| Abstrakt: |
There has been a large effort to relate the apparent optical properties of ocean water to the inherent optical properties, which are the absorption coefficient a, the scattering coefficient b, and the scattering phase function ρ(θ). The diffuse attenuation coefficient k_diff has most often been considered an apparent optical property. However, k_diff can be considered a quasi-inherent property k_diff′ when defined as a steady-state light distribution attenuation coefficient. The Honey–Wilson research empirically relates k_diff to a and b. The Honey–Wilson relation most likely applies to a limited range of water types because it does not include dependence on ρ(θ). A series of Monte Carlo simulations were initiated to calculate k_diff′ in an unstratified water column. The calculations, which reflected open ocean water types, used ranges of the single-scattering albedo ω_0 and the mean forward-scattering angle θ_m for two analytic phase functions with different shapes. It was found that k_diff′ is nearly independent of the shape of ρ(θ) and can be easily parameterized in terms of a, b, and θ_m for 0.11 ≤ θ_m ≤ 0.48 rad and 0.5 ≤ ω_0 ≤ 0.95. k_diff′ is an asymptotic quantity; that is, a steady-state distribution is reached only after many scattering lengths. |
