Water isotopes reveal early drought signals in Central Amazon rainfall

The historic droughts of 2023 and 2024 in the Amazon reduced river flows and altered the region's rainfall composition. Daily monitoring in Manaus, the capital of the Brazilian state of Amazonas, revealed these changes through the use of isotopes, which act as a kind of water "fingerprint." This method demonstrated how El Niño and warming in the North Atlantic affected the origin of moisture and precipitation dynamics.