Numerical Simulation Of Tide And Tidal Current In The Bo Sea And Yellow Sea Based On The FVCOM

Tidal propagation, basically formed by tide and current, is the basic motion of sea water, which influence the research of many Physical Oceanography problems. Tidal propagation play a dominant part in the nearshore area. As a result, study on tide and current has important significance to the development of Physical Oceanography and national production.Hydrodynamic field of the Yellow Sea and Bo Sea are simulated based on the FVCOM. The hydrodynamic model are established by adopted unstructured mesh, bottom friction, vertical mixing and non-linear. The horizontal resolution transforms from 5000 meters near the open boundary to 1000 meters near the coast and islands gradually. There are 5 sigma layers in the vertical direction. The open boundary nudging are sea level predicted from the ChinaTide. The bottom friction are described using the bottom drag coefficient varied spatially. Compared to the measured harmonic constants at 37 gauge stations, the mean deviation of tidal constituent’s amplitude is 5.0cm, 4.9cm, 3.0cm, 2.0cm respectively, while the phases is 9.9°, 10.8°, 22.5°, 5.2°.The relativity of amplitude(R2) is 0.99187, 0.97359, 0.91304, 0.86013, and the counterpart is 0.9938, 0.98592, 0.99781, 0.99619 respectively. The current is verified using current data of four different periods. It was side that the precision of simulated results agree and correspond well with the in-situ observations, so the hydrodynamic model could be a foundation for the future research.According to the results by the quasi harmonic analysis, the co-tidal chart, the current ellipse, Euler residual chart and the distribution chart of tidal current property are drew. It is shown that the tide in research sea area is mainly Semidiurnal tide, while the Diurnal tide is located at Qinhuangdao offshore, Haizhouwan offshore and coastal old Yellow River delta. The current is mainly Semidiurnal current, and the Diurnal current is located at southeast part of Bohai strait. What’s more, the coastal current is reciprocal flow, while the offshore region is rotational flow. The residual in the surface layer can reach up to 20cm/s, which appear at the island group near Zhangzidao, Laotieshan waterway, Liaodong bay, Tianjin port and western sea of Korean Peninsula. The Euler residual offshore is small, merely to 2cm/s~3cm/s. The middle and bottom layer are similar to the surface layer. There are three amphidromic points of Semidiurnal tide, one amphidromic point of diurnal tide, while the current amphidromic points is four and four respectively. The position agree with the predecessors’ achievements. According to the paper, we can have a more comprehensive understanding of the tidal current characteristics in the Yellow Sea and Bo Sea.