The rapid motion of filaments in active regions - Field-aligned current

It was shown previously that the equilibrium (linear) current in an external potential field can lead to the rapid motion of a filament due to a loss in stability. In the present paper, consideration is given to a field which can be treated either as a loop system or as a rope in an external potential field. The field arises due to displacement-type motion and the simultaneous shifting of the plasma from the line of field-polarity change. The current above the plane of the photosphere continuously rises because of this motion. The configuration is characterized by the following three parameters: the external homogeneous field, the radius of the rope, and the angle between the axis of the rope and the direction of the external field. This is a new solution to the fff equations and the new model of the confinement of a filament in equilibrium.