Enhanced influence of tropical Atlantic variability on East Asian summer monsoon in warming climate

The spring North tropical Atlantic (SNTA) sea surface temperature (SST) anomalies act as a critical precursor to the East Asian summer monsoon (EASM) and East Asian climate variability. However, how the influence of SNTA SST on the EASM changes in a warming climate remains unclear. Here, using multiple climate model simulations, we demonstrate a significant intensification of the impact of SNTA SST on EASM and East Asian climate under greenhouse warming. In a warmer climate, atmospheric and precipitation responses over East Asia to SNTA SST anomalies are remarkably amplified, contributing to a higher frequency of extreme EASM events following SNTA SST anomalies. Greenhouse warming increases SNTA SST variability, which enhances the response of tropical Indian Ocean SST anomalies via atmospheric teleconnection, thereby strengthening the impact on EASM through the stimulation of anomalous anticyclone over tropical western North Pacific. Meanwhile, a wetter tropical Pacific mean state in a warmer climate further amplifies the influence of SNTA SST-induced tropical central Pacific SST anomalies on the EASM. Our findings suggest that under continued greenhouse warming, the EASM will be increasingly modulated by SNTA SST, providing an opportunity to improve the predictability of East Asian climate.