Assume a planet with a one-layer atmosphere has a solar constant S = 2,000 W/m² and an albedo α = 0:4.

(a) What is the planet’s surface temperature? Make the standard assumption that the atmosphere is transparent to visible photons but opaque to infrared photons.

(b) During a war on this planet, a large number of nuclear weapons are exploded, which kicks enormous amounts of dust and smoke into the atmosphere. The net result is that the atmosphere now absorbs visible radiation – so solar energy is now absorbed in the atmosphere. It also still absorbs infrared radiation. Draw a diagram like Figure 4.5 to show the fluxes for this new situation, and calculate the planet’s surface temperature. The solar constant and albedo remain unchanged.

(c) Explain in words why the temperature changes the way it does after the nuclear war. Is describing this as “nuclear winter” appropriate?

Figure 4.5

Transcribed Image Text:

Sun 238 476 12 atmosphere 238 238