Ultraviolet climatology over Argentina
Author(s)
Eduardo Luccini
Alexander Cede
Rubén D. Piacentini
Pablo O. Canziani
Date Issued
13 de septiembre de 2006
Type
Article
Volume
111
Issue
D17
Abstract
Satellite‐derived climatologies of UV index (UVI) and erythemal daily dose were determined for Argentina at a geographical resolution of 0.5° latitude by 0.5° longitude. Total Ozone Mapping Spectrometer climatology of key input parameters was used to calculate the clear‐sky ground‐level solar UV irradiance. NASA Surface meteorology and Solar Energy cloud cover data were used to determine the UV attenuation by clouds. Two cases were tested: (1) monthly averages of total cloud cover and (2) monthly averages for three ranges of cloud cover percentage (0–10%, 10–70%, and 70–100%). Case 2, with smaller biases, was selected. Measured erythemal irradiance at seven stations of the Argentine Ultraviolet Monitoring Network was used to validate the satellite‐derived climatologies, as well as to estimate aerosol parameters, surface albedo corrections, and UV cloud transmittance for the calculations. Annual average biases of the monthly mean satellite‐derived UVI and erythemal daily dose with respect to the ground measurements are mostly within ±10%. The strong longitudinal gradient of UV levels toward the Andes Mountains is emphasized. Very high UVI and erythemal daily dose values are registered in the northwestern tropical high‐elevation Andean plateau, with extreme monthly means above 18 and 10 kJ/m 2 respectively, in December–January. Even northern low‐elevation regions show averages over 12 and 7 kJ/m 2 , respectively. On average, clouds attenuate the clear‐sky erythemal irradiance by less than 20% for most of the continental region during all months. UV levels are considerably higher than those for equivalent regions in the Northern Hemisphere.
Subjects