边界层参数化方案对台风“莫拉菲”热力和动力结构特征影响的对比

Comparison of the thermal and dynamic boundary layer structure with different boundary layer parameterizations during typhoon “Molave”

评估WRF模式对南海台风期间边界层的模拟能力,并对比分析了6组边界层参数化方案模拟的边界层热力和动力结构。与风温湿廓线探空资料的对比表明:边界层参数化对于位势高度和温度的模拟影响较小;Bou Lac参数化方案模拟的结果与实况变化趋势最接近,MYNN和YSU方案模拟的结果次之。是否考虑边界层参数化对热带气旋路径和强度的模拟影响显著;采用不同边界层参数化方案对热带气旋结构的模拟存在显著差别,且这种差异不限于边界层。和非局地参数化方案相对比,Boulac方案模拟的效果比较强,这可能是因为该方案有较高的混合效应、较大的对流动能以及能更好的模拟湿对流引起的湿度。Bou Lac方案模拟的结果更接近实际观测,这表明在稳定层结下使用局地k理论计算湍流扩散更为合理,但非局地方案在风速和气压的预报上存在一定优势。

Base on the mesoscale WRF mode, the performance of simulating the structural feature of the boundary layer in the South China Sea is evaluated and the thermal and dynamic structural feature in the boundary layer under 6 kinds of boundary layer parameterizations scheme are compared and analyzed. Compared with the sounding data, the results show that the simulation of geopotential height and temperature is not greatly affected with the different PBL scheme. The simulation with the BouLac scheme is closest to the observed data. The MYNN scheme and YSU scheme produce weaker result than that of the BouLac scheme. The PBL schemes on the simulation of tropical cyclone track and intensity have a significant different to the result without PBL schemes. The simulations of structure of tropical cyclone are significantly difference with different PBL schemes; the difference is not limited in PBL.