Temperature at 7.392 Mm above bottom boundary of model, corresponding approximately to log τ₅₀₀ = 0 in the quiet Sun, where τ₅₀₀ is the continuum optical depth at λ = 500 nm. The red rectangle delimits the region of interest for the forward synthesis shown in Fig. 2.

Fig. 2.

Panel (a): Normalized peak intensity of Mg I 12.32 μm line calculated by RH 1.5D for MURaM model. Panel (b): Sunspot umbra. Panel (c): Quiet Sun. The blue crosses in panels b and c mark the pixels used for the analysis in Section 3. Note that the white sprinkles indicate points where the radiative transfer calculation fails to converge or crashes.