2006年夏季琼东、粤西沿岸上升流研究

利用2006年夏季广东、海南、广西近海的海洋水文调查资料和卫星遥感QuikSCAT风场资料分析琼东、粤西沿岸上升流的空间结构特征, 探讨风场、风应力旋度对上升流的影响以及上升流区水温、海流、海平面对上升流的响应。结果表明:琼东、粤西沿岸上升流区并非相互独立, 从10 m层以下已经连成一片。琼东沿岸上升流主要由夏季西南季风驱动而产生, 风应力旋度也有一定贡献。琼东沿岸上升流的强度比粤西强。琼东沿岸海域的上层海水(18 m以浅)以离岸运动为主, 中下层海水以向岸运动为主。上层的离岸流速大于中下层的向岸流速。琼东沿岸的上升流现象是间歇性的, 与沿岸风速强弱有关。琼东沿岸海域海平面的升降与上升流的强弱有良好的关系, 上升流的强弱滞后于海平面的升降约1～2 d。

Study on coastal upwelling in eastern Hainan Island and western Guangdong in summer, 2006

In this paper, the hydrographic survey data in coastal waters of Guangdong, Hainan, and Guangxi during the summer of 2006, combined with QuikSCAT wind data were used to document spatial characteristics of upwelling, and to explore roles of the wind and wind stress curl on the upwelling, and responses of temperature, currents, sea level to the upwelling. The results show that the coastal upwelling regions in eastern Hainan and western Guangdong are not separated but merged together below 10 m layer. The coastal upwelling in eastern Hainan is mainly driven by the southwest monsoon during summer, and the wind stress curl also impacts the process of upwelling. The coastal upwelling in western Guangdong is mainly caused by the local wind stress curl. The intensity of upwelling in eastern Hainan coast was stronger than that in western Guangdong coast. In eastern Hainan coast, the water in upper layer (<18 m) moved primarily offshore, while the water in lower layer moved dominantly onshore, with a stronger flow in upper layer. The upwelling phenomenon in eastern Hainan is intermittent, and modulated by the strength of alongshore wind. The strength of coastal upwelling in eastern Hainan was closely correlated to local sea surface height, with variations of former lag that of later in 1-2 days.