Variabilidade espacial da precipitação pluvial e temperatura do ar em Minas Gerais associada a eventos de El niño

Abstract

The El Niño phenomenon in the equatorial Pacific is characterized by changes in sea surface temperature (SST), atmospheric pressure, winds and tropical convection, directly impacting Brazil's climate dynamics. So, the objective of this monograph is to analyze the relationship between El Niño events and the spatial variability of rainfall and air temperature in Minas Gerais, from 1980 to 2013. For this purpose, rainfall and temperature (minimum and maximum) data were used of the database of Xavier et al. (2017), the TSM for the Niño regions (1 + 2, 3, 3.4 and 4; CPC/NOAA) and their intensities (weak, moderate and strong). El Niño events were identified using the CPCP/NOAA methodology. El Niño events in the Niño 1 + 2 (moderate intensity), Niño 3 (strong intensity), Niño 3.4 (weak and moderate intensity) and Niño 4 (weak and moderate intensity) regions are associated with the predominance of drier trimester in Minas Gerais, while El Niño events in the Niño 1 + 2 region (strong intensity) and Niño 3 (moderate and strong intensity) are associated with the predominance of wetter trimester. El Niño events in the midwest equatorial Pacific are associated with the onset of late rainy season or drier conditions in Minas Gerais, while El Niño events in the eastern equatorial Pacific are associated with opposite conditions. Regarding the minimum and maximum temperature, positive anomalies dominate in the trimester in virtually all El Niño events in the different Niño regions and intensities. El Niño events act as intensifiers of extreme changes in rainfall and air temperature in Brazil, which demonstrates the importance of understanding these relationships in order to provide input for increasingly assertive climate forecasts, especially to prevent and/or minimize the effects of potential social, economic and environmental impacts.