Effects of meteorology on the annual and interannual cycle of the UV-B and total radiation in Córdoba City, Argentina

Abstract

The Ultraviolet B (UV-B, 280–315 nm) and total (300–3000 nm) irradiances in a suburban site in Córdoba city (31.44°S; 64.19°W) were measured and calculated between November 1998 and December 2002. Measurements were carried out with a pyranometer YES UVB-1 (UV-B) and a pyranometer YES TSP-700 (total) while UV-B calculations were performed by using the radiative transfer model TUV 4.1 (Tropospheric Ultraviolet Visible). The evolution and characteristics of total ozone column values over Córdoba during the last 12 years was analyzed. The stratospheric ozone depletion over Antarctica during the springtime does not affect the UV-B measurements. The agreement between UV-B measurements and calculations for clear sky days at solar noon is better than 10% for zenith angles <70°. A simple model to calculate total radiation was obtained by fitting the experimental values under clear sky conditions. The agreement is better than 5% for zenith angles <70°. The small interannual variability in the total radiation, allows us to use a set of parameters for one year to calculate the annual cycle for any other year. Daily, seasonal, and interannual variations of UV-B and total radiation were characterized for this period. The effect of the total ozone column variability on UV-B annual cycle was analyzed by using the UV-B values in a fixed solar zenith angle interval (55–60°). The role of clouds on the UV-B and total annual cycle is also examined.