基于“山竹”台风的波浪数值模拟

Numerical simulation of wave based on Typhoon Mangkhut

研究台风风场结构中Holland B参数对台风浪模拟结果的影响。采用ERA-5背景风场与Holland经验风场叠加构成的台风输入风场,利用MIKE21 SW波浪数学模型进行南海大范围台风浪数值模拟;结合1822号“山竹”台风期间的实测风浪数据,研究Holland B参数对台风风场构造的影响机理,对四种常用Holland B参数计算公式的各个模拟值进行验证,并对其进行对比分析。结果表明:四个Holland B参数公式计算得到的风速和有效波高模拟值均与实测值有较好一致性,B1参数公式的计算结果与实测值吻合最好;不同Holland B参数对风向和平均波向基本不产生影响,其模型模拟值与实测值吻合度较高;通过台风场与波浪场的空间分布对比分析,为沿海地区台风期间防灾减灾提供参考建议。

The influence of Holland B parameter in typhoon wind field structure on typhoon wave simulation results is studied.The input wind field of typhoon is composed of ERA-5 background wind field and Holland experience wind field,large scale typhoon waves in the South China Sea are simulated by Mike21 SW wave mathematical model;Combined with the wind and wave data of Typhoon Mangkhut of No.1822,study on the influence mechanism of Holland B parameter on the structure of typhoon wind field,the simulation values of four commonly used Holland B parameter calculation formulas are verified and compared.The results showed that:simulated values of wind speed and significant wave height calculated by four Holland B parameter formulas are in good agreement with the measured values.The calculation results of B1 parameter formula are in best agreement with the measured values;Different Holland B parameters have little effect on wind direction and average wave direction,the simulation value of the model is also in good agreement with the measured value.Through the comparative analysis of the spatial distribution of typhoon field and wave field,it can provide suggestions for disaster prevention and mitigation during typhoon in coastal areas.