Ocean Circulation Dynamics in the East/Japan Sea

The East/Japan Sea is a semi-enclosed marginal sea bounded by the Korean Peninsula, Japanese archipelago and Russian Far East. Its circulation is governed by the inflow of warm, saline waters from the Kuroshio extension through the Tsushima Strait, which branches into the Tsushima Current and the East Korean Warm Current. These form a cyclonic gyre system that interacts with a subpolar frontal band separating warm subtropical waters from cold subpolar waters. Seasonal monsoons drive variable wind stress and surface cooling, leading to convective mixing in winter and stratification in summer. The basin’s complex bathymetry and narrow straits generate mesoscale eddies, jets and topographic waves that modulate heat, salt and nutrient transport. Water-mass structures include a thin, well-mixed surface layer, intermediate waters of modified Tsushima origin and deep, oxygen-rich bottom waters. This circulation influences regional climate variability, supports high marine productivity and underpins fisheries, while also acting as a conduit for carbon and biogeochemical cycles with global significance.

Research from Nature Portfolio

Recent studies have employed in situ glider measurements and numerical models to trace low-salinity plumes derived from river discharge as they interact with mesoscale eddies and are advected far offshore. Findings demonstrate that springtime coastal waters propagate beyond the continental shelf, altering stratification and enhancing chlorophyll-a concentrations in the open sea. This work advances understanding of coastal–offshore exchange, nutrient transport and the role of freshwater in modulating biological productivity and elemental cycles in the region.

Ocean Circulation Dynamics in the East/Japan Sea publication trend

The graph below shows the total number of articles in ocean circulation dynamics in the east/japan sea across all publications each year (not limited to Nature Index journals).

Technical terms

Mesoscale eddy: A rotating water mass typically 10–100 km in diameter that influences local currents, mixing and transport of heat and nutrients.

Tsushima Current: A branch of the Kuroshio that flows northward through the Tsushima Strait into the East/Japan Sea, carrying warm, saline water.

Sea surface temperature anomaly (SSTA): The departure of sea surface temperature from its long-term average, indicating warming or cooling trends.

Sea surface height anomaly (SSHA): The deviation of sea surface elevation from mean sea level, reflecting ocean dynamics and mass distribution.

Topographic Rossby wave: A large-scale wave guided by bottom topography, affecting sea level and current propagation along continental slopes.

References

1. Climatological Atlas of Temperature and Salinity for the Northeast Asian Seas. Scientific Data (2025).
2. Freshwater spreading far offshore the Japanese coast. Scientific Reports (2024).
3. Exploring Long-Term Persistence in Sea Surface Temperature and Ocean Parameters via Detrended Cross-Correlation Approach. Remote Sensing (2024).
4. Increasing trend in Japan Sea Throughflow transport. Journal of Oceanography (2020).