Climatic Characterization of Heat Waves in Brazil

According to the state-of-the-art global and circulation models the probability of occurrence of large heat waves in the following decades will increase significantly. Currently, due to their significant impacts in several socio-economic areas such as public health, energy production and consumption and agriculture, there are numerous studies for the Northern Hemisphere regions evaluating this problem. However, for the southern hemisphere and especially Brazil, a similar analysis is lacking, despite its huge geographical area and large population potentially affected. The main goal of this work is to provide a comprehensive diagnostic study of heat waves observed in several large Brazilian cities, including heat waves frequency, seasonal distribution and temporal evolution since the 1960s decade. In general, results indicate the presence of a positive trend in the frequency and duration of heat waves since the 1980s, with special emphasis to cities like Sao Paulo, Manaus and Recife. Brasilia was the city that in the last decades recorded the highest number of heat waves while Rio de Janeiro was the city with the smallest number recorded. In respect to seasonal variability the Autumn/Winter months were the months with the largest number of heat waves recorded.