2018年辽宁地区两次大雾天气成因分析  

Diagnoses of two foggy processes in Liaoning province in 2018

作　　者：阎琦[1] 李爽[1] 滕方达 吴芳妮 梁淑娥 张爱忠[4] YAN Qi;LI Shuang;TENG Fang-da;WU Fang-ni;LIANG Shu-e;ZHANG Ai-zhong(Liaoning Meteorological Observatory,Shenyang 110166,China;Shenyang Railway Experimental Middle School,Shenyang 110000,China;Liaoning Meteorological Service Center,Shenyang 110166,China;Meteorology Center,Northeast Civil Aviation Air Traffic Management Bureau,Shenyang 110169,China)

机构地区：[1]辽宁省气象台,辽宁沈阳110166 [2]沈阳铁路实验中学,辽宁沈阳110000 [3]辽宁省气象服务中心,辽宁沈阳110166 [4]民航东北地区空中交通管理局气象中心,辽宁沈阳110169

出　　处：《气象与环境学报》2020年第6期91-97,共7页Journal of Meteorology and Environment

基　　金：国家重点研发计划项目(2018YFC1507305);辽宁省气象局重点科研项目(201802);中国气象局预报员专项(CMAYBY2016-015和CMAYBY2019-024)共同资助。

摘　　要：应用能见度观测仪、风廓线雷达、加密自动站和常规气象观测等资料,从天气学角度对2018年1月17—18日和11月24—25日辽宁地区两次大雾天气特点及边界层热动力条件对大雾形成的影响进行分析。结果表明:两次大雾天气表现与成因较为类似。大雾发展均有两个阶段,且天气背景条件相似。其中大雾第一阶段主要为辐射雾,辽宁中部位于弱辐合带上,大雾出现在偏南气流中,偏南风将海上水汽输送到营口—沈阳一带,辐射降温配合弱的上升冷却作用,形成近地面逆温,同时温度露点差减小、相对湿度增大,导致大雾爆发性发展。大雾第二阶段,在次日07—08时冷平流入侵近地面层,逆温层再次建立导致大雾发展,低层弱冷平流到达地面时间和位置是大雾精细化预报的关键因素。Based on the data observed with visibility observers,wind profile radars,and from intensive automatic stations and conventional meteorological observations,the synoptic diagnosis of the two foggy weather processes and their responses to boundary layer thermodynamic conditions in Liaoning province in 2018 were investigated.The results show that the causes of the two heavy patches of fogs are quite similar.The fog experience two development phases under similar weather conditions.The first phase of the fog is radiation fog when the central part of Liaoning province lies in the weak convergence zone,the fog appears in the southerly wind area where the seawater vapor is transported to the Yingkou-Shenyang area.Then a weak ascending cooling cooperates with radiative cooling to form a near-surface temperature inversion.At the same time,the dew-point deficit decreases,and the relative humidity increases,leading to the explosive development of the fog.In the second development phase,the cold advection invades the near ground,causing the near-surface temperature to drop and forming inversion,and the fog develops again.So,the low-level cold advection intrusion is an important aspect that cannot be ignored in fog prediction,and its arrival time and location are the key influencing factors of fine fog prediction.

关 键 词：逆温 辐射雾 冷平流 

分 类 号：P458[天文地球—大气科学及气象学]