양쯔강 담수의 이동 확산

Abstract

The influence of tides and winds on the mixing and dispersal of the Changjiang Di-luted Water (CDW) is investigated using ROMS model in summer monsoon of 2003. Saline waters in the Yellow Sea, related to the Changjiang River estuary and plume, has been thoroughly investigated by the ROMS (the Regional Ocean Modeling System) si-mulations. The model is forced with realistic winds, tides, and river flow to produce a 3-month-long hindcast of the summer of 2003. This period covers the time of natural dis-charge of Changjiang River during the summer before the construction of Three-Gorge Dam. This study focuses on the generation, pathway, and forms of CDW (Changjiang Diluted Water) dispersion in meander, patch, and lens structures, as reported in many field observations. The scale of patches ranges from 50 km to 150 km in the horizon and from 10 m to 20 m thick. During the summer of 2003, the life span has been estimated as approximately 20 days from generation of meander to fade out of lens pattern. The moving speed of patch core has been estimated as approximately 40 cm/s along the ma-jor axis of meander with the life span of 10 to 20 days dependent upon the local winds and tidal action. Through the numerical drifter experiment and vorticity field, the local winds and tidal actions are very important agents that competitively control the meand-er, patch, and lens structures of the CDW.