COMPARATIVE STUDY OF UVB AND TOTAL RADIATION ATTENUATION OBSERVED IN A SOUTH AMERICAN REGION

摘要

Some cases showing the relationship between UVB and total solar radiation under cloudless, cloudy and forest fires conditions are presented. The analysis is focused on data collected since 1996 in Asuncion City (Paraguay--25.33S, 57.52W; altitude 130m) during wet (with low aerosol loading and cloudy days) and dry seasons (with biomass burning aerosol predominance in clear-sky days). For the wet season--February/April--a clustering method applied to GOES-8 imagery allowed the identification of different types of clouds. Aerosol content during the dry season--August/September--was assessed using TOMS Aerosol Index. Results suggest a functional relationship between UVB and total irradiances under clear-sky and overcast local conditions. Under fair weather cumulus presence the comparison requires further analysis.