Subseasonal Variation in the Winter ENSO-NAO Relationship and the Modulation of Tropical North Atlantic SST Variability

The impact of El Niño–Southern Oscillation (ENSO) on the North Atlantic (NAO) has been controversially discussed for several decades, which exhibits prominent seasonality and nonstationarity. During early winter, there appears a positive ENSO-NAO relationship, while this relationship reverses its sign in late winter. Here, we show that subseasonal variation could be attributed to different mechanisms involved winters. In linkage between ENSO NAO simply understood as resulting from changes tropical Walker circulation associated atmospheric meridional over Atlantic. following an opposite NAO-like response large-scale Pacific–North teleconnection pattern fully establishes evident sea surface temperature anomalies occur Tropical (NTA). We further phase shift during winter is largely contributed by establishment ENSO-associated NTA SST anomaly via excited convection subtropical competing roles explain providing useful information seasonal prediction Atlantic–European region.