Modulation of spring northern tropical Atlantic sea surface temperature on the El Niño‐Southern Oscillation–East Asian summer monsoon connection

Abstract

El Niño‐Southern Oscillation (ENSO) has a large impact on the succeeding East Asian summer monsoon (EASM) variability via modulating the western North Pacific (WNP) anticyclonic anomaly. This study reveals that spring northern tropical Atlantic (NTA) sea surface temperature (SST) has a prominent modulation of the ENSO–EASM relationship. When the spring NTA SST anomalies are of the same sign as the preceding winter equatorial central‐eastern Pacific SST anomalies, the ENSO–EASM connection is strong. The connection between ENSO and EASM becomes very weak when the spring NTA and preceding winter equatorial central‐eastern Pacific SST anomalies are opposite. This result implies that it is crucial to consider the spring NTA SST status when forecasting the EASM based on the winter equatorial central‐eastern Pacific SST. The modulation of spring NTA SST anomalies on the ENSO–EASM relation is through its destructive or constructive contribution to the anomalous anticyclone over the WNP. When the spring NTA SST anomalies and the equatorial central‐eastern Pacific SST anomalies have the same (opposite) signs, the summer WNP anticyclonic anomaly generated by the ENSO was largely enhanced (weakened) by the spring NTA SST‐generated atmospheric anomalies, which result in strong (weak) influence of ENSO on the EASM variability.