North Pacific capacitor effect bridges spring Tibetan Plateau heating and the East Asian summer monsoon

The East Asian summer monsoon (EASM) arises from complex land–air–sea interactions, shaped by influences from the Tibetan Plateau to the west and the Pacific Ocean to the east. Using in situ observations, reanalysis data and simulations from the Community Earth System Model version 2.1.3, here we show that North Pacific sea surface temperature anomalies (SSTAs) act as a seasonal capacitor, mediating the delayed impact of spring (March–May, MAM) Tibetan Plateau surface sensible heating (TPSH) anomalies on EASM. Enhanced MAM TPSH excites Rossby waves that drive an anticyclonic circulation, establishing a persistent “warm-central/cold-flanks” SSTA pattern in the North Pacific. These SSTAs strengthen the summer subtropical front and atmospheric baroclinicity, energizing transient eddies. The resultant cyclonic–anticyclonic circulation anomalies enhance low-level moisture convergence, intensifying rainfall from the Yangtze–Huaihe River basin to southeastern Japan. This capacitor effect facilitates a cross-seasonal linkage by converting spring-initiated TPSH anomalies into basin-scale summer circulation adjustments through oceanic thermal inertia-driven storage.