Equatorially averaged (i.e. the zonal-mean at the equator) T–P profiles (orange) for two evolved models that were either isothermally (a) or adiabatically (b) initialised. In both cases there is no forcing below 10 bars (i.e. when P > 10 bar), and the forcing above this point is plotted in dark grey. In both cases, the models have been run long enough such that their T–P profiles have fully evolved from their initial states, either isothermal (a) or adiabatic (b) for P > 10 bar, as shown by the light grey dashed line, to the same steady state, a deep adiabat that corresponds to T_surface = ~1900 K – which is ~100 K hotter than the equilibrium temperature at 10 bar.