| Popis: |
The Climate of the Northeast Region of Brazil (NEB) has been intensively studied and analyzed. Studies have used objective climate classification methods such as the aridity index of the United Nations Environment Programme (UNEP) (AIUNEP), however, without fully satisfactory results. The input variables needed for calculation of the AIUNEP are precipitation and reference potential evapotranspiration (ET0). However, although rainfall stations that record routine measurements of precipitation data are well distributed in the NEB, weather stations that provide the set of variables necessary for the estimation of ET0 are scarce. When weather stations are absent in a location, ET0 is interpolated, but this can lead to errors. Another objective climate classification approach is the Thornthwaite method, which is based on the determination of the moisture index (Im), whose calculation also requires weather stations data. Therefore, seeking improve the spatial distribution of information on meteorological variables in the NEB, the present work had as one of the objectives to validate reanalysis data from ERA5 of the European Center for Medium-range Weather Forecast (ECMWF) and the unified gauge-based analysis of global daily precipitation project of the Climate Prediction Center/National Oceanic and Atmospheric Administration (CPC/NOAA). After validation, climatic classifications were developed for the NEB using the AIUNEP and Im indices. It was observed that Thornthwaite climate classification tended to overestimate the aridity of the NEB, while the classification using AIUNEP tended to underestimate it. For these reasons, a new climate classification index, called absolute aridity index (Iab), yielding satisfactory results. |
