Maps of vertical magnetic field gradients measured directly from the model and reconstructed using BSG. The left, middle, and right panels are for snapshots A, B, and C, respectively. Panels a–c: show real gradients (measured from the MHD model), and panels d–f show constructed field gradient values. The colour scale is in units of 10⁻³ G m⁻¹. Magnetic field gradient values on panels d–f are calculated only for pixels with magnetic field |B| > 100 G.