Subtropical Jet Wave Train Associated With North Atlantic SST Contributes to ENSO-Like Anomalies

El Niño-Southern Oscillation (ENSO) is the dominant atmosphere‒ocean coupling system over equatorial Pacific and has substantial influences on global climate/weather. Here, we find that the west‒east sea surface temperature (SST) gradient over the northeastern Atlantic can influence the remote development of ENSO through the wave train along the subtropical westerly jet in boreal winter. Specifically, a positive SST gradient favors a positive precipitation anomaly over the northeastern Atlantic by inducing a cyclonic anomaly. Diabatic heating induced by anomalous rainfall excites an anticyclonic response in the upper troposphere, which propagates eastward along the subtropical westerly jet and eventually leads to an anticyclonic anomaly over the eastern tropical Pacific. This anticyclonic anomaly tends to cause an anomalous divergence there, which promotes atmospheric convection. As a result, the low-level westerly winds over the equator strengthen (i.e., 850 hPa), contributing to the development of an El Niño-like SST anomaly.