Relationship between the southern Yellow Sea Cold Water Mass and the distribution and composition of suspended particulate matter in summer and autumn seasons

Abstract

The Yellow Sea is an important channel for transporting terrigenous materials from the East Asian continent to the western Pacific Ocean. Within the Yellow Sea, the Yellow Sea Cold Water Mass (YSCWM) is the most typical hydrological phenomenon during the warm half-year. Clarifying the relationship between suspended particulate matter and the YSCWM is a prerequisite for understanding the source-to-sink sedimentary system in the Yellow Sea. This study analyzed the suspended particulate matter concentrations in the southern Yellow Sea in the summer and autumn of 2012 and used conductivity, temperature and depth data collected at 32 hydrographic stations to study the impact of the southern YSCWM (SYSCWM) on suspended particulate matter. In summer, the tidal mixing front, induced by the SYSCWM and tidal mixing, limited the spread of suspended particulate matter from coastal areas to offshore areas, which led to the development of a suspended particulate matter concentration front in sloping areas. The pycnocline obstructed the vertical diffusion of nutrients in the SYSCWM, resulting in a subsurface chlorophyll maximum layer forming in the pycnocline. In autumn, abundant nutrients were released from the SYSCWM due to northerly wind stirring, which promoted the growth of phytoplankton. The wind stirring also deepened the pycnocline, and the pycnocline blocked the upward diffusion of resuspended particulate matter from the bottom. This paper provides a mechanistic model that reveals the relationship between the SYSCWM and suspended particulate matter based on the above conclusions.