For some meteorological applications, knowledge of incoming solar radiation at surface level (Sin) is very important. Conventional measurements of this flux by individual sensors are representative of small areas only. On the other hand, meteorological satellites allow a regular cover of the entire globe, providing estimates of radiative fluxes over wide areas, within the spatial resolution of the sensor (a few km). In addition, reanalysis products provide alternative Sin estimates that must be adequately validated. This work compares four long-term Sin databases for South America: three reanalysis products (NCEP/NCAR, ERA-40 e Eta/CPTEC) and the database produced by the algorithm GL1.2, which estimates Sin from a set of GOES images. The results indicate that the monthly fields of the NCEP/NCAR and the ERA-40 and the GOES-based estimates are very similar for all studied regions. On the other hand, Eta/CPTEC reanalysis presents much higher radiation values, for both the long-term annual and monthly means over South America.
Solar Radiation Incident; Reanalysis; datasets
