海浪状况及飞沫作用对台风强度和结构影响的数值模拟

A numerical simulation of ocean wave and sea spray's effect on typhoon intensity and structure

本文利用基于共享内存进程间通信方式耦合建立的WRF-WW3大气-海浪耦合模式,考虑Fairall和Andreas两种海洋飞沫通量参数化方案,对0604号台风"碧利斯"进行了数值模拟对比试验,分析了海浪状况和飞沫作用对台风路径、强度、动力和热力结构的影响.结果表明:海浪和飞沫对台风路径模拟影响不大.考虑海浪状况使海表粗糙度更接近于实况,能够改善对台风强度的模拟.不同的飞沫参数化方案对于台风强度模拟的影响不同,Fairall飞沫参数化方案使台风模拟强度增加,而Andreas方案则使之减弱.对于台风动力结构,考虑海浪状况使高风速区向气旋中心收缩且强度增大,导致10m风场与控制方案局地差值高达10m/s;飞沫作用则通过改变台风温湿场间接影响其动力结构.对于台风热力结构,考虑海浪状况有利于增强海表潜热、感热通量的传递,热通量与海面10m高风速区在分布和强度上都有更好的对应关系;在此基础上加入Fairall或Andreas飞沫参数化方案分别加强或削弱海表热通量传递;各方案潜热通量远大于感热,其大小是模拟台风强度不同的主要原因之一,海浪状况和飞沫作用主要通过影响潜热通量进而影响台风的强度变化.此外,尽管海浪状况和飞沫作用仅通过海表粗糙度和海表热通量影响台风,但其对台风动力结构和热力结构的作用可一直延伸至高空.

With the techni parameterization taken into consi and the third-generation ocean w effects of ocean wave and spray show that, ocean wave and spray of intensity simulation with n parameterizations have different deration, the coupled model of Weather Research and Forecasting （WRF） Model ave model WAVEWATCH Ⅲ was used to simulate the 0604 typhoon ＂Bilis＇. The on typhoon＇s track, intensity and structure are analyzed. The experiment results while Andreas weakens it. As to dynamic structure, ocean wave makes high wind region shrink towards typhoon center and also intensifies the wind, which makes the local difference of 10m-wind between coupled and controlled experiment greater than 10m/s; sea spray affects typhoon dynamic structure indirectly by changing the temperature and moisture field. As to the thermodynamic structure, after wave situation is considered, latent and sensitive heat flux between atmosphere and ocean increase and have a good correspondence with 10m wind upon the surface in both distribution and intensity~ on the basic of wave considered, introducing Fairall spray parameterization can enhance the upward heat flux on the surface, while Andreas parameterization weakens it~ latent heat flux is much greater than sensitive heat and makes main contribution to typhoon intensity~ sea wave and spray both have an great effect on typhoon intensity by affecting latent heat. Moreover, the effect of ocean wave and spray on dynamic and thermodynamic structure of typhoon can stretch to upper atmosphere, though they affect typhoon by roughness and heat flux on the surface.