Upper low salinity water in the Yellow Sea

Abstract

The seasonal distribution of the low salinity water in the Yellow Sea is analyzed based on conductivity-temperature-depth (CTD) data obtained during 1996-1998. The CTD data reveal that a core of low salinity water is formed in the surface layer of the southern Yellow Sea in summer. This fresh water mass appears to originate mainly from the China coastal waters including the Yangtze River diluted water. It moves like a single body to adjust the rearranged basin-scale pressure field with maintaining the fresh water signal for about ten months. The seasonal distribution of the low salinity water exhibits a well-posed annual cycle in its location; it moves to the west in fall, to the south in early winter and then stays in the Yangtze Bank until late spring. This annual cycle is a key component of the variation of the seasonal circulation in the Yellow Sea as well as the lateral fluctuation of the warm and saline water in the northwest and southeast direction in winter and summer, respectively.