Influence of tropical Atlantic sea surface temperature anomalies on the East Asian summer monsoon

This study investigates the relationship between tropical Atlantic (TA) sea surface temperature (SST) anomalies and the East Asian summer monsoon (EASM), as well as the possible mechanism by which TA SST anomalies affect the EASM. We demonstrate a robust positive simultaneous correlation between the boreal summer TA SST anomalies and the EASM. Observational and model-based studies identify an atmospheric teleconnection in which the summer TA warming can enhance convection and induce low-level convergence in the Atlantic basin, which alters the Walker circulation and produces a sinking motion and divergence in the central Pacific. As a Rossby response to the anomalous divergence, an anomalous anticyclonic pair is generated over the western Pacific. As a result, the EASM is strengthened. Additionally, a significant lag correlation of the EASM with TA SST anomalies from the previous boreal spring is demonstrated, which implies potential applicability of the TA SST factor to the EASM prediction at seasonal time-scales.