Temperature gradient against temperature of the uppermost layers. The temperature range shown corresponds to the uppermost 0.0034 R_⊙. The thin light blue and light pink lines show the profiles for SSM-MLT and SSM-1KM, respectively. The dashed black line shows the profile of a solar model using an averaged 3D atmosphere as outer boundary condition (“patched model”, Jørgensen & Weiss 2019). The green, purple, turquoise, and orange lines show the profiles for the fully non-local 3KM, and for case A, case B, and case C, respectively (see Table 2).