Woods L C, Ashbourn J M
Mathematical Institute, University of Oxford, 24-29 St. Giles', Oxford OX1 3LB, England.
Phys Rev Lett. 2000 Apr 24;84(17):3748-51. doi: 10.1103/PhysRevLett.84.3748.
We show that a magnetic flux tube can grow in strength and size provided the temperature increases outward at the edge of the tube where the axial magnetic field declines to its external value. The radius of the tube increases at a rate determined by our theory. It is the coincidence of temperature and magnetic field gradients of opposite sign that generates the new field, and if this is lost the tube ceases to grow. The phenomenon is illustrated by adopting plausible distributions for the temperature and magnetic field strength, which yield an expression for the rate of growth of the magnetic field magnitude B. The mechanism provides a possible explanation of the fibrous nature of solar magnetic fields.
我们表明，只要在磁通量管边缘处温度向外升高，且轴向磁场在此处降至其外部值，磁通量管就能在强度和尺寸上增长。磁通量管的半径以我们的理论所确定的速率增加。正是温度和磁场梯度符号相反的巧合产生了新磁场，若这种巧合消失，磁通量管就会停止增长。通过采用温度和磁场强度的合理分布来说明这一现象，这些分布得出了磁场强度B的增长率表达式。该机制为太阳磁场的纤维状性质提供了一种可能的解释。
