Top panel: height variation of the temperature along the slice corresponding to the spatial grid point iy = 10 in the 3D snapshot model with vertical unsigned flux density ⟨ | B_Z | ⟩ = 80 G. Middle panel: height variation of the vertical magnetic field strength B_Z along the same slice. Bottom panel: height variation of the vertical velocity V_Z. Curves show the horizontal fluctuations of the formation height H_Δλ of the Si i 10 827 Å line derived using the Eddington-Barbier approximation. Thick solid curve: Δλ = 0; dotted curve: Δλ = −0.08 Å; dash-dotted curve: Δλ = −0.2 Å. Dashed curve indicates the formation height of the line continuum. Two vertical lines correspond to the grid points ix = 28 (a granule) and ix = 59 (an intergranule).