基于三维调和分离的同安湾口门断面冬季潮流和余流特征的分析

Analysis of tidal and residual current characteristics at the cross-section of Tong'an Bay entrance in winter based on the 3-D harmonic separation method

利用同安湾口门断面走航ADCP观测数据,采用基于高斯基函数的Candela空间插值方法,对海流进行空间三维的调和分离,并对分离的各分潮流与余流进行流场的回归检验分析,F(α=0.01)检验显示流场的回归效果显著.观测期间同安湾口门断面平均潮差为5.15 m,最小潮差4.38m,最大潮差5.98 m,断面上涨落潮最大流速分别为92.3、80.3 cm/s,潮流特征分析表明,同安湾口门断面的潮流运动形式为往复流,以半日潮流为主,约占70%潮流信息,潮流流速从海表面向海底递减.余流最大值为12.5 cm/s,空间分布上将同安湾口门断面一分为二形成北进南出的余流进出通道,这与以往余流格局的认识相符.

The Gaussian function-oriented Candela spatial interpolation was employed for a 3-D harmonic separation of the tidal and the residual currents from the ship-mounted ADCP data collected at the cross-section of Tong’an Bay entrance in winter,and the regression analysis of the separated tidal and residual currents field was also performed,which showed significant regression effect according to F（α=0.01） test.The average,minimum and the maximum tidal ranges at the cross-section of Tong’an Bay were 5.15,4.38 and 5.98 m,respectively;and the maximum flow velocity at the cross-section during flooding and ebb tides were 92.3 and 80.3 cm/s,respectively.According to the hydrodynamic analysis,the tidal form at the cross-section was rectilinear.And the tidal flow was dominated by semidiurnal current which represented 70% of the tidal information with the speed diminishing from the ocean surface to the bottom.The residual current had a maximum velocity of 12.5 cm/s,and the cross-section of Tong’an Bay entrance was divided by the spatial distribution of the residual current into a north-forward channel and a south-backward channel.Such a result was consistent with previous investigations.