A three-dimensional atmospheric radiative transfer model based on the discrete-ordinates method

A three-dimensional, radiative transfer model based on the discrete-ordinates method for application to atmospheric radiation and remote sensing is developed. The model has the capabilities to address one-, two- and three-dimensional rectangular parallelepiped geometries containing nonhomogeneous, absorbing, emitting, anisotropically scattering media. Various boundary conditions including collimated and isotropic radiant sources are incorporated in the model. Where possible, the model takes advantage of symmetric and periodic boundary conditions to reduce the size of the solution domain. The model yields the radiant intensity field as a function of spatial location and direction within the solution domain and for any outward going direction. The model is extensively validated for one-, two- and three-dimensional geometries. The validation is performed through comparison of results from the model against those in the literature. Broken-cloud intensity fields are presented to demonstrate the capabilities of the model.