Spatiotemporal analysis of meteorological variables in the Brazilian semiarid region: A multiscale approach

Solar and wind energy are important renewable sources in the global energy mix and play a key role in the energy transition and in meeting international climate targets. The Brazilian semiarid region is a strategic area because of its abundant wind and solar resources and its high potential for sustainable energy generation. This study provides an integrated analysis of spatial trends, temporal dependence, and the complexity of mean wind-speed and mean global solar-radiation series in 27 municipalities in the Brazilian semiarid region. ERA5-Land reanalysis data for 1981–2024 were used for the regional trend analysis, whereas observational data from the Brazilian National Institute of Meteorology (INMET) for 2009–2024 supported local analyses of autocorrelation, entropy, and cross-correlation across multiple time scales. The results indicated statistically significant positive trends for both variables, with greater spatial homogeneity for solar radiation and greater heterogeneity for wind speed. The series exhibited long-range persistence, with α D F A exponents close to or greater than 1 in some municipalities, indicating temporal memory. The entropy measures revealed scale-dependent behavior: greater regularity was observed at short scales ( n < 30 days); irregularity progressively increased at intermediate scales ( 30 < n < 250 days); and entropy values approached saturation at larger scales ( n > 250 days). The cross-correlation analysis, estimated using the ρ D C C A coefficient, revealed a predominance of positive associations between wind speed and solar radiation, which intensified at larger time scales. The integration of 44 years of regional screening with local multiscale diagnoses based on 16 years of observations enabled the joint characterization of spatial trends, long-range persistence, temporal complexity, and cross-correlation between wind and solar resources. The results broaden the understanding of the spatiotemporal variability of these resources in the Brazilian semiarid region and provide support for regional climate studies and renewable-energy system planning.