太阳大气中有限振幅磁场扰动的动力学过程

本文从完整的磁流体动力学方程组出发,通过太阳大气中磁力线管根部有限振幅磁场的扰动,研究了非线性磁场的动力学演化。假设初始磁场位形足β<<1的势场,根部磁力线管磁场扰动,驱动等离子体运动,一部分磁能转换为等离子体动能。等离子体压缩运动具有快磁声波的特性。计算结果给出非线性磁场演化的定量关系,可以解释太阳大气中日冕活动过程。也可用于模拟实验室里高β实验装置中的等离子体的持性。 

MAGNETOHYDRODYNAMIC BEHAVIOUR OF DISTURBANCE OF FINITE AMPLITUDE MAGNETIC FIELD IN THE SOLAR ATMOSPHERE

In this paper,dynamic processes in the solar atmosphere are studied numerically from a complete set of MHD equations.Dynamic evolution of nonlinear magnetic field is produced by the finite amplitude of the azimuthal magnetic field at the base of the flux tube of the solar atmosphere.It is assumed that the initial configuration of the magnetic field is a force-free and potential field,the magnetic field is disturbed at the base,the plasma is driven and a part of magnetic energy is transformed into the kinetic energy of the plasma.The compressed flow of the plasma has the features of fast MHD waves.The computation results give quantitatively the nonlinear evolution of strong magnetic fields.These results could apply to the explanation of coronal transients,surge,spray and eruptive prominence events in the solar atmosphere,and to the modelling of plasma behaviour in high-βstructure experiments in the laboratory as well.