Investigation of the maximum and minimum temperatures in the semi-arid region of northeastern Brazil

Abstract

Temperature records all over the world provide evidence that the earth’s climate is changing. To investigate changes in the extreme temperatures of semi-arid regions, we analyzed 33 years (1975-2008) of monthly maximum and minimum air temperatures for three weather stations located in Quixeramobim, Crateús and Barbalha Cities, Ceará, Brazil. The data sets were provided by INMET (Instituto Nacional de Meteorologia), Brazil. Dataset of each station was shared in decades to better understand the temperature tendency as well as to identify the warmest one. The two most recent decades were the warmest at all three stations investigated, and the highest temperature values were observed for Barbalha station. The highest increases of maximum temperature occurred during the dry season (May/Dec), and the warmest month was October, during which temperature increases of up to 1.63 °C were observed in the 1980s. The minimum temperature increased substantially during the rainy season (Jan/Apr) and during the coldest months (Jun/Jul). The highest increase of minimum temperature (3.08°C) was observed in July at the Barbalha station. The Quixeramobim station showed no significant increases in minimum temperature. The results indicate that temperature increases occur in an irregular pattern, suggesting that various regional agents affect changes in temperature.