Anti-Greenhouse Effect

From Wikipedia, the free encyclopedia

The Anti-Greenhouse Effect is a neologism used to describe two different effects, coming under the header of "the cooling effect an atmosphere has on the ambient temperature of the planet". Unlike the greenhouse effect, which is common, an anti-greenhouse effect only exists in two known situations.

[edit] Titan

The conventional greenhouse occurs because the atmosphere is largely transparent to solar radiation, but largely opaque to infrared. In an anti-greenhouse effect, this situation is reversed (i.e. the atmosphere is opaque to solar, but lets out infrared). The haze containing organic molecules in Titan's upper atmosphere reflects infrared radiation and cools the moon by approximately 10 kelvins[1] and is the only known example of this effect. This is a similar effect to a nuclear winter.

[edit] Pluto

A somewhat different mechanism exists on Pluto. Sunlight striking the nitrogen ice on the surface of dwarf planet Pluto causes it to sublimate; this causes the temperature of Pluto to be about 10 kelvins lower than its moon Charon [2]. The sublimation causes cooling, and is analogous to solar radiation evaporating water on the earth; however when this occurs on earth it is not called an anti-greenhouse effect.

This effect was discovered using the Submillimeter Array in Hawaii.