Atmospheric window

[4][5] In other fields of science and technology, such as radio astronomy[6] and remote sensing,[7] the term is used as a hypernym, covering the whole electromagnetic spectrum as in the present article.

[8] Out of an average 340 watts per square meter (W/m2) of solar irradiance at the top of the atmosphere, about 200 W/m2 reaches the surface via windows, mostly the optical and infrared.

Also, out of about 340 W/m2 of reflected shortwave (105 W/m2) plus outgoing longwave radiation (235 W/m2), 80-100 W/m2 exits to space through the infrared window depending on cloudiness.

In a complementary manner, the infrared window also transmits to the surface a portion of down-welling thermal radiation that is emitted within colder upper regions of the atmosphere.

Application of the Beer-Lambert Law may yield sufficient quantitative estimates for wavelengths where the atmosphere is optically thin.

Τhe absorption bands of Earth's atmosphere (grey colour) delimit its atmospheric windows (middle panel) and the effect they have on both downgoing solar radiation and upgoing thermal radiation emitted near the surface is shown in the top panel. The individual absorption spectra of major greenhouse gases plus Rayleigh scattering are shown in the lower panel. [ 1 ]