ATMO 201 Lecture Notes - Lecture 5: Negative Feedback, Positive Feedback, Ideal Gas
1 Feb 2017
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Document Summary
Read appendix b (ideal gas, stefan-b law, and wein"s law) Region where co2 and h2o vapor do not absorb ir radiation (8-11 um: emitted lw energy passes freely into space. When clouds are present they do absorb at these wavelengths. Cirrus clouds tend to trap lw (ir) radiation: high in atmosphere, made of ice crystals. Cumulus clouds reflect sw (uv) radiation: lower in atmosphere, made of water, can also emit ir radiation at cloud top by absorbing heat from surface. Earth is warming - rate of . 6 c per century. H2o and co2 play large roles in the warming: methane, nitrous oxide, and cfcs; stronger warming but much smaller roles (low concentrations) Solar radiatio(cid:374) (cid:272)o(cid:373)es i(cid:374), ghg let i(cid:374) (cid:272)o(cid:373)e i(cid:374) (cid:271)ut does(cid:374)"t let earths radiatio(cid:374) leave. Positive feedback - more warming, more water vapor released into atmosphere, more warming. Negative feedback - more water vapor, more clouds, less warming.
