ABSTRACT Sea surface temperature (SST) in the western North Pacific (WNP) strongly affects the regional marine ecosystem and modulates East Asian weather. Although the mechanisms of SST variability in the WNP have been extensively examined, it remains unclear how it is influenced by remote forcing from high‐latitude regions. Using reanalysis datasets spanning 1979–2024, this study examined the linkage between the summer atmospheric circulation over northeastern Siberia (NES) and autumn SST variability in the WNP and elucidated the underlying influencing processes. Results revealed that anomalous high pressure over NES in August, concurrent with frequent heat waves, is typically followed by colder autumn SST in the WNP. The ocean cooling is modulated by a low‐pressure system over the WNP, which reduces insolation through increased cloud cover and enhances evaporation via dry air advection. Together, these processes result in net surface heat loss, thereby contributing to subsequent SST cooling. This cooling, plausibly sustained by ocean thermal inertia, persists until November. This linkage, observed only following August heat waves over NES, is facilitated by the oceanic thermal structure characterized by a shallow mixed layer, which enhances the sensitivity of SST to surface heat loss. These findings suggest that the late‐summer atmospheric circulation over NES might be helpful in predicting autumn SST variability in the WNP and provide new insights into the connection between high‐latitude heat extremes and midlatitude SST variability.
Zhou et al. (Tue,) studied this question.