Interrelations of UV-global/global/diffuse solar irradiance components and UV-global attenuation on air pollution episode days in Athens, Greece

摘要

An investigation of global ultraviolet (G_(UV)), global (G) and diffuse (G_d) solar intensities, continuously recorded over a period of five years at a station in Athens, Greece, and stored on the basis of hourly time intervals since 1996, has revealed the following: (a) UV-global irradiation, associated with the 290-395 nm wavelength region, constitutes 4.1/100 of global solar. (b) UV-global irradiance ranges from an average minimum of 2.4 W m~(-2) and 3.1/100 of global solar in January to an average maximum of 45 W m~(-2) and 7.8/100, respectively, in June, both considered at 13:00, solar time. (c) There exists a good correlation among the two dimensionless irradiance ratios G_(UV)/G_d and G_d/G in the form of an exponential relationship.