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A Question Regarding Atmospheric Transparency Windows

-- Dave | May 28, 2020

Question:

atmospheric windows
The following website link describes more than one atmospheric window.
Curious of the source if it is different than NRAO.
Also, can the earth radiate electromagnetic radiation through all of these windows? It is known that 8-13um emission can result in passive radiative cooling — can cooling or other effects occur through the other windows?

https://www.gb.nrao.edu/GBTopsdocs/primer/basics_of_radio_astronomy.htm

-- Dave

Answer:

The link you provided appears to no longer be active. A more general discussion regarding astronomical observations from ground-based facilities and how those facilities must content with the absorptive and emissive effects of the Earth’s atmosphere can be found on the “Introduction to Radio Astronomy” page within the Essential Radio Astronomy textbook. I believe that any net cooling of the Earth through an atmospheric window is dependent upon the radiative balance at those frequencies. If indeed one gets cooling of the Earth’s surface at wavelengths between 8 and 13 micron, then it would seem to be the case that the flux of emission coming from outside the Earth’s atmosphere is much smaller than the flux of radiation emitted by the Earth’s surface.

-- Jeff Mangum

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