渤海及黄海北部的风海流数值计算及余流计算

A Numerical Computation of Wind-Induced Currents and Computation of Residual Currents in the Bohai Sea and the Northern Part of the Yellow Sea

依据黄渤海实测风的资料对渤海及北黄海进行了月平均风海流数值计算。计算表明 ,1月份在西北风的作用下 ,在渤海出现 1个逆时针旋转的环流 ,在辽东湾北部及黄海北部出现 1个顺时针旋转的环流 ,渤海海峡的海流北进南出。 7月份在南风和东南风的作用下 ,风海流的变化形式与 1月份大致相反 ,海峡处呈南进北出的形式。对渤海中部某点 1年的潮流资料通过低通滤波的方法计算逐时的余流值 ,得到该点 1年内表层最大的实测余流为 31.9cm/ s,全年 90 %多的时间内表层余流小于 10 cm/ s。对辽东湾北部某点和渤海湾西南部某点数月潮流资料也进行了低通滤波 ,并将得到的逐时余流与同步风作了比较。依据该 2点风和余流的关系以及黄海北部 6个点风和余流的关系验证了风海流数值计算的结果 。

Using the data of measured wind, the monthly average wind induced currents were numerically computed in the Bohai Sea and the northern part of the Yellow Sea. The numerical computation shows that, under the effect of the northwest wind in January, an anticlockwise rotative circulation occurs in the Bohai Sea and a clockwise rotative circulation occurs in the northern part of Liaodong Bay and of the Yellow Sea, meanwhile the wind induced currents are influent in the northern part of the Bohai strait and effluent in the southern part. It also shows that, under the influence of south and southeast winds in July, the types of wind induced currents are almost opposite to those in January, meanwhile the wind induced currents are effluent in the northern part of the Bohai strait and influent in the southern part. The hourly residual currents were computed using the low pass filter method and the tidal current data for one year at a station in the middle of the Bohai Sea. The computation shows that the maximum value is 31.9cm/s in a year in the surface water at this station and the values of the hourly residual currents are less than 10cm/s over 90% of the time. The hourly residual currents were also computed using the low pass filter method and the tidal current data for several months at two stations,one in the northern part of Liaodong Bay and the other in the southwestern part of Bohai Bay, and the results were compared with the measured synchronous winds. The results of wind induced current numerical computation agree well with measurements based on the relation between the winds and the residual currents at the two stations mentioned above and six stations in the northern part of the Yellow Sea.