The influence of horizontal radiative transfer on the accuracy of absorption estimates as differences between the net fluxes measured above and below the clouds is studied. With such an absorption retrieval scheme, the horizontal transfer is interpreted as an apparent absorption and is the major source of uncertainty.
If the measured net fluxes are averaged over intervals ~6 km or longer, the horizontal transfer can be neglected, and reliable estimates of the average (over this interval) absorption can be obtained. Realization (~200 km long) average albedo, transmittance, and absorptance can be obtained, provided the interval between successive net flux measurements is not longer than ~10 km. Simultaneous net flux measurements of the visible and shortwave (0.4-4.0 mm) radiation allow one to substantially improve the absorption estimates and to study the absorption variability at small (~0.1 km) scales.