Temperature and Salinity Long-term Variation Trend of Southern Yellow Sea Cold Water Mass

This result discusses the temperature and salinity long-term variation trend of the Southern Yellow Sea Cold Water Mass (SYSCWM) and examines the factors and mechanisms that influence SYSCWM, based on hydrographic datasets of the China national standard section and the Korea Oceanographic Data Center. Surface air temperature and meridional wind speed data is used to describe the seasonal situation. The mean temperature and salinity of SYSCWM has different long-term variation trends. West center temperature of SYSCWM is rising, while east center temperature is falling. The salinity of SYSCWM is declining. The mean temperature of SYSCWM relates to the warm water intrusion of Yellow Sea Warm Current, the winter monsoon, and the winter air temperature. The mean salinity of SYSCWM is affected by Yellow Sea Warm Current intrusion and E-P flux. Summer process plays a primary role in the cooling trend of east center temperature of SYSCWM. Decreasing trend of east part of SYSCWM salinity shows that the warm water intrusion from south may get weaker and the circulation of SYSCWM may get weakened. The weakened circulation of SYSCWM may lead to the decreasing trend of the east center of SYSCWM temperature. Higher SST and weakened circulation of SYSCWM could be seen as two main mechanisms of the cooling trend of east center of SYSCWM temperature.