Interannual variability of solar irradiance over the Amazon Basin including the 1982-83 El Nino Year

Surface solar irradiance was derived over the extended Amazon Basin using AVHRR observations from polar-orbiting satellites during four July months (1983-1986). Observations from the geostationary satellite GOES for July 1983 were also used to assess diurnal effects. Both satellite datasets are part of the Satellite Cloud Climatology Project (ISCCP) B3 product. It was demonstrated that it is now possible to derive long-term surface solar irradiance, which can be useful in climate studies, and that the accuracy of the derived fields is sufficient to detect interannual differences that can exceed at times 70 W/sq m.