Daily monitoring in Manaus, Brazil, has revealed that historic droughts in 2023 and 2024 altered the region's rainfall composition by reducing river flows. Isotopes used as water 'fingerprints' show how El Niño and North Atlantic warming impacted moisture origins.

The Central Amazon faces heightened vulnerability due to these climatic shifts, which have long-term implications for regional ecosystems and communities dependent on stable water supplies.

This method of using isotopes provides early signals of drought onset, crucial for developing adaptive strategies in the face of increasing climate variability.