Liz B. C. Belém, Ronaldo Albuquerque, Leonardo Faria Peres, Filippe L.M. Santos, Julia Abrantes Rodrigues, Lucas S. Menezes, Patrícia S. Silva, Ricardo M. Trigo, Carlos C. DaCamara, Ana Russo, João L. Geirinhas, Geraldo A. Damasceno Junior, Fabio Oliveira Roque, Ana M. B. Nunes, Renata Libonati
ABSTRACT The year 2024 was classified by the World Meteorological Organization (WMO) as the hottest on record, both globally and in Brazil. In the Pantanal, exceptional heat waves and intense droughts led to an early onset of the fire season in June, marked by high fire severity and large burned areas. Although the Pantanal has been increasingly affected by combined drought and heat events, the influence of these climatic extremes on fire activity and the associated atmospheric circulation patterns is not well understood. This study assesses the conditions prior to the fire and the simultaneous occurrence of heat waves and droughts based on satellite data and climate indices; 2024 was identified as the most severe drought year over the 1980–2024 period, where virtually the entire biome reached exceptional drought levels. Heat waves were accompanied by significant precipitation and soil moisture deficits, along with the absence of the flood pulse in the rivers, reinforcing the compound nature of the 2024 extreme events. Synoptic conditions revealed patterns favourable to persistent warming and intensified drought, while fire risk indices exceeded the 99th percentile. These results highlight the need for a holistic approach when analysing the climatic factors driving fires, thereby advancing understanding of compound events and supporting public policies aimed at both mitigating and adapting to the impacts of climate extremes in the Pantanal.