El Nino could signal extreme Amazon heat 7 months in advance

A new study published in the journal Earth's Future has found that El Nino patterns and warming in the tropical Atlantic could provide advance warnings of extreme heat across parts of the Amazon Basin as much as seven months before temperatures peak. The research examined how major patterns of natural climate variability influence temperature and rainfall extremes across six distinct Amazon regions using monthly climate data spanning 1950 to 2023, according to the Australian climate research center ARC Centre.

The clearest long-range signal emerged for the March-May period, when extreme Amazon heat was associated with 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 study co-author.

Forecasting limitations

Researchers also employed machine learning techniques to examine compound hot-dry events, which can increase wildfire risks, damage ecosystems and threaten human health, food security and water supplies. The researchers cautioned that the seven-month relationship applies specifically to extreme heat rather than reliable long-range forecasts of combined heat and drought.

Predictability of compound events varied considerably by season and region, with useful signals generally limited to shorter periods. The findings were published Tuesday by the ARC Centre.