Ok, let's hear it!

[Aquattro]

KInda lost me at

The light spectrum on the surface can be defined as a function I0(λ), where λ is the wavelength and I0 is the intensity for corresponding wavelength at zero depth. Hence the adsorption spectrum Ia(λ) at the depth D can be determined as
Ia(λ) = I0(λ) · K(λ) · D (1)