风对北部湾入海径流扩散影响的研究

Wind Effects on Spread of Runoffs in Beibu Bay

关键词:  北部湾  红河  径流  环流

Key words:  Beibu Gulf  Red River  runoffs  current circulation

摘要:

本文根据北部湾红河等入海径流的最新资料,使用FVCOM数值模式计算风场显著不同的1988年和1989年夏季径流扩散特征;使用冬季平均风场计算包括径流在内的冬季北部湾环流。得出如下结论:(1)1988年8月,强的西南风除了在北部湾西岸产生较强的北向沿岸流外,东部涠洲岛附近形成气旋式环流;相应地在北部湾中偏北部有一个弱的反气旋涡,中部出现较大的气旋式环流;(2)1989年8月的西南风非常弱,表层的红河冲淡水主要沿北部湾西岸向南流,来自琼州海峡的余流,在北部湾北部形成范围较大的气旋式环流,与此同时,海湾南部也出现一个较强的气旋式环流;(3)冬季,在冬季偏北风驱动下,北部湾基本是气旋式环流,只有西北部水域出现一个反气旋式环流。

Abstract:

By using the FVCOM numerical model and the latest runoff data of the Red River in the Beibu Gulf,diffusion characteristics of the runoffs were simulated in the summer of 1988 and 1989,since there were apparent difference in wind distribution in summer in these two years.Furthermore,the current circulation of Beibu Gulf in winter was simulated with the mean wind field in winter and the runoffs.The conclusions are as follows:(1) In August 1988,the strong southwest wind formed a strong northern coastal current in the west bank of the Beibu Gulf,and a cyclonic circulation near the Weizhou Island in the east.Accordingly,there were a weak anti-cyclonic circulation in the north of the Beibu Gulf and a larger cyclonic circulation in the middle.(2) In August 1989,the southwesterly wind was weaker than in August 1988,and the surface runoffs of the Red River went mainly to the south along the west bank of the Beibu Gulf.The residual current from the Qiongzhou Strait formed a large cyclonic circulation in the northern area of the Beibu Gulf.At the same time,there was a strong cyclonic circulation in the southern area of the Beibu Gulf.(3) In the winter,the Beibu Gulf reveals mainly cyclonic circulation driven by strong northerly wind in winter.An anti-cyclonic circulation appears only in the northwest waters of Beibu Gulf.