SCI1300 Lecture Notes - Lecture 4: Outgoing Longwave Radiation, The Green House, Inverse-Square Law

• School: Monash University
• Department: Science
• Course: SCI1300
• Professor: Christian Jakob

Document Summary

Sci1300 lecture 4 from science to society. The green house effect and the global energy balance. Retur(cid:374)i(cid:374)g to our (cid:448)er(cid:455) si(cid:373)plisti(cid:272) (cid:373)odel of the earth"s radiati(cid:448)e (cid:271)ala(cid:374)(cid:272)e, (cid:449)e (cid:373)ust (cid:271)ala(cid:374)(cid:272)e incoming radiation with outgoing radiation. (the incoming shortwave radiation must balance the outgoing longwave radiation. ) Energy input -> climate change -> energy output. The average (cid:448)alue of this u(cid:454) is (cid:272)alled the solar (cid:272)o(cid:374)sta(cid:374)t, (cid:1004), a(cid:374)d has a (cid:448)alue of roughl(cid:455) (cid:1005)(cid:1007)7(cid:1004) Remember from daisyworld that the fraction of radiatio(cid:374) re e(cid:272)ted is deter(cid:373)i(cid:374)ed (cid:271)(cid:455) the al(cid:271)edo, (cid:449)hi(cid:272)h depe(cid:374)ds o(cid:374) the surfa(cid:272)e. To (cid:272)al(cid:272)ulate the total e(cid:374)erg(cid:455) a(cid:271)sor(cid:271)ed (cid:449)e (cid:374)eed to (cid:373)ultipl(cid:455) the u(cid:454) (cid:449)ith the area that intercepts that radiation. As we can see, that area is a disk with the radius of the. Energy emitted by the earth: how much energy is emitted per unit area from the earth, for a good estimate of this number, we can assume that the earth is a blackbody.