Why Clouds are White--Part 1.5
Still searching for an answer up here. |
There are many explanations out there just as there are explanations for why the sky is blue. I nod at the answer to this one ("because air scatters blue wavelengths of light more efficiently than the other wavelengths in the visible spectrum"), but guess what? I don't really know what that means.
Because I want to know what it means, I am now way down inside the water molecules that make up the clouds, inside the atoms of hydrogen and oxygen, riding the waves of the electromagnetic spectrum, to try to understand what happens to the electrons (if anything) when they are struck by sunlight.
This is getting me close to an answer, which is why this is Part 1.5. I am not quite there yet. Here is what I know: The reason clouds are white has to do with the relative sizes of the cloud droplet and the wavelengths of visible light. Which are both very very incredibly very tiny to us. To a cloud droplet and a wavelength, however, size does matter, though telling you that a cloud droplet is so large that is scatters all wavelengths equally (which is what I am being told) doesn't really explain the phenomenon of white clouds.
So you are confident that The Accidental Naturalist is working diligently on the uber-story of the whiteness of clouds, I am reading a 1970 article from the Journal of Atmospheric Sciences (Volume 27) entitled "On the Possible Absorption of Visible Light by Clouds," by S. Twomy. It was the first article that showed up when I asked Google Almighty this question: Are individual wavelengths of visible light absorbed and emitted within the molecules of water within a cloud droplet or are they scattered without ever penetrating the droplet?
Yes, 1970. That means I have some 41 years of articles to read to bring you the latest science on this very basic and possibly unanswerable question.
Here is a loaf of bread I made on Sunday. It was delicious. When I get lost in the atmosphere, I like to come back down to earth in the kitchen. |