贵州一次典型锋面大雾的成因分析  

A Typical Frontal Heavy Fog in Guizhou: Cause Analysis

作　　者：吉廷艳 牛迪宇 秦杰 夏晓玲 裴兴云 Ji Tingyan;Niu Diyu;Qin Jie;Xia Xiaoling;Pei Xingyun(Guizhou Meteorological Service Center,Guiyang 550002;Wudang District Meteorological Office of Guiyang,Guiyang 550018)

机构地区：[1]贵州省气象服务中心,贵阳550002 [2]贵阳市乌当区气象局,贵阳550018

出　　处：《中国农学通报》2020年第15期87-93,共7页Chinese Agricultural Science Bulletin

基　　金：贵州省科技支撑计划项目“高速公路大雾预报预警技术研究”(黔科合支撑[2017]2812);中国气象局预报员专项“贵州秋冬季典型低能见度过程特征及客观预报性能分析”(CMAYBY2017-067)。

摘　　要：为了进一步提高锋面大雾预报水平,利用天气图资料和自动站逐小时观测资料,分析了2017年1月3-4日发生在贵州的一次持续性大范围锋面大雾天气成因。结果表明:偏南气流将孟加拉湾和南海水汽向贵州等地输送,850 hPa温度槽携带冷平流入侵及地面静止锋形成,为这次锋面大雾提供了有利天气条件。水汽在贵州上空持续辐合导致低云发展增厚,云底下降接地形成地面大雾;静止锋东退北抬,西南暖湿气流经过冷平流区域致使大雾持续发展;逆温层逐渐减弱消失、云底抬升,大雾也随之减弱消散;低层气流辐合上升、中层气流辐散下沉有利于大雾形成。大雾期间水汽饱和、风速较小,前期气温呈下降趋势,中后期近地层处于较稳定状态,有利于大雾形成和维持。To further improve the forecast level of frontal fog, we analyzed the causes of a persistent large-scale frontal fog occurred in Guizhou from January 3-4, 2017 by using synoptic map data and hourly observation data from automatic stations. The results showed that: the southerly airflow transported vapor from the Bay of Bengal and the south China Sea to Guizhou and other places;the 850 hPa temperature trough carried cold advection invasion and the formation of ground stationary front, which provided favorable weather conditions for this frontal fog;the continuous convergence of water vapor over Guizhou resulted in the development and thickening of low clouds, the formation of heavy fog on the ground was due to the descent and grounding of cloud bottom;the stationary front retreated to the east and moved northward, the warm and wet air flow in the southwest passed through the cold advection region, which caused the fog to continue to develop;the inversion layer gradually weakened and disappeared, the cloud floor rose, the fog also weakened and dissipated;the convergence of low-level airflow and the divergence of middle level airflow were beneficial to the formation of fog. During the fog period, the water vapor saturation and wind speed were small, and the temperature in the early stage was decreasing and kept stable in the middle and late stages near surface layer, which was conducive to the formation and maintenance of the fog.

关 键 词：锋面大雾 天气成因 静止锋 逆温层 暖湿气流 

分 类 号：P458.3[天文地球—大气科学及气象学]