2014年初冬湖北省一次大雾成因分析和数值模拟

Cause Analysis and Numerical Simulation of Heavy Fog Event on 2014 Early Winter in Hubei

利用湖北省高速公路交通气象站观测数据及NCEP的1°×1°格点再分析资料,分析了2014年1月29-30日发生在湖北省内的大雾天气过程的气象要素变化特征及大雾形成机理,并利用优化参数化方案的数值模式对本次大雾过程进行了模拟。结果表明,大雾过程能见度基本与相对湿度变化趋势相反,气温与能见度变化趋势基本一致,风速都较之前有所下降。本次大雾是暖平流影响后,经夜间辐射冷却降温后形成,属平流辐射雾。利用WRF模式对本次大雾过程的模拟结果表明,除对海拔较高、受局地地形影响较大区域的模拟效果不理想外,模拟的大雾范围、强度、生消时间等与实况基本相符,可为以后大雾预报提供一定的参考。

Based on the observation data of expressway weather station in Hubei province and the reanalysis data( 1° × 1°) of NCEP,the meteorological elements variation characteristics and formation mechanism of the fog weather process occurred in Hubei province from January 29 to 30,2014 are analyzed. And the fog process is simulated using numerical model with optimized parameterization scheme.The results show that the visibility of the fog process is basically opposite to the change of relative humidity,the variation trend of temperature and visibility are basically the same,and the wind speed is lower than before. The fog is formed by night radiation cooling after the impact of warm advection,is an advection radiation fog. The WRF model simulation results of this fog process show that the simulated fog range,intensity,time of formation and vanishing and so on are basically in accordance with the actual situation,except for the areas with higher altitude and greatly local affected. And this can provide some reference for the future fog forecast.