El Nino could predict Amazon heat waves months in advance

A new study published in Earth’s Future reveals that El Nino and warming in the tropical Atlantic could serve as early warning signs for extreme heat in the Amazon, potentially up to seven months in advance. The research, conducted by the ARC Centre of Excellence for Climate Extremes in Australia, analyzed climate data from 1950 to 2023 to understand how natural climate variability affects temperature and rainfall in the Amazon Basin.

The study found that extreme heat in the Amazon is more likely following unusually warm conditions linked to El Nino in the tropical Pacific and warming in parts of the tropical Atlantic. The strongest predictive signal was identified for the March-May period, where extreme heat in the Amazon could be linked to ocean conditions observed up to seven months earlier.

It is quite surprising that heat extremes are linked to conditions in the Pacific and tropical Atlantic Oceans observed up to seven months in advance, said UNSW Associate Professor Andrea Taschetto, a co-author of the study. Researchers also used machine learning to examine compound hot-dry events, which can increase wildfire risks, damage ecosystems, and threaten human health, food security, and water supplies.

The researchers emphasized that the seven-month predictive relationship applies specifically to extreme heat, not to forecasts of combined heat and drought. The predictability of compound events varied significantly by season and region, with useful signals generally limited to shorter timeframes.