Multidecadal modulations of the low‐frequency climate variability in the wintertime North Pacific since 1950

Abstract

AbstractThe North Pacific decadal variability (PDV) is known to manifest itself as two distinct spatial patterns. Observations since 1950 reveal that the wintertime PDV underwent notable modulations of their dominance in sea surface temperature (SST) variability and accompanying atmospheric variability. Until the 1980s, decadal SST variability was strongest along the subarctic frontal zone (SAFZ), the boundary between the warm Kuroshio and cool Oyashio waters. The SAFZ variability was highly correlated with decadal variability of the surface Aleutian Low but not simultaneously with tropical SST variability. Since the 1990s, however, this extratropical ocean‐atmosphere variability has lost its predominance, taken over by SST variability in the subtropical frontal zone. It accompanies subtropical anticyclone variability, exhibiting significant anticorrelation with tropical SST variability. These long‐term PDV modulations have remotely modulated temperature variability over Canada and Alaska. Similar PDV modulations are simulated in a centennial integration of a global climate model.