Study: El Niño may give advance warning of extreme heat in the Amazon

Conditions linked to the El Niño phenomenon and the warming of the tropical Atlantic may provide signals of extreme heat in parts of the Amazon up to seven months in advance, according to a new study.

The study, published in the journal Earth’s Future, analysed the influence of the main patterns of natural climate variability on temperatures and rainfall across the Amazon basin.

The researchers found that periods of extreme heat become more likely after exceptionally warm El Niño-related conditions in the tropical Pacific, as well as after warming in parts of the tropical Atlantic.

The strongest signal was identified for the March–May period, when extreme temperatures in the Amazon were linked to ocean temperature changes observed up to seven months earlier.

“It is quite remarkable that heat extremes are connected to conditions in the Pacific Ocean and the tropical Atlantic Ocean observed up to seven months earlier,” said Andrea Taschetto, an associate professor at UNSW and a co-author of the study.

To reach these conclusions, the researchers analysed monthly climate data from 1950 to 2023, covering six regions of the Amazon. They also used machine-learning techniques to study cases in which high temperatures coincide with dry conditions.

The findings could help improve early forecasts of periods of extreme heat and drought in the Amazon, giving authorities and communities more time to prepare for possible climate impacts.