Chinese Journal of Oceanology and LimnologyVol. 33 No. 3, P. 779-789, 2015http://dx.doi.org/10.1007/s00343-015-4210-y Interannual salinity variability of the Northern Yellow Sea Cold Water Mass* LI Ang (李昂) 1, 2 , YU Fei (于非) 1 , ** , DIAO Xinyuan (刁新源) 1 1 Institute of Oceanology , Chinese Academy of Sciences , Qingdao 266071 , China 2 University of Chinese Academy of Sciences , Beijing 100049 , China Received Aug. 1, 2014; accepted in principle Sep. 30, 2014; accepted for publication Oct. 21, 2014 © Chinese Society for Oceanology and Limnology, Science Press, and Springer-Verlag Berlin Heidelberg 2015 Abstract This paper discusses the interannual variability of the Northern Yellow Sea Cold Water Mass (NYSCWM) and the factors that infl uence it, based on survey data from the 1976–2006 national standard section and the Korea Oceanographic Data Center, monthly E-P fl ux data from the European Centre for Medium-Range Weather Forecasts, and meridional wind speed data from the International Comprehensive Ocean-Atmosphere Data Set. The results show that: 1) the mean salinity of the NYSCWM center has a slightly decreasing trend, which is not consistent with the high salinity center; 2) both the southern salinity front and the halocline of the NYSCWM display a weakening trend, which indicates that the difference between the NYSCWM and coastal water decreases; 3) the Yellow Sea Warm Current intrusion, the E-P fl ux of the northern Yellow Sea, and the strength of the winter monsoon will affect the NYSCWM salinity during the following summer. Keyword : Northern Yellow Sea Cold Water Mass (NYSCWM); salinity; interannual variability; linear trend 1 INTRODUCTION The Yellow Sea (YS) is located at 31°40′–39°50′N, 119°10′–126°50′E, between the Chinese mainland and the Korean Peninsula. It is a semi-closed shallow sea shaped like a reverse “S”. The northwestern YS is linked with the Bohai Sea through the Bohai Strait, and the southern YS opens to the East China Sea. The mean depth of the YS is 44 m and the maximum depth is 140 m. A long and narrow depression, known as the YS Trough, is located at the center of the YS between 34°–38°N and 124°–125°E. A line from Chengshantou of the Shandong Peninsula to Jangsan of the Korean Peninsula divides the YS into a northern and southern section. With a mean depth of 38 m, the northern YS is shaped like a parallelogram basin that is fl at in the center and inclines to the south. Because of the infl uence of the East Asian Monsoon, the north wind prevails in the winter and the south wind prevails in the summer over the YS area. The Yellow Sea Cold Water Mass (YSCWM) is one of the prominent oceanographic phenomena in the YS. The two centers of the YSCWM are the Northern Yellow Sea Cold Water Mass (NYSCWM) and the Southern Yellow Sea Cold Water Mass (SYSCWM) (Tang, 2005). With low temperature and high salinity, the YSCWM has a stronger temperature and salinity front in the YS, and usually occupies the deep and bottom layers of the trough of the central YS. The YSCWM has a great impact on the distribution of the biocenose and the acquisition of fi shery resources (Du et al., 1996; Wang et al., 2003; Zhang et al., 2007). The YSCWM has clear seasonal variability based on in-situ observations and numerical simulations. With the seasonal change of the thermocline, the YSCWM forms in the spring (approximately in May), matures in the summer (approximately in August), recedes in the autumn, and completely disappears in winter (Guan, 1963; Chu et al., 1997; Yu et al., 2006; Zhang et al., 2008; Bao et al., 2009; Yao et al., 2012). During the cooler season (from September to * Supported by the National Natural Science Foundation of China (Nos. 41176018, 41376031), the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDA11020301), and the NSFC-Shandong Joint Fund for Marine Science Research Centers (No. U1406401) ** Corresponding author: yuf@qdio.ac.cn
