A numerical study on the Changjiang diluted water in the Yellow and East China Seas

[1] A numerical simulation is performed using the Princeton Ocean Model (POM) to investigate the behavior of the Changjiang Diluted Water (CDW), and to evaluate the freshwater budget in the Yellow and East China Seas. In addition, the major process controlling the behavior of the CDW is discussed. The simulated CDW distributions are fairly consistent with the observed distributions, showing a remarkable seasonal variation. The CDW extends to the northeast toward the Tsushima/Korea Straits during summer, while it hugs the Chinese coast to the southwest within a narrow band in winter. Tracer experiment is carried out to track the freshwater originating only from the Changjiang, and to evaluate the freshwater budget in the Yellow and East China Seas. The result shows that about 68 percent of the Changjiang discharge is transported through the Tsushima/Korea Straits, and that about 27 percent is transported through the Taiwan Strait in autumn and winter. To investigate the main process controlling the behavior of the CDW mentioned above, another experiment is carried out without wind-forcing. It is found that the eastward extension of the CDW is strongly constrained by the “Taiwan-Tsushima Warm Current System” over the shelf regime. The wind is, however, responsible for the northeastward extension of the CDW in summer. In addition, the southwestward extension at the Taiwan Strait during winter is done by strong northeasterly monsoon. The experiment without wind-forcing shows that freshwater transport through the Tsushima/Korea Straits increases to 90 percent of the total Changjiang discharge.

[1]  D. Nof.  China's Development Could Lead to Bottom Water Formation in the Japan/East Sea , 2001 .

[2]  Gregg A. Jacobs,et al.  Connectivity of the Taiwan, Cheju, and Korea straits , 2003 .

[3]  R. Limeburner,et al.  Identification of Water Masses in the Yellow Sea and the East China Sea by Cluster Analysis , 1991 .

[4]  Kuang-Lung Fan.  The Branch of Kuroshio in the Taiwan Strait , 1984 .

[5]  A. Isobe.  The Taiwan-Tsushima Warm Current System: Its Path and the Transformation of the Water Mass in the East China Sea , 1999 .

[6]  G. Mellor,et al.  Development of a turbulence closure model for geophysical fluid problems , 1982 .

[7]  Heung-Jae Lie,et al.  On the origin of the Tsushima Warm Current , 1994 .

[8]  Hiroshi Ichikawa,et al.  Seasonal variation of heat and freshwater transports by the Kuroshio in the East China Sea , 2000 .

[9]  Hu Dun-xin.  Some Striking Features of Circulation in Huanghai Sea and East China Sea , 1994 .

[10]  R. Beardsley.  Lagrangian flow observations in the East China,Yellow and Japan Seas (Proceedings of the Sixth Japan and East China Seas Study Workshop,22-27 April 1991,Fukuoka,Japan) , 1992 .

[11]  Shenn-Yu Chao,et al.  Seasonal variation of the circulation in the Taiwan Strait , 2002 .

[12]  I. Pang,et al.  Seasonal Variation of Water Mass Distributions in the Eastern Yellow Sea and the Yellow Sea Warm Current , 1998 .

[13]  R. Duce,et al.  Input of atmospheric trace elements and mineral matter to the Yellow Sea during the spring of a low‐dust year , 1992 .

[14]  Temporal and spatial scales of the Yellow Sea thermal variability , 1997 .

[15]  Low-Frequency Temperature Variability at Fukue Island Located Southwest of the Tsushima Straits , 2000 .

[16]  O. Katoh,et al.  Current distributions in the southern East China Sea in summer , 2000 .

[17]  Su Yu-song,et al.  Water Masses in China Seas , 1994 .

[18]  A. Morimoto,et al.  Seasonal variation in surface circulation of the East China Sea and the Yellow Sea derived from satellite altimetric data , 1997 .

[19]  R. Limeburner,et al.  Comparison of winter and summer hydrographic observations in the Yellow and East China Seas and adjacent Kuroshio during 1986 , 1994 .

[20]  C. Chern,et al.  On the Kuroshio Branch in the Taiwan Strait During Wintertime , 1988 .

[21]  G. Fang,et al.  Water Volume Transport Through the Taiwan Strait and the Continental Skelf of the East China Sea Measured with Current Meters , 1991 .

[22]  Robert C. Beardsley,et al.  Discharge of the Changjiang (Yangtze River) into the East China Sea , 1985 .

[23]  W. Large,et al.  Open Ocean Momentum Flux Measurements in Moderate to Strong Winds , 1981 .

[24]  Robert L. Haney,et al.  On the Pressure Gradient Force over Steep Topography in Sigma Coordinate Ocean Models , 1991 .

[25]  T. Senjyu,et al.  Freshwater and temperature transports through the Tsushima-Korea Straits , 2002 .