Global Increases in Dry‐Wet Abrupt Alternation Events Under Climate Change

Rapid transitions between dry and wet phases increasingly threaten global water resources and ecosystem sustainability. However, how the terrestrial water storage (TWS)–a key determinant of water and energy budgets–modulates these dry‐wet abrupt alternation (DWAA) events remains poorly understood. Here, we leverage a recently reconstructed long‐term TWS data set to evaluate global dynamics of DWAA events, and explore their teleconnection relationships with El Niño‐Southern Oscillation (ENSO). We find that the frequency of DWAA events has increased more than three‐fold during the past 4 decades (1979–2022), driven by heightened variability of atmospheric moisture transport and circulation dynamics. ENSO plays an essential role in modulating these transitions, with the La Niña phase in particular enhancing both the coverage and intensity of these events. These findings suggest an amplified risk of hydroclimatic extremes under climate warming, highlighting the urgent need to improve monitoring and prediction of these rapid transitions.