Incoming and outgoing long-wave radiation, Brunt's formula

Incoming long wave radiation as a function of air temperature estimated with Brunt's formula, compared with the outgoing long wave radiation calculated with surface temperature set equal to the air temperature, for four different meteorological situations:

Blue = overcast sky; h=100%.                   Green = overcast sky; h = 60%.

Turquoise = clear sky; h = 100%.              Red = clear sky; h = 60%.

Violet = outgoing radiation.