Three-dimensional views of the longitudinal velocity in the rotating frame. Red are the positive velocities, and blue the negative velocities. Picture a) is the initial time where we added the magnetic field, and picture b) is taken after two solar rotation periods. Picture c) is taken much later in the simulation, when the magnetic layer became stable. Colored lines are the magnetic field lines we constructed from only a few seed points to be able to distinguish them. Dark colors denote lower magnetic field intensity. Note that for the third image, we only put in seed points at one longitude value to distinguish the field lines that explore almost the entire ϕ domain in the radiation zone.