摘要
在以无力磁场的非势特征近似描述磁剪切位形时,无力因子α即可做为磁剪切的量度;而磁剪切的发展则为方程所解析描述.这里G=B/t×B,可称为磁剪切产生函数.该方程表明,磁剪切产生于局地的发电机作用,是磁场与磁流体运动相互作用的结果.相反极性磁结构的挤压,磁通量的浮现与下沉,都可以和剪切运动一样,有效地导致磁剪切的发展.
In view of the approximate description of magnetic shear configuration by a force-free magnetic field, the force-free factor a would be a measure of magnetic shear, and its time changes would be analytically described by a differential equationwhere, G = B/t × B, might be called as the generation function of magnetic shear.dtIt is clearly shown by this equation that the magnetic shear is generated by local dynamo action resulting from the interaction between magnetic field and plasma motion. It is also illustrated that the emergence and submergence of magnetic flux and the squeezing and pressing of the opposite polarity fields would be as effective as shear motion in producing the magnetic shear.
基金
国家自然科学基金
中国科学院重大项目资助
关键词
太阳物理
磁场
磁剪切
Sun-magnetic field-magnetic shear
