Subsurface dissolved oxygen (DO) in the North Pacific is highly sensitive to climate variability, yet the synergistic impacts of multi-scale climate modes on its spatial patterns remain fully to be elucidated. Utilizing a comprehensive suite of multi-source data, including biogeochemical Argo (BGC-Argo) floats and gridded oxygen products, this study investigates the response of subsurface DO to the co-variability of the El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO). High-resolution BGC-Argo profiles reveal that when ENSO and PDO are in phase, the central North Pacific experiences extreme ventilation events and intensified upper-ocean stratification, conrtibuting to the pronounced positive or negative anomalies in subsurface DO. Long-term statistical analysis further uncovers a striking spatial dipole phenomenon that the subsurface DO variations in the central North Pacific and the Gulf of Alaska exhibit strictly opposite phase characteristics. This dipole is dynamically regulated by the Aleutian Low, whose strength and position are jointly modulated by the in-phase alignment of ENSO and PDO. Our findings suggest that climate modes play an important role in modulating regional biogeochemical variations, offering useful insights for understanding ocean deoxygenation trends
 

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