White colour of clouds is due to which phenomena?

CONCEPT:

Rayleigh's law of scattering:

• According to Rayleigh's law of scattering, the intensity of light of wavelength λ present in the scattered light is inversely proportional to the fourth power of λ, provided the size of the scattering particles are much smaller than λ. Mathematically,

\(I \propto \frac{1}{\lambda }\)

• Thus the scattered intensity is maximum for shorter wavelength.

EXPLANATION:

• Clouds are white because light from the Sun is white.
• As light passes through a cloud, it interacts with the water droplets, which are much bigger than the atmospheric particles that exist in the sky.
• When sunlight reaches an atmospheric particle in the sky, blue light is scattered away more strongly than other colours, giving the impression that the sky is blue.
• But in a cloud, sunlight is scattered by much larger water droplets.
• These scatter all colours almost equally meaning that the sunlight continues to remain white and so make the clouds appear white against the background of the blue sky.
• Light entering the Earth's atmosphere gets scattered by coming in contact with atmospheric particles.
• This phenomenon is called the scattering of light.