Simplified spectral radiative transfer model for clear sky conditions in Portugal: application on ultraviolet irradiance computation

A simplified spectral model for retrieval of direct, diffuse and global ultraviolet spectral irradiances on clear sky conditions in Portugal is presented. The model consists on a simplification of the exact codes used on conventional radiative transfer models, assuming a single homogeneous layer and applying the Beer's law formalism, based on models of the same type developed by other authors. The model allows the use of average values of total ozone, aerosol optical depth and precipitate water content according to the available climatological data. Ultraviolet effective irradiances were computed in order to study its geographical variation in Portugal mainland due to altitude and latitude changes (author)