Satellite records have detected that, since the beginning of the year, the combination of a strong El Niño episode and a positive temperature anomaly in the Atlantic tropical creates a predictive index that appears up to seven months before the most intense heat peaks in the Amazon. This advance, never observed at this scale, offers decision-makers and local communities valuable time to prepare their responses to temperatures that can exceed usual thresholds for several consecutive weeks.
What the study reveals: Early signals and intensity of Amazonian heat waves
Researchers from the ARC Center of Excellence for the Weather of the 21st Century and the National Institute for Space Research (INPE) in Brazil have studied how large-scale natural climate variability modes influence temperature and precipitation extremes across the Amazon basin. They found that when the El Niño anomaly coincides with an increase in sea surface temperature in the Atlantic tropical, maximum temperatures in the Amazon basin significantly increase compared to the climatological average. Extreme heat episodes – defined as days where the maximum temperature exceeds usual values for several consecutive days – occur on average several months after the El Niño peak, thus providing a new forecasting horizon.
These correlations were confirmed by the analysis of satellite data series and climate models. The study highlights that prediction uncertainty decreases when combining both climate indicators, which represents a substantial improvement over predictions based solely on El Niño.