2006年夏季珠江冲淡水驱动的上升流  

The upwelling driven by the Zhujiang River runoff in 2006 summer

作　　者：夏华永[1,2] 刘长建[2,3] 王东晓 Xia Huayong;Liu Changjian;Wang Dongxiao(South China Sea Marine Forecasting Center,State Oceanic Administration,Guangzhou 510300,China;Key Laboratory of Technology and Application for Safeguarding of Marine Rights and Interests,State Oceanic Administration,C-uangzhou 510300,China;South China Sea Marine Engineering Surveying Center,State Oceanic Administratiom,Guangzhou 510300,China;South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China)

机构地区：[1]国家海洋局南海预报中心,广东广州510300 [2]国家海洋局南海维权技术与应用重点实验室,广东广州510300 [3]国家海洋局南海调查技术中心,广东广州510300 [4]中国科学院南海海洋研究所,广东广州510301

出　　处：《海洋学报》2018年第7期43-54,共12页

基　　金：我国近海海洋综合调查与评价(908-01-ST07)

摘　　要：根据珠江口及其附近海域2006年夏季(7-8月)航次水文调查资料,发现调查期间,除了西南季风驱动下的冲淡水东向扩散外,粤西珠江口外冲淡水主要呈西向扩散趋势,并且西向扩散的冲淡水下存在上升流。已有的模型研究中,西南季风下珠江口外没有出现上升流,说明西南季风不是珠江口外上升流产生的主导因素。观测的温盐分布、潜标流速时间序列与走航ADCP流态表明,上升流产生的原因是:(1)口门外冲淡水南向扩展驱动了垂向重力环流;(2)密度跃层以下东北向沿岸流的底边界层Ekman效应;(3)口门外冲淡水团之间的气旋型中尺度涡旋作用。A summer hydrologic survey in the Zhujiang River Estuary and its adjacent seas was performed in July and August,2006.The survey data show that while a part of the diluted water from the Zhujiang River is transported eastwards by the overlying southwesterly monsoon,most of the diluted water is transported westwards off the coast of western Guangdong Province,and there is upwelling underlying the westwards spreading diluted water.In the existing modelling studies of the upwelling in the northern South China Sea,the upwelling does not occur off the Zhujiang River Estuary under the southwesterly monsoon,which demonstrates that the southwesterly monsoon should not be the major driving force of the upwelling off the Zhujiang River Estuary.As indicated by the distribution of sea water salinity and temperature,time series of currents from mooring observations and current fields from shipboard ADCP measurements,the major formation mechanism of upwelling ought to be：（1）the vertical gravitational circulations off the river mouth driven by the southwards spreading discharges;（2）the bottom boundary Ekman effect of the eastward coastal current beneath the density transition layer;and（3）the effect of mesoscale cool eddies among the diluted water bulges off the river mouths.

关 键 词：珠江口 冲淡水扩散 上升流 重力环流 

分 类 号：P731.21[天文地球—海洋科学]