不同分辨率下风场的数值模拟仿真研究

Numerical Simulation of Wind Field with Different Horizontal Resolution

文中利用新一代中小尺度数值预报模式WRF模式,针对发生在广州白云机场附近的一次风切变过程进行了数值模拟,模拟中采用四层嵌套的方式,在物理过程方案等参数完全一致的情况下,研究只有水平分辨率的不同对风场模拟效果造成的影响。实验中分别采用了9km、3km、1km和0.33km的水平分辨率,分别从水平风场和垂直风场两个角度对模拟效果的不同进行了对比分析,结果表明水平分辨率不同的模拟结果中风场的分布和变化趋势是一致的,但较高的分辨率对风场的模拟更加细致;当水平分辨率高于1km及其以上时,可以模拟出水平风场的细微变化;随着高度的增加,分辨率的不同对水平风场的模拟结果影响减小;水平分辨率的提高使模拟结果中垂直风场的变化更加剧烈,垂直气压场的变化幅度更大。

The new generation mesoscale and microscale numerical simulation system, weather research and forecast （WRF） model is used to simulate the wind field over the area of Guangzhou Baiyun airport on Ju121 2005 ,when it had windshear reported there. With the method of four domains nesting,the differences in the simulation result lead by the different horizontal resolutions are analyzed when the other parameters, such as the physics process parameters, are all the same. In the experiment, the horizontal resolutions 9km,3 km, 1 kin,0. 33km are tested, and the wind field is studied at the horizontal and vertical sections. Despite the difference of resolutions, the distribution of the wind speed and direction are similar. But it is described more exhaustive when the resolution is increased. The simulation result with more than 1 krn horizontal resolution could describe the particular changes in the horizontal wind field which could not be found in the 3 km and 9km resolution results. The vertical wind speed is appeared in some level when the resolution is more the 3km, with the isoclines of pressure changing more tempestuously.