Consider the following simple model to describe solar radiation incident on the earth, in which the atmosphere is included. a fraction f of the incident solar flux is absorbed 12 by the atmosphere and a fraction a is reflected, the rest being absorbed by the earth. assume that the only heat transfer to the atmosphere from the earth is by radiation and that f-0.25 and 0.3. find the temperature t, of the surface of the earth for radia tive equilibrium.