摘要
用三维陆架海模式(HAMSOM)对浙江近海的潮汐、潮流进行了数值模拟,并采用网格嵌套和动边界技术对原模式作了改进,以提高计算的精度,改进后的模式在浙江近海的应用中被证明是成功的.沿岸50个潮位站计算与实测值的比较表明,加入动边界以后的小区域细网格计算较之粗网格以及未加动边界以前精度普遍提高,比较的均方差结果为:M2分潮振幅差4 6cm,相角差7 14°;S2分潮振幅差5 0cm,相角差5 4°;K1分潮振幅差2 25cm,相角差5 76°;O1分潮振幅差1 56cm,相角差5 5°,可见计算与实测符合良好.另外,选取了105个实测潮流点,比较了表层M2和K1分潮流调和常数分量Ucosξ,Usinξ,Vcosη,Vsinη的实测值与计算值的偏差,结果表明计算与实测的符合程度较好.在此基础上,给出了各主要分潮的潮位同潮图、潮流同潮图、潮汐性质、潮流性质、潮流椭圆和潮流的运动形式等,发现4个主要分潮M2,S2,K1,O1在本区内均未出现无潮点;M2分潮流在29°18′N,122°46′E处有一个圆流点.此外还得到了一些有意义的结论,都与实测情况符合良好,从而对整个浙江沿海区域的潮汐潮流特性有了一个全面认识.
By means of three-dimensional baroclinic primitive equation model--Hamburg shelf ocean model (HAMSOM), the tide and tidal currents in the seas adjacent to Zhejiang are simulated. Furthermore, the original model is improved by two numerical technologies--nested grid and moving boundary method, which are introduced to increase the computational precision. The improved mode is proved to be successful while it is applied to the seas adjacent to Zhejiang. Comparing the computed values with those of 50 tidal observatories, it is found that the computational precision with fine grids and moving boundary is generally higher than that with coarse grids or fixed boundary. The root-mean-square values of comparative results show that the difference between the simulated and the observed amplitudes of M2 constituent is only 4.6 cm, the difference of phase-lags is 7.14°; the difference of amplitudes and phase-lags of S2 constituent are 5.0 cm and 5.4°; the difference of amplitudes and phase-lags of K1 constituent are 2.25 cm and 5.76°; the difference of amplitudes and phase-lags of O1 constituent are 1.56 cm and 5.5°. These indicate that the computational results agree with the observed ones very well. In addition, 105 current stations are chosen, and the difference between the calculated and the observed harmonic constant, Ucosξ,Usinξ,Vcosη,Vsinη of M2 and K1 component currents at surface layer is compared, and the results also show a good agreement. Based on these results, the co-amplitude and co-phase lag lines of the main component tides, the type of tide, tidal current ellipse, the type and the moving mode of tidal current are given. It is found that the four main constituents M2, S2, K1, O1 have no tide-free points in this area; and the M2 component current has one current-amphidromic point at 29°18′N, 122°46′E. In addition, some meaningful results are concluded, and agree with the observed ones well. Thereby, a thorough knowledge of the characteristics of tides and tidal currents is got in the whole coastal zone of Zhejiang Province.
出处
《海洋学报》
CAS
CSCD
北大核心
2003年第5期9-20,共12页
基金
浙江省自然科学基金资助项目(499018)
国家自然科学基金资助项目(40076010).
关键词
浙江近海
潮汐潮流
数值模拟
网格嵌套
numerical simulation
nested grid
moving boundary
tides and tidal currents
seas adjacent to Zhejiang
