Results from the weak-field MURaM simulation at half-minute intervals, ordered along columns. The grey scale in the horizontal planes shows the vertical component of the magnetic field at the geometrical height where ⟨ τ ⟩ = 0.1. The third sample is enlarged for better visibility. Green denotes volume rendering of temperature in the range T = 5700−6500 K and outlines the site with most ohmic heating. Some magnetic field lines are shown in the middle panel, colour-coded according to vertical gas velocity (downflows red, upflows blue). The sequence illustrates that the cancellation of opposite-polarity field concentrations produces heated features with EB-like behaviour.