How transparent or opaque are atmospheric clouds at infrared wavelengths?

Question

In other words, if I had an infrared camera or binoculars, would I be able to see through clouds? I refer to water droplet clouds, not dust clouds. Thank you.

Answer 1

You would not see through clouds. Liquid water has strong absorptions at approximately 3400 cm-1 (O-H stretch, very broad), 1640 cm-1 (bending) and 1200 cm-1 and under (librations). About >90% of the infrared radiation is absorbed in 10 microns (1e-5m) at these wavelengths and clouds are more than a few microns thick. As the thickness of water increases, so does the breadth of the absorption lines, so the wavelengths between and near the absorptions mentioned get 'filled in'. Secondly, droplets in clouds are comparable in size to infrared wavelengths, so Mei scattering is important. Even if light is transmitted, all spatial information is lost.