CHE 310 Lecture 5: CHE310Greenhouse

• School: Stony Brook University
• Department: Chemistry
• Course: CHE 310
• Professor: Katherine Aubrecht

Document Summary

Blackbody = an idealized object that absorbs all incident radiation and reradiates the absorbed energy in a smooth spectrum that is only dependent on temperature. Bodies give off radiation with shorter wavelengths as temperature increases. Earth absorbs radiation mainly in the visible region, but gives off radiation in the ir region. With no atmosphere, rate at which energy is emitted = rate at which energy is absorbed. Rate e(cid:374)erg(cid:455) is e(cid:373)itted (cid:271)(cid:455) earth = (cid:1008) r2kt4. E(cid:373)its radiatio(cid:374) fro(cid:373) its e(cid:374)tire surfa(cid:272)e (cid:894)(cid:1008) r2 = area of sphere. Rate earth a(cid:271)sor(cid:271)s e(cid:374)erg(cid:455) fro(cid:373) the su(cid:374) = r2(1-a)s0. U(cid:374)"s radiatio(cid:374) hits the earth i(cid:374) the shape of a (cid:272)ir(cid:272)le (cid:894) r-2 = area of a circle) S = rate solar radiation is absorbed and reemitted. S0 = flux of solar energy directed at the earth = 1370 w m-2. A = albedo (energy reflected back to space) = 0. 3 for earth k = stefan-boltzmann constant = 5. 67x10-8 w m-2 k-4.