Question

What kind of scattering (Rayleigh, Mie, or non-selective) would you expect to be most important when radiation of the specified wavelength encounters the following natural or anthropogenic particles?

Slides 16-31, Lecture 2 ought to help - slides 19, 24, and 31 are key.
Wavelength O2 molecules Smoke particles Cloud droplets Rain droplets
(size 10^-10 m) (size 0.3 (μm) (20 μm) (size 3 mm)
550 nm
11 μm
1600 nm
1 cm

Answer 1

1. Rayleigh scattering takes place when the particle size is smaller than the wavelength (λ).

2. Mie scattering takes place when particle size is nearly equal to the wavelength (λ).

3. Non-selective scatter takes place when particle size in greater than the wavelength (λ).

We have the sizes of different particles :

`$O_2 \rightarrow 10^(10) \ m $`

Smoke particles
`$\rightarrow 3 * 10^(-7) \ m$`

Cloud droplets
`$\rightarrow 2 * 10^(-5) \ m$`

Rain droplets
`$\rightarrow 3 * 10^(-3) \ m$`

Wavelength
`$ O_2 $` Smoke particles Cloud droplets Rain droplets

`$10^(-10) \ m$`
`$ 3 * 10^(-7) \ m$`
`$ 2 * 10^(-5) \ m$`
`$ 3 * 10^(-3) \ m$`

`$5500 * 10^(-4) \ m$` Rayleigh Non-selective Non-selective Non-selective

`$11 * 10^(-6) \ m $` Rayleigh Rayleigh Non-selective Non-selective

`$1600 * 10^(-10) \ m $` Rayleigh Non-selective Non-selective Non-selective

`$10^(-2) \ m $` Rayleigh Rayleigh Rayleigh Mie