对一次温带气旋引发的渤海风暴潮过程的数值模拟

利用三维非静力中尺度大气模式—MM5（Version 3.7）输出的黄渤海海面风场和气压场预报资料，用三维斜压陆架海模式—HAMSOM对2008年8月22日温带气旋造成的渤海风暴潮过程进行了模拟，得到逐时的渤海增水场、渤海风暴潮流场，与验潮站的观测数据进行比较。结果表明：在渤海西部已经转西北风的情况下，塘沽出现了121 cm的高增水，造成这种现象的原因很复杂，其中远距离的气旋作用产生的北黄海海域偏东大风导致北黄海水体大量涌入渤海应该是一个主要原因。这也是今后预报业务中必须特别关注的产生风暴潮的重要因素。数值模拟的塘沽测站的风暴潮增水极值及增水过程都和实测值符合较好，本次过程中数值预报能够很好地模拟出这种特殊的风暴潮。在离岸风的情况下产生风暴潮，这仅靠预报员凭经验主观分析判断是很难的，数值预报可以弥补预报员主观分析的不足。

Numerical simulation on storm surge caused by extratropical cyclone in Bohai Sea,China

Based on three-dimensional nonhydrostatic mesoscale atmospheric model-MM5 (Version 3.7) and Hamburg shelf ocean model (HAMSOM), the storm surge in Bohai Sea on August 22, 2008 caused by the extratropical cyclone was simulated. The forecasting fields of meteorological elements such as wind and pressure fields related to storm surge were acquired, then input them to HAMSOM and simulate storm surge in the Bohai Sea. Finally, hourly water elevation field and storm surge current field were analyzed and compared with the observational data in Tanggu station. The results indicate that when the wind direction transfers into the northwest in the western Bohai Sea, water elevation reaches 121 cm at Tanggu station. The easterly wind in the North Yellow Sea caused by long distance cyclone makes a lot of water of the North Yellow Sea flowing into the Bohai Sea, which is one of the main reasons causing the above high water elevation. This is also an important element forming storm surge, and it should be particularly concerned about storm surge forecast in future. Simulation values on extreme water elevation of storm surge and its process agree well with the observation values at Tanggu station. This particular storm surge is simulated by the numerical prediction model very well. It is difficult to judge for forecaster relying on the subjective experience if storm surge is generated in the case of offshore wind, while numerical prediction model can make up the lack of subjective analysis.