We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Unusual Cross‐Shelf Transport Driven by the Changes of Wind Pattern in a Marginal Sea.
- Authors
Yao, Zhigang; Chen, Ke; Ding, Yang; Lin, Xiaopei; Bao, Xianwen; Qiao, Lulu
- Abstract
The traditional understanding of the regional circulation in the Northwest Pacific marginal seas is that the Korean Coastal Current flows southward, following the isobaths of 20–50 m. However, an unusual tongue‐shaped structure of cold water is observed in satellite SST data in January 2017, indicating a possible offshore spread of cold coastal water into the middle Southern Yellow Sea (SYS). Additional observations, including in situ hydrographic data as well as direct current measurement, also suggest this cross‐shelf transport of the Korean Coastal Water in January 2017. Our analysis shows that this flow breaks through the isobaths at ∼37°N, moves southward between 50–75 m, and eventually veers anti‐cyclonically at ∼35°N to join the western slope of the SYS. This circulation pattern is further supported by heat budget analysis. Diagnosis of potential vorticity (PV) reveals that the elevated negative PV anomaly imposed by surface wind stress favors this unusual cross‐shelf transport. The change of wind pattern, although under a deceasing wind speed condition, plays an important role. This work provides an alternative view of the wintertime circulation pattern and motivates future studies of the variability of the coastal currents over interannual and longer time scales in the SYS. Plain Language Summary: Cross‐shelf coastal currents are key conduits of marginal seas to the open ocean, and are important not only for hydrographic setup, but also biogeochemical processes such as the distribution of nutrients, ecosystems, and pollutants. In the Northwest Pacific marginal seas, the coastal water usually flows along the west coast of the Korean peninsula in a form of coastally trapped cold water band. However, in January of 2017, satellite observations reveal an anomalous offshore sandwiched cold tongue structure. This paper describes this unusual cross‐shelf flow using observations from multiple platforms, and shows that the Korean coastal water (KCW) from the north of ∼37.5°N diverts into the middle Southern Yellow Sea. This work offers an alternative view of the wintertime pathway of KCW. The finding can provide useful insight for the biogeochemical processes in this region. Key Points: An unusual cold tongue in January of 2017 suggests an offshore transport of cold Korean Coastal Water into the middle shelfAnalysis of a variety of observations and reanalysis confirms the existence of the cross‐isobath transport and reveals its pathwayThe negative Potential Vorticity anomaly drives the cold water diversion when the subtle change of wind direction may play a key role
- Subjects
YELLOW Sea; TERRITORIAL waters; OCEAN circulation; BATHYMETRY; BIOGEOCHEMICAL cycles
- Publication
Journal of Geophysical Research. Oceans, 2021, Vol 126, Issue 11, p1
- ISSN
2169-9275
- Publication type
Article
- DOI
10.1029/2021JC017526