珠江口及邻近海域潮汐环流数值模拟Ⅱ——河口水交换和物质输运分析  

Three-Dimensional High-Resolution Numerical Study of the Tide and Circulation in the Pearl River Estuary and Its Adjacent Waters Part II:Estuarine Mass Transport and Water Exchange

作　　者：丁芮[1] 陈学恩[1] 曲念东[2] 

机构地区：[1]中国海洋大学海洋与大气学院,山东青岛266100 [2]国家海洋局南海环境监测中心,广东广州510300

出　　处：《中国海洋大学学报（自然科学版）》2016年第7期1-10,共10页Periodical of Ocean University of China

基　　金：海洋公益性行业科研专项"小型阵变频高频地波雷达数据的开发和应用"(201205032-2);"海底管道探测技术集成及风险评估技术研究与示范应用"(201305026-3)资助~~

摘　　要：采用无结构网格三维有限体积海洋模式FVCOM所建立的珠江口及邻近海域的三维正压高分辨率数值模型,对珠江口水域的水交换和物质输运过程进行了研究。研究发现,只考虑潮汐作用时,珠江口内湾水交换能力很弱,海水滞留时间在90d以上;加入径流、风应力作用后内湾水交换能力变强,示踪物的滞留时间分布大体上在珠江口航道区以及河口西侧(靠近珠江口门处)较短,在河口东侧(远离珠江口门处)和西侧浅滩较长。在丰水期,西南风驱动下河口示踪物平均浓度最低,为0.34,滞留时间最短,自西向东由10d逐渐过渡为90d以上。对不同海域之间的水交换分析表明,珠江河口内4大口门以及伶仃洋海区、磨刀门海区水交换能力最强;深圳湾、大鹏湾、大亚湾与口门外陆架海域的水交换能力较弱。粒子追踪试验表明,珠江口内粒子在枯水期会进入黄茅海,在丰水期则可抵达大亚湾和大鹏湾。径流和风应力作用会不同程度加大珠江口海域不同口门处粒子位移,在枯水期粒子向西运动,洪奇门、磨刀门与鸡啼门处粒子位移最大,90d内可达285km;在丰水期粒子向东运动,横门处粒子位移最大,90d内可达190km,部分可至大亚湾和大鹏湾,且粒子运动呈螺旋状推进。Based on an unstructured grid and finite-volume coastal ocean model（FVCOM）,including highly accurate coastline and bathymetry data,a three-dimension model with high resolution is constructed in the Pearl River Estuary and its adjacent sea area to calculate the transport of estuarine mass and the capacity of water exchange.The results indicate that,with an impact of tides,the capacity of the water exchange in the Pearl River Estuary is weak and the residence time of the waters is more than 90 days,.The runoff and the wind stress can enhance the capacity of the water exchange,and the residence time of the dye in the channel and the west（near entrances of the Pearl River）is shorter than that in the western shoal and the east（away from entrances of the Pearl River）.Moreover,during the flood season,the mean concentration of the dye in the estuary maintain low and the residence time of it maintain short,driven by a southwestern wind.The capacities of the water exchange in entrances of the estuary and the sea area of Lingdingyang and Modaomen are strong,while in the sea area of Shenzhen Bay,Daya Bay and Mirs Bay,the capacities of the water exchange are relatively weak.Tracers of the estuary enter Huangmao Sea in the dry season and enter Daya Bay,Mirs Bay in the flood season.With impacts of the runoff and the wind stress,the capacity of the water exchange in the estuary and the velocity with which the tracers in entrances of the estuary transport are both enhanced.In the dry season,tracers move to the west and the maximum displacement is 285 kmin 90days.In the flood season,tracers move to the east and the maximum displacement is 190 kmin 90days.The tracers move forward in a helical way.

关 键 词：数值模拟 珠江口 水交换 滞留时间 FVCOM 

分 类 号：P731.27[天文地球—海洋科学]