Frontal structure in the southern Yellow Sea in winter

Abstract

A tongue shape thermohaline front between the warm and saline Cheju Warm Current Water and the cold and fresh Yellow Sea Cold Water is the identical feature in the southern Yellow Sea in winter. The front is closely related on the intrusion of warm and saline water, known as the Yellow Sea Warm Current, into the Yellow Sea from the East China Sea. The upwind-flow theory by strong northerly wind has been believed as a conceptual mechanism for the northward intrusion of the warm and saline water. Observation results in 2002, 2003 winter show that there is the westward flow along the thermohaline front of east-west direction. The westward flow is explained by the thermal wind process. The warm and saline Cheju Warm Current Water is denser than the cold and fresh Yellow Sea Cold Water. In wintertime, the two water mass are boarded each other, the interface of them forms tilted front in vertical by the geostrophic adjustment. In this case, theoretically, a westward thermal wind should be induced in upper layer, while a eastward flow should be induced in lower layer. At this time, the denser Cheju Warm Current Water places in lower layer, therefore water column has reversed temperature profile. The reversal structure of temperature is often observed in this area during winter to spring because this structure is relatively stable by the double-diffusion layering process. Conclusionally, it is harsion of warm and saline water, known as the Yellow Sea Warm Current, into the Yellow Sea from the East China Sea. The upwind-flow theory by strong northerly wind has been believed as a conceptual mechanism for the northward intrusion of the warm and saline water. Observation results in 2002, 2003 winter show that there is the westward flow along the thermohaline front of east-west direction. The westward flow is explained by the thermal wind process. The warm and saline Cheju Warm Current Water is denser than the cold and fresh Yellow Sea Col