Comparação da evapotranspiração por duas diferentes análises gradeadas de alta resolução para o Nordeste do Brasil

Abstract

Evapotranspiration (ET) is the second most important variable in the hydrological cycle, second only to precipitation, and influences numerous atmospheric processes. It is therefore important to study changes in this variable in the Brazilian Northeast (NEB), and to assess the accuracy of different data sets that estimate ET for the NEB. A climatological analysis of ET observed between 1961-2020 showed the seasonality of this variable, with its behavior varying in the region according to the periods of greatest atmospheric demand for water from the soil-plant system. When applying a cluster analysis, it was observed that the best division is for six homogeneous ET groups in the NEB. For each of these groups, there were positive trends in ET over the 60 years of observed data analyzed, but with different periods of structural changes in the time series, with three groups presenting it in the 1970s and another three groups in the 1990s. The evaluation of two sets of data that estimate ET, one based on remote sensing, MODGroETa, and the other on reanalysis, ERA5Land, shows that the latter has higher correlations and lower errors compared to the former, especially after a detailed analysis and subsequent correction of the biases observed in the period of analysis, which was from 2000 to 2018 on the decadal time scale.