摘要
在黑子半影电流的磁场中存在扰动不稳定模式,本文认为黑子半影纤维是由这种不稳定扰动发展而形成的,利用短波近似,分别在黑子半径方向及围绕黑子方向上求解非绝热慢波色散方程。由不稳定条件可得到(1)纤维的长度与宽度的数值;(2)纤维模式在长度方向上是静止的,在宽度方向上几乎是不动的;(3)半影纤维是黑子在重力场中的磁流特征之一;(4)半影纤维的出现,表示着黑子扭转磁场的存在。
Using short wave approximation, we have solved magnotohydrodynamic disturbance equation including Joule heating and thermal conduction. It is possible that the penumbral filament structure results from the development of instability in the magnetic field of penumbral current. It is found that (1) there are two lower limits of penumbral filament width anl length according to the instability condition respectively; (2) there is no overstable state mode propagating along the filaments and it is a very near non-overstable state mode propagating normal to the filaments; (3) the penumbral filament is related to the gravitation; (4) the magnetic field of sunspot is twisted when penumbral structure appears.
