Positive AMO–La Niña synergy enhances recent East Asian dust activity via hydrothermal anomalies

Despite weakening mid-latitude winds under global warming suggesting a decline, East Asian dust activity has unexpectedly rebounded since 2000. We demonstrate this resurgence is driven by the synergy between the Atlantic Multidecadal Oscillation (AMO) positive phase and La Niña, explaining 78% of dust variance. Integrating observations and simulations, we reveal that the dominant driver of recent dust enhancement has shifted from dynamical factors (wind) to hydrothermal anomalies. The cross-basin synergy of the AMO positive phase and La Niña creates a hydrothermal background in the East Asian interior characterized by a "cold winter, warm spring" pattern accompanied by persistent drought. This pattern intensifies the soil freeze-thaw cycle and surface drying, significantly enhancing surface erodibility, thereby becoming the dominant factor for extreme dust outbreaks. Through a closed-loop evidence chain (phenomenon identification, mechanism attribution, and model verification), we clarify how cross-basin climate synergy affects regional dust. These findings provide a robust foundation for seasonal-to-decadal prediction of East Asian dust activity.