CIRC: (a) and (b) magnetic field lines (closed, magenta; open, blue) viewed in the xz-plane at y = 9 Mm, at t = 30 (0.6 rotations) and t = 120 time steps (2.4 rotations). (c) Free magnetic energy (black) and height of null point (red) as a function of time. (d) Logarithm of current, viewed in the xz-plane at y = 15 Mm, at t = 120 time steps (2.4 rotations). An animation of the magnetic field lines viewed in the xz-plane at y = 9 Mm (left panel) and the logarithm of the current, viewed in the xz-plane at y = 15 Mm (right panel) evolving from time step 0 to 200 are provided online.

(An animation of this figure is available.)

The video/animation of this figure is available in the online journal.