Time evolution for both the volume-averaged magnetic field component, ⟨B_y⟩ (first image) and the magnetic stress-to-pressure ratio, r_sp = ⟨ − 2B_xB_y⟩/⟨|B|²⟩ (second image). Simulation gi-mri-res-1 is depicted as the dashed red curve, and gi-mri-res-2 is shown as the black curve. For reference, the value r_sp = 0.3 is shown as the horizontal dashed line in the second image. The vertical, dashed, and dotted lines mark the time points when the seed fields are introduced.