Winter‐to‐Winter Sea Surface Temperature Anomaly Reemergence in the Yellow Sea

Abstract The reemergence of winter sea surface temperature anomalies (SSTAs) serves as an effective oceanic memory mechanism, linking winter SSTs across consecutive years in mid‐latitude deep oceans. However, its existence and potential role in modulating SSTA variability in continental shelf seas have remained largely unexplored. Using extensive satellite and in situ observations combined with high‐resolution numerical simulations, this study provides the first evidence of robust winter‐to‐winter SSTA reemergence in the seasonally stratified Yellow Sea (YS). We find that in the central YS, SSTAs from late winter show significant positive correlations with those in the following autumn and winter. This consistent SSTA recurrence pattern is observed in 55% of the years from 2003 to 2024 and is spatially confined to the deep central basin of the YS. Our findings indicate that atmospheric forcing anomalies have minimal impact on this recurrence. Instead, numerical experiments and mixed‐layer heat budget analyses reveal that the winter‐to‐winter SSTA recurrence is driven using the intrinsic oceanic reemergence process. This process involves four stages: anomalous winter temperatures penetrate the vertically mixed water column; this signal is then sequestered below the seasonal thermocline within the YS Cold Water Mass, insulated from surface forcing throughout the summer; the signal is re‐entrained into the deepening surface mixed layer during autumn and early winter; and finally, the reemerged SSTA is formed. This subsurface thermal memory pathway offers a new basis for improving seasonal‐to‐interannual water temperature predictability in the YS and provides a framework applicable to other seasonally stratified shelf seas.