The El Niño-Southern Oscillation (ENSO) is one of the most important air-sea coupling systems with global impacts. The regime shift of ENSO properties across the late 1990s has been reported by substantial studies. Understanding influences of the changed ENSO has important implications for extratropical climate variability. This study reveals an amplifying impact of ENSO on the Alaska’s surface air temperature in spring since 1999/2000. The typical pattern in the tropical Pacific sea surface temperature anomaly (SSTA) linking with ENSO shifts from an equatorial eastern Pacific (EP) type to a central Pacific (CP) one. Align with such westward shift in the associated SSTA centers after 2000, a stronger and better-organized atmospheric teleconnection originating from the tropical Pacific towards the Arctic Pacific sector is observed. More significant meridional wind anomalies in Alaska induced by the CP-type ENSO then result in the local warming or cooling via the temperature advection process. Numerical experiments performing in the Linear baroclinic model (LBM) underpin the aforesaid physical processes. Further sensitive simulations suggest that the relative zonal distance between the anomalous heat sink and source in the tropical Pacific associated with ENSO determines the strength of the heat-induced atmospheric teleconnection. Thus, it is important to consider the spatial configuration of the ENSO-related SSTAs in the whole tropical Pacific, with a view to comprehensively understanding the global effects of the late-1990s changes in ENSO.

ENSO,Interdecadal variability,Teleconnections