Observations and inversion results. Top panels: Maps of the observed intensity at three different wavelengths (from left to right): continuum of the Fe I line at 630 nm, core of the Mg I line at 517 nm, and core of the Ca II line at 854 nm. Middle panels: Temperature inferred from the inversion at three different optical depth levels (from left to right): τ_c = 1 (photospheric continuum), τ_c = 10^−2.5 (high photosphere), and τ_c = 10⁻⁵ (chromosphere). Bottom panels: Same as middle panels but showing the inferred line-of-sight velocity. Inner and outer blue circles are located at radii r/R_s = 0.4, 1.0, 1.4, respectively, where R_s is defined as the sunspot’s radius as measured from the umbral center (red cross). The direction of the solar disk center is indicated by the bold arrow. Dashed black lines depict a cone of ±15° around the line of symmetry of the spot.