Enhanced impact of the Aleutian Low on increasing the Central Pacific ENSO in recent decades

Abstract In this study, we reveal a marked enhanced impact of the early-spring Aleutian Low (AL) on following winter El Niño and Southern Oscillation (ENSO) after late-1990s. This AL may have an important contribution to increased emergence central Pacific ENSO during recent decades. After late-1990s, decrease (increase) in strength tends induce anomalous cyclone (anticyclone) over subtropical North via wave-mean flow interaction. The associated westerly (easterly) wind anomalies south side tropical western contribute occurrence Pacific-like (La Niña) Bjerknes feedback. Further, leads sea surface temperature (SST) increase (decrease) equatorial summer wind-evaporation-SST (WES) feedback, which further contributes succeeding Niña). Enhanced is attributable enhancement mean circulation Pacific, interaction strengthened WES feedback results offer potential advance our understanding factors for reduced prediction skill since