溧水河乌刹桥段一次雨雾的数值模拟研究

A numerical simulation study of rain fog at Lishui River Wucha Bridge reach

应用WRF数值天气预报模式对溧水河乌刹桥段一次雨雾进行数值模拟,模拟时间为北京时间2007年12月05日20∶00至2007年12月06日20∶00,采用4层嵌套结构,最内层水平分辨率为1 km×1 km。模拟并分析了溧水河乌刹桥段的第二层嵌套范围的海平面气压场、风场、液态水含量、相对湿度等分布情况,并将溧水河乌刹桥位置的10m风速模拟值和能见度计算值分别与气象站实测值进行了对比分析。研究结果表明,应用WRF数值天气预报模式对这次溧水河乌刹桥段雨雾的风场、相对湿度、能见度等模拟效果较好,此次溧水河乌刹桥段雨雾的成因为处于低压槽及均压区,有利于水汽聚集,水汽易达到饱和;相对湿度大,在85%以上;微风,风速为2-4 m/s,有利于雾天气形成和维持。

The WRF numerical weather forecast model is used to simulate the rain fog of the Lishui River Wucha bridge section.The simulation time is from 20:00 on December 05,2007 to 20:00 on December 06,2007 at Beijing time.The simulation used 4-layer nested structures;the innermost layer has a resolution of 1 km×1 km.The distribution of sea level pressure field,wind field,liquid water content and relative humidity are simulated and analyzed in the second layer nesting range of Lishui River Wucha bridge section,and the simulation values of the 10m wind speed and the visibility value of the location of the Lishui River Wucha bridge are compared and analyzed with the measured values of the meteorological stations.The results show that the WRF model can simulate the wind field,relative humidity and visibility of the rain fog in Lishui River Wucha bridge section well.The rain fog in the Lishui River Wucha bridge section is in the low pressure trough and equalizing pressure zone,which is beneficial to the water vapor accumulation,and the water vapor is easy to reach saturation.The relative humidity is quite high,above 85%,and the wind speed is 2-4m/s,which is conducive to the formation and maintenance of this foggy weather.