Seasonal Study on Changing Trends in Climatic Extremes Indicators in the Brazilian Territory

Abstract

This study focuses on analyzing trends in extreme climate indices in 11 different regions of Brazil on a quarterly basis, from 1961 to 2019. The aim is to identify changes in climate trends over time, particularly in terms of increasing climatic extremes, such as maximum and minimum temperature. Statistical tests were used to determine the presence of trends and the value of the changes. This study reveals that in most cities exhibited the minimum temperature recorded tends to increase in at least two quarters per year, while only a few did not show significantly increasing trends in maximum temperature. In terms of extreme temperature indices, a few regions presented statistically significant trends, such as Belém and Cuiabá, which showed a reduction in the occurrence of cold nights and hot days, respectively, across all quarters. Significant increases in the percentage of hot days and hot nights, as well as in maximum, minimum, and average temperatures across different regions, were observed. Additionally, in some seasons of the year precipitation events changed, with an increase in the concentration of rain in short periods and in the number of consecutive days without precipitation.