Scripps Institution of Oceanography

U.S. Bureau of Ships Report No. 3-5.  Recent experimental determinations of the up and downwelling irradiances in Lake Pend Oreille are studied with the purpose of explaining certain observed nonlinear trends in the semilog plots of these irradiances at shallow depths. A mathematical model which describes these irradiances is derived from the basic equations of radiative transfer. The model explains the observed phenomena in terms of the inherent optical properties of the medium and its external lighting conditions, and we arrive at a fairly detailed understanding of the light field at extreme depths (shallow and deep) in all homogeneous natural hydrosols.