A WIND-DRIVEN YELLOW SEA WARM CURRENT?

Observations of current velocity, pressure, and temperature in the eastern Yellow Sea during January 10 to April 12, 1986, and geostrophic winds calculated from surface pressure distributions, are analyzed for a study of the synoptic band response of the Yellow Sea to the wintertime winds. Currents in shallow coastal waters along a straight portion of the coast are mostly downwind to the south. Along the northern coast sheltered by a large bay, the current is persistently northward. This could be the result of a domination by geostrophic currents associated with an offshore-directed density gradient which is known to form in areas around this location. In the Yellow Sea trough, strong upwind flows are found to follow closely surges in the north wind. Co-spectral analyses show that these events are driven by a longitudinal pressure gradient associated with the sea-level set-up along the west coast of South Korea under a prevailing north wind.