Null movies

Movies of perturbed 3D null points

1. Shear Motions

Time-varying structure of an axisymmetric null point which is perturbed by applying a shearing field in the fan plane. Note that the field lines in each frame are traced from fixed points in space, and therefore don't show the proper evolution of field lines, but rather give an impression of the changing structure of B in the vicinity of the null. (The points where the field lines change colour in each movie indicate these starting points for the integration of B). The first movie shows a 3D view, and the second shows only a selection of field lines in the xz-plane.

1. Rotational Motions

This time the null point is perturbed by applying perturbation field in the vicinity of the fan plane which takes the form of a rotation (centred on the spine). As before, in each image the field lines are traced from fixed points. This time these points lie in rings in the fan plane (at r=0.2). The first image shows the full 3D view, and in the second image we plot only the field lines in the top half-space, and look down from above.

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