An Observational Analysis of the Relationship Between Wind and the Expansion of the Changjiang River Diluted Water during Summer

This paper presents an analysis of the impact of wind on the transport of the Changjiang River Diluted Water (CRDW) in August by using the salinity data collected on two zonal sections near Cheju-do. Based on the climatological mean conditions and four extreme events, the analysis indicates that wind-induced Ekman transport plays an important role in the extension of the CRDW. The strong northeastward Ekman transport induced by southeasterly wind in 1996, 2003, 2004, and 2006 pushes the core of the CRDW to the sea adjacent to Cheju-do. A comparison of the wind variation before observation among these four extreme events indicates that the expansion pattern of the CRDW is primarily changed by synoptic variation with timescales of days to weeks, such as during a typhoon. The weak eastward extension of the CRDW in 2004, accompanied with a relatively strong southerly wind, implies that the oceanographic state (e.g., the depth of halocline) may strongly affect the impact of wind on the extension of the CRDW.