Abstract
The Western part of the East/Japan Sea (WES) has warmed rapidly in recent decades, yet the mechanisms of its recent reorganization remain unclear. Using 1990–2024 observations, we identify a likely winter sea surface temperature (SST) regime shift around 2015, supported by complementary non-parametric change-point and persistence diagnostics and by the persistence of positive anomalies thereafter. Before 2015, SST variability reflected a balance between atmospheric forcing and East Korea Warm Current (EKWC) transport; afterward, EKWC-related variability and a northward Kuroshio displacement became more prominent, concurrent with a meridional reorganization of the Aleutian Low. Despite stable chlorophyll-a, phytoplankton size structure shifted toward pico-dominance at the expense of nano-classes, consistent with enhanced stratification and potentially altered nutrient supply pathways. These results suggest that teleconnection-driven boundary-current variability may increasingly shape both physical and biological variability in this marginal sea, highlighting its role as a sentinel of basin-scale Pacific decadal variability and its relevance for inter-basin climate linkages and decadal prediction.
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Acknowledgements
This study used publicly available data from the Korea Oceanographic Data Center (KODC), accessible at https://www.nifs.go.kr/kodc/eng/index.kodc.
Funding
This research was funded by the National Institute of Fisheries Science (“Assessment of Impacts and Development of a Prediction System for Climate Change in Fisheries”; R2026044) and by the Korea Institute of Marine Science & Technology Promotion (KIMST), funded by the Ministry of Oceans and Fisheries (RS-2026-25540332).
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Jung, H.K., Lee, C.I., Jang, H.K. et al. Teleconnection-driven winter sea surface temperature regime shift and ecosystem reorganization in the western part of the East/Japan Sea.
Sci Rep (2026). https://doi.org/10.1038/s41598-026-55134-3
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DOI: https://doi.org/10.1038/s41598-026-55134-3
Source: Ecology - nature.com
