SWAN模式中风输入方案对南海台风浪后报的影响分析

Analysis of Impacts of Wind Input Scheme in SWAN Model on the Hindcast of Typhoon Waves in the South China Sea

基于近岸海浪模式(SWAN,Simulating waves nearshore),分别用ERA(ECMWF re-analysis)5、ERA-Interim、CCMP(Cross calibrated multi-platform)及美国国家环境预报中心(NCEP,National centers for environmental prediction)数据中心的天气预报再分析系统(CFSR,Climate forecast system reanalysis)的海表面10 m处风场作为不同的驱动风场,模拟15次经过南海的热带气旋过程产生的极值波高情况下的海浪,比较了不同风场驱动的海浪后报模拟值与Jason卫星高度计实测值的误差;再应用模拟精度最高的驱动风场,模拟同样条件的海浪场,对拖曳系数的参数化方案进行敏感性分析和比较。结果表明:在模式输入参数为默认值的情况下,ERA5风场与WU方案的风输入组合能够获得更加准确的中国南海热带气旋发生海域的有效波高;最后基于以上结果构建30年的南海海域海浪要素数据集,并使用Pearson-Ⅲ分布推算出南海海域的多年一遇有效波高。研究结果可以为南海海域的海浪灾害评估与海洋工程建设提供参考。

Wind fields 10 meters above the ocean surface from ERA(ECMWF Re-Analysis)5、ERA-Interim、CCMP(Cross Calibrated Multi-Platform)and CFSR(Climate Forecast System Reanalysis)from NCEP(National Centers for Environmental Prediction)were selected as the forcing wind to simulate the extreme value of significant wave height induced by 15 tropical cyclones passing over the South China Sea and compared the hindcast results of simulation from different forcing winds with values measured by Jason satellite altimeter in this paper.Conducted the sensitivity analysis and comparison of the drag coefficient schemes by simulating the extreme waves induced from surface wind with highest accuracy under the same conditions.The results showed that the wind input combination of ERA5 surface wind and WU schemes could get most accurate significant wave heights during the tropical cyclones passing over the area under the condition of default input parameters.Finally built a historical data set based on the results and gave the multiyear return period extreme values of significant wave height of South China Sea by using Pearson-Ⅲdistribution.