Vertical profiles of radiative fluxes (I), power per unit volume (J), and power per unit mass (J) for various values of the dimensionless optical depth τ_λ (Eq. (187)). As usual, the reduced altitude, x = z/H, is on the vertical axis. Left: incident flux, defined by Eq. (186), at ψ = 0. If τ_λ ≪ 1 the ground receives almost 100% of the total power. On the contrary, if τ_λ ≫ 1, all the power is absorbed by the atmosphere. Right: radiative flux emitted by the ground, defined by Eq. (206). For small τ_λ, the flux goes through the atmosphere without being absorbed. For high values of the parameter, it is absorbed by the lowest layers.