Characterization and Spatial Coverage of Heat Waves in Subtropical Brazil

Abstract

Given the increase in the frequency, intensity, and persistence of heat waves since the 1970s, and in view of the impacts that extreme temperatures may cause for society and the economy, this study aims to characterize heat waves in the subtropical region of Brazil and compare findings with the criterion defined by the World Meteorological Organization (WMO). Daily maximum temperature data was used. By using the percentile methodology, the subtropical region was divided into two regions: region 1 and region 2. We identified 54 heat waves in region 1 and 34 in region 2, which occurred more frequently in winter and spring, and less frequently in summer. A close relationship was observed between the Pacific Decadal Oscillation (PDO) and El Niño–Southern Oscillation (ENSO), both of which are able to modulate the heat waves in each of the different regions. Region 1 presented the highest number of heat waves during the warm (cold) phase of the PDO. As for ENSO, heat waves were more frequent in the neutral phase in both regions. Finally, there was shown to be an increase in the frequency and persistence of heat waves since the 1980s, especially in region 2. The methodology used in this study allows the identification and characterization of heat waves in several regions of different climates.

The heat wave of October 2020 in central South America

“…They also note that the statistics of those events are modulated by the Pacific Decadal Oscillation and the El Niño-Southern Oscillation. Climatologies of heat waves based on maximum temperature values and percentiles for Brazil are documented by Bitencourt et al (2016), Geirinhas et al (2017), Simões dos Reis et al (2019), andZhao et al (2019). Geirinhas et al (2017Geirinhas et al ( , 2019 reveal the existence of positive and significant trends in heat wave frequency and duration since the 1980s, particularly for the cities of São Paulo, Manaus and Recife.…”

“…Simões dos Reis et al . (2019) show that heat wave events in Brazil subtropics have become more frequent and persistent since 1979. They also note that the statistics of those events are modulated by the Pacific Decadal Oscillation and the El Niño–Southern Oscillation.…”

Drought–heatwave nexus in Brazil and related impacts on health and fires: A comprehensive review

“…Compared to drought events, relatively few studies in Brazil have focused on HW modeling and interpretation, with the majority of these published since 2011 116–122 . By contrast, most of the HW‐related studies in Brazil mainly focus on public health impacts 21,119,123–133 .…”

“…115 Compared to drought events, relatively few studies in Brazil have focused on HW modeling and interpretation, with the majority of these published since 2011. [116][117][118][119][120][121][122] By contrast, most of the HW-related studies in Brazil mainly focus on public health impacts. 21,119,[123][124][125][126][127][128][129][130][131][132][133] Besides health-related studies in the country, a few studies show HW impacts on agriculture, 134 food production, 135 and fires.…”

Weather and Climate Extremes: Current Developments

“…Rosso et al [17] evaluate the role of the Antarctic Oscillation for precipitation associated with the South Atlantic Convergence Zone, the main summer-typical atmospheric phenomenon occurring in South America. Cordero Simões dos Reis et al [18] show that heatwave events in Brazil subtropics have become more frequent and persistent since 1979 and also note that the statistics of those events are modulated by the Pacific Decadal Oscillation and El Niño-Southern Oscillation.…”