Anti-greenhouse effect
The anti-greenhouse effect is a mechanism similar to the greenhouse effect, but with the opposite consequence of cooling the surface temperature of a planet. If gases in the atmosphere of a planet have a lesser transmittance for inbound radiation (for instance, solar rays in the Solar System) than for outbound radiation (typically thermal radiation of the planet's surface in the infrared domain), the surface temperature at which inbound and outbound heat fluxes are at equilibrium is lower.
On Earth
On Titan
The haze containing organic molecules in Titan's upper atmosphere absorbs 90% of the solar radiation reaching Titan, but is inefficient at trapping infrared radiation generated by the surface. Although a large greenhouse effect does keep Titan at a much higher temperature than the thermal equilibrium, the anti-greenhouse effect due to the haze reduces the surface temperature by 9 K. Because greenhouse effect due to other atmospheric components increase it by 21 K, the net effect is that the real surface temperature of Titan (94 K) is 12 K warmer than the effective temperature 82 K (which would be the surface temperature in the absence of any atmosphere, assuming constant albedo).[1] [2]
References
- C.P. McKay; J.B. Pollack & R. Courtin (6 September 1991). "Titan: Greenhouse and Anti-greenhouse Effects on Titan". Science. 253 (5024): 1118–21. doi:10.1126/science.11538492. PMID 11538492.
See also McKay, ""Titan: Greenhouse and Anti-greenhouse," Astrobiology Magazine November 03, 2005 (retrieved October 3, 2008) - "Titan's Greenhouse Effect and Climate: Lessons from the Earth's Cooler Cousin" (PDF). Retrieved 24 February 2017.