Since the atmospheric transmission/parameterized models (i–iv) are not appropriate for all applications, the simple empirical method (v) can usually meet application demands. Given measured broadband solar components, PAR photon flux components can be obtained as a fraction of these broadband solar components. The present analysis contributes to the study of solar radiation in urban Athens environment through the investigation of the temporal variation of measured global and diffuse PAR and their relationships with the respective broadband solar components.