Radiation Balance Estimates Over Southeastern Brazil: Ground Observations, Satellite and Reanalysis

Abstract

Due to the high economic activity and population density, the southeast region of Brazil experiences accelerated pro-cesses of changes in land use and cover, which contribute to modifications in the radiation balance (RB) at the surface. In this study, we evaluated the RB components from different state-of-the-art high resolutions datasets over this region of the country during two periods (Feb/2005-Jan/2006 and Mar/2015-Feb/2016). In general, all datasets adequately represented the seasonality of the RB components (except albedo). The ERA5-Land has the lowest mean relative error to represent albedo (≈ 15%), downwelling longwave radiation (DLWR ≈ 4.5%) and upwelling longwave radiation (ULWR ≈ 3.6%). In the case of the downwelling shortwave radiation estimation, GLASS was the best (≈ 14%). Uncertainties in the latter may be associated with the difficulty in representing the variability of cloud cover during the rainy season. Failures in estimating albedo are due to the inability to simulate surface properties. DLWR and ULWR presented the best performances and their uncertainties were related to problems in the computation of air and surface tempera-tures, respectively. ERA5-Land and GLASS are adequate to estimate RB components in southeastern Brazil.