Observational evidence of a warm ocean current preceding a winter teleconnection pattern in the northwestern Pacific

The role of the extratropical ocean in climate remains unclear due to the complexities in air-sea interaction processes. We have found robust evidence for the Tsushima Warm Current (TWC) preceding the western Pacific (WP) teleconnection pattern by conducting an analysis over the past 30 years. The WP index in winter sharply succeeds the volume transport of the TWC in autumn, but rather smoothly connects with the El Niño indices, indicating a considerable role of the ocean current in the climate system. Correlation patterns of seasonal precipitation over the Japanese Islands are also consistent with this relationship. The significant lead-lag correlations with the coherent structures of surface temperature indicate ocean-to-atmosphere feedback in which the interannual variation of the wind-driven current, represented by the TWC transport, influences the regional climate conditions associated with the WP pattern in winter.