inevitable form of magnetic diffusion during the process of magnetic diffusion in the hydromagnetic fluid. The scales of filaments in our observation(?) are about 1.5″ to 3″ and the corresponding distance on the solar surface are about 1000 Km to 2000 Km. It may be to estimate the lower limit of the scale of fine structure to be about 220 Km from magnetic diffusion instability mode with some typical parameters of sunspots. At present, this value is consistent with the value of estimation by observation.
出处
《天文学报》
CSCD
北大核心
1989年第2期194-207,共14页
Acta Astronomica Sinica
基金
国家自然科学基金~~
