珠江三角洲地区一次辐射雾的数值模拟研究

NUMERICAL SIMULATION STUDY OF A RADIATION FOG IN PEARL RIVER DELTA REGIONS

本文利用美国国家大气研究中心 (NCAR)和宾夕法尼亚州立大学联合研制的第 5代中尺度气象模式系统MM5对珠江三角洲地区夏季出现的一次辐射雾过程进行了数值模拟研究。模拟的结果在辐射雾出现的时间以及辐射雾的高度方面都与实况十分相近。我们对辐射雾的形成机制也进行了分析和数值试验 ,结果表明 ,地面的长波辐射冷却促使辐射雾形成 ,而短波辐射的加热是辐射雾消散的主要原因。另外 ,增加模式的垂直分辨率以及改变珠江三角洲地区的下垫面类型都可以使模式模拟的辐射雾的结果有明显的改善。

In this paper, PSU/NCAR MM5 was utilized to simulate a radiation fog in summer in Pearl River Delta regions. The results showed that the simulation was successful, especially in simulating the formation and the height of the fog. We also analyzed the physical mechanisms of the formation of the fog and made some numerical experiments. The results showed that for the formation of the fog the most important factor was longwave radiative cooling. The fog dispersal was influenced most by shortwave radiation. In addition, the simulation results were obvious improved by increasing the vertical resolution or by modifying the landuse type in Pearl River Delta regions.