Radiant energy transfer in waters

Abstract

A model is presented for predicting the local radiant flux and the net rate of gain or loss of radiant energy per unit volume on spectral and total bases for a layer of natural water by using exact radiative transfer theory. The model considers attenuation (absorption and scattering) and multiple scattering by water and accounts not only for the transmission and internal reflection of radiation at the air‐water interface but also for reflection at the bottom. Some numerical results are reported for pure water, multiple scattering being neglected. The results show that analyses that neglect the spectral nature of the incident flux and assume water to be gray lead to appreciable errors in total radiant flux computations and in the amount of internal absorption of solar radiation. For accurate predictions, the reflection from the bottom and the internal reflection from the air‐water interface must be properly accounted for in shallow waters.