广西近岸西部海域的海流特征研究

Characteristics Researches of Current Nearby the West of Guangxi Offshore

利用广西近岸西部白龙半岛海域2011—2012年连续一年的观测资料和数值计算方法,研究了该海域潮流和余流的基本特征及变化规律,得出如下结论:白龙半岛海域潮汐为正规全日潮,但是潮流为不规则半日潮流;旋转谱分析显示,潮流逆时针旋转分量强于顺时针旋转分量,全日潮流的总能量小于半日潮流的能量;潮流振幅在夏季明显高于冬季,这是因为夏季北部湾北部的显著层结导致的较浅海域的内潮同样比较显著,并且表现为由表层向底层加强;另外,本文首次发现,经过北部湾的台风会增强主要的全日、半日分潮的能量,引起潮流的流速增加。通过数模试验,第一次发现在白龙半岛附近海域存在一个小尺度的反气旋涡,范围大约位于108°E^108.7°E、20.8°N^21.5°N,涡旋在秋季产生,可以一直持续到冬季结束。

In this paper, one consecutive year＇s observed data from 2011 to 2012 nearby Bailong Peninsula and numerical simulation model were used to analyze the characteristics of tide, tidal current and subtidal current in the northern Tokin Gulf. Conclusions are as follows ： the sea nearby Bailong Peninsula owns regular diurnal tide and irregular semidiurnal tidal current. The results of rotary spectrum showed that the CCW（counterclockwise） components is bigger than CW（clockwise）, and the energy of diurnal tidal current is smaller than the semidiurnal. The amplitudes of tidal current of total layers in summer arebigger than in winter, because the inertial tide caused by stratification in summeris significantin shallow water, and the deeper water depth is, the stronger inertial tide is. In addition,we firstly find that typhoon passing through Tokin Gulf will strengthen the semidiurnal and diurnal tidal current energy with increasing of current velocities. The results of numerical simulation model firstly show that an anti-cyclone eddy exists nearby Bailong Peninsula, which locates within range from 108°E to 108. 7°E east longitudeand from 20.8°N to 21.5°N north latitude,and it generates in autumn, and disappears at the end of winter.