Main atmospheric input parameters of the model sub-domain used in this work at heights z = 0 km (i.e. at the height of average τ_c = 1; panels on the right) and z = 240 km (the approximate line core formation region of the investigated lines; panels on the left). Plotted, from top to bottom, are the vertical component of the magnetic field, B_z, the hydrogen number density, n_H, the vertical component of the velocity, v_z, and the temperature, T.