Consider the global energy balance that might occur after a nuclear war. The res
ID: 283929 • Letter: C
Question
Consider the global energy balance that might occur after a nuclear war. The resulting smoke and dust in the atmosphere absorb 75% of the incoming sunlight (257 W/m^2), while the albedo is reduced to nearly 20%. Convective and evaporative heating of the atmosphere from the Earth's surface is negligible, as is the energy reflected from the Earth's surface. The Earth's surface radiates 240 W/m^2, all of which is absorbed by the atmosphere. Assuming that the Earth can be modeled as a blackbody emitter as shown in the figure below, find the following (equilibrium) quantities: The "nuclear winter" temperature of the surface of the Earth X, the rate at which radiation is emitted from the atmosphere to space Y, the rate of absorption of short-wavelength solar radiation at the Earth's surface Z, the rate at which the atmosphere radiates energy to the Earth's surfaceExplanation / Answer
answer- when a nuclear war is happen the the large amount of dust and smoke occur in the atmosphere. it comes in atmosphere and affect the heat buddget of the atmosphere. It dont enter the incoming short wave solar radiation and and dont not escape out the long wave outgoing radiation.
In current scenario this dust and smoke have absorb 75%
so amount of incoming solar radiation that is being absorbed is 257 W/m2.
and reduced the albedo nearly 20%. and earth surface radiates 240 W/m2.
nuclear winter temperature is hypothsized temperature of nuclear war. nulcear war has reduced the incoming solar radiation because of nuclear war the surface temperature remained 2-6 degree less than normal temperature so the nuclear temperature during nuclear war is varied between 20-40 degree celcius.
answer- the amount of solar radiation that is being sent to space = 69W/m2
the rate at which earth atmosphere emit energy outside (X) is = total emit radiation /total radiation 69 /342 = 0.20 W/m2
the amount of radiation that is sent to earth surface is (z) = total radiation - (emited radiation from atmosphere+ absorbed radiation) = 342- (69+257) = 16 W/m2
the amount of short wavelength that is been absorbed at the earth surface = 16W/m2. because earth surface is considered as blackbody emitter who absorb all incoming radiation. so amount absorbed is 16W/m2