Avaliação da variabilidade climática no verão sobre a região nordeste do Brasil simuladas pelo Modelo Global BAM

Abstract

The Brazilian Northeast (NEB) suffers from the irregular distribution of rainfall throughout its territory. This variability is linked to the various meteorological systems responsible for the mechanisms that regulate rain and air temperature, as well as causing major socioeconomic problems for the population. Thus, the objective of the present study is to evaluate the performance of the model (BAM - Brasilian atmospheric Model) to simulate the variability of the regional climate in the NEB and the associated atmospheric circulation characteristics during the southern summers of 2011 (La Niña), 2014 (Normal) and 2016 (El Niño). The simulations of the BAM model were obtained from the Weather Forecast and Climate Studies Center / National Institute for Space Research (CPTEC / INPE). The analyzes show that BAM was able to simulate the patterns of atmospheric circulation and air temperature in the low and high levels of the atmosphere over the NEB and the interannual variability during the aforementioned summers, when compared to the reanalysis of ERA5 and MERRA2, as well as for precipitation, however compared to the GPCP analyzes. The best skills were observed for the air temperature field in all areas investigated, relative to the precipitation field, during the three southern summers. However, over the region comprised by a large part of Bahia and portions south of Piauí and east of Tocantins (NE2 region), both the precipitation variable and the air temperature showed the highest BIAS and RMSE values.