Wintertime frontal structure and circulation at the Yellow Sea Entrance

Abstract

In winter, a tongue-shaped thermohaline front is established at the Yellow Sea (YS) entrance where the Cheju Warm Current (CWC) water, originating in the Kuroshio, and the YS cold water meet together. The frontal circulation as well as frontal structure has been investigated using comprehensive CTD data and satellite-tracked float tracks. The front develops by the westward advance of the CWC water, but it is bounded by the shallow Changjiang Banks (CB) to the west. In the northern part of the tongue-shaped frontal zone, isotherms, isohalines and isopycnals are downward declined toward the north, showing that the dense CWC water lies under the lighter YS cold water mass. A cyclonic circulation is formed around the tongue-shaped front, which consists of a westward transversal current (TC) along 34° N and a southeastward outflow along the 50-m isobath of the CB. The new observational findings of the cyclonic circulation and the TC do not match the classical paradigm of a northerly wind-driven circulation which consists of the northward inflow through the central trough and the southward outflow on the coastal sides.tal structure has been investigated using comprehensive CTD data and satellite-tracked float tracks. The front develops by the westward advance of the CWC water, but it is bounded by the shallow Changjiang Banks (CB) to the west. In the northern part of the tongue-shaped frontal zone, isotherms, isohalines and isopycnals are downward declined toward the north, showing that the dense CWC water lies under the lighter YS cold water mass. A cyclonic circulation is formed around the tongue-shaped front, which consists of a westward transversal current (TC) along 34° N and a southeastward outflow along the 50-m isobath of the CB. The new observational findings of the cyclonic circulation and the TC do not match the classical paradigm of a northerly wind-driven circulation which consists of the northward inflow through the central trough and the southward outflow on the coastal sides.