Why are Clouds White?
Why are clouds white an not other colors?
In fact, clouds are other colors, which gives you a strong clue as
to why they are white. For example, when you look towards a sunrise
or sunset, if there are clouds present, they take on the yellow /
orange / red hue of the sunset. The water particles are scattering
all the light that hits them. If they only have long wavelength
light hitting them (as at sunrise or sunset) they appear red. But
in the daytime the full sun hits them. As a result they scatter all
colors of light and they appear white.
Clouds are white when they reflect the sun's light. The different
particle sizes of water droplets in the clouds reflect all colors
which, to our eyes looks white. But not all clouds look white. If
the cloud is between us and the sun, the water soaks up (absorbs)
the sun light and then, depending on how thick the clouds are, they
can look gray or even black.
Hope this helps.
R. W. "Bob" Avakian
B.S. Earth Sciences; M.S. Geophysics
Oklahoma State Univ. Inst. of Technology
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Update: June 2012