Unusual cross‐shelf transport driven by the changes of wind pattern in a marginal sea

The traditional understanding of the regional circulation in Northwest Pacific marginal seas is that Korean Coastal Current flows southward, following isobaths 20–50 m. However, an unusual tongue-shaped structure cold water observed satellite SST data January 2017, indicating a possible offshore spread coastal into middle Southern Yellow Sea (SYS). Additional observations, including situ hydrographic as well direct current measurement, also suggest this cross-shelf transport Water 2017. Our analysis shows flow breaks through at ∼37°N, moves southward between 50–75 m, and eventually veers anti-cyclonically ∼35°N to join western slope SYS. This pattern further supported by heat budget analysis. Diagnosis potential vorticity (PV) reveals elevated negative PV anomaly imposed surface wind stress favors transport. change pattern, although under deceasing speed condition, plays important role. work provides alternative view wintertime motivates future studies variability currents over interannual longer time scales