Solar radiation is absorbed by earth surface e reradiated to space as short or longwave radiation. The flux reaching the surface is balanced by another one in a different way and anything disturbing this balance can affect climate, like aerosols. This work used calculated and observed shortwave radiation in order to evaluate aerosol influence on radiation fluxes. Calculated values of irradiances were obtained by Global Model (Model GL) version 1.2 which uses satellite information (GOES 12) and evaluates global and UV+VIS radiation including water vapor, carbon dioxide and ozone absorption. Original data are reflectance with a spatial resolution of one pixel for 4 km (nadir at 75W longitude) and obtained radiation is reduced to average day radiation. Observed data were measured by pyranometers in different parts of Brazil (INPE network - PCD´s) which have the following sensors: temperature, relative humidity, pluviometer, wind speed, solar radiation (global and PAR), barometer, soil temperature, heat soil flux and total liquid radiation. GL model does not consider atmospheric aerosols in spite of they have an important role in radiation balance. In Amazônia Region and central Brazil biomass burning (mainly in September and October) can generate large amounts of aerosol. Model results were analyzed for five years (2001 to 2005) and compared to experimental data for some specific areas. Generally model results were greater than experimental data. It was observed a seasonal cycle for differences and values around +25 W.m-2 in areas with biomass burning aerosol presence (Cuiabá (56.07W;15.55S), for example). Studying areas without the presence of this aerosol, differences dropped to values smaller than +10 W.m-2. Temporal analysis showed an increase in differences since April, 2003, probably due to no correction in signal satellite degradation.Pages: 669-67
