华北平原3次持续性大雾过程的特征及成因分析  

Characteristics of Three Sustained Dense Fog Events Across the North China Plain

作　　者：赵玉广 李江波 李青春[2] 

机构地区：[1]河北省气象台,石家庄050021 [2]北京城市气象研究所,北京100089

出　　处：《气象》2015年第4期427-437,共11页Meteorological Monthly

基　　金：国家自然科学基金项目(41175014);国家科技支撑计划项目(2014BAC16B04);河北省科学技术研究与发展计划项目(12277114D);北京市自然科学基金项目(8122022)共同资助

摘　　要：应用常规气象观测资料、区域自动站资料、NCEP/NCAR(1°×1°)再分析资料和L波段加密探空资料,对近年华北平原3次持续10 d以上的大雾天气过程的高空及地面气象要素条件、大尺度环流背景、边界层特征、温湿场特征以及形成原因和维持机理进行了天气学诊断分析。结果表明:3次大雾过程都发生在纬向环流背景下,其平均高度场、湿度场、温度场和海平面气压场极其相似,其高空和地面气象要素如相对湿度、风速、温度露点差、逆温层厚度等的统计值也比较近似;高空纬向环流长时间维持导致的冷空气活动偏弱,加上太行山、燕山对冷空气的阻挡和消弱造成的华北平原长期静稳天气形势,是华北平原大雾长时间维持的根本原因;纬向环流背景下多个"干性短波槽"活动、大尺度下沉运动、太行山地形造成的地形辐合线及偏西气流越过太行山下沉增温导致的层结更加稳定也是华北平原大雾加强和维持的重要原因。Based on conventional observation,the NCEP reanalysis data(1°×1°),regional automatic meteorological station,data and L-band sounding data,three persistent heavy fog events lasting over 10 days across the North China Plain in 2000 — 2013 are analyzed.The results show that all the three sustained dense fog events occur in the background of zonal circulation.The geopotential height field,humidity field,tempereture field and sea level pressure during the events are very similar.The surface weather conditions at the beginning of and during the dense fog events are also similar.The sustained dense fogs in the North China Plain are caused by the long-term static and stable synoptic pattern which is attributed to blocking function of Mountain Taihang and Mountain Yanshan to cold airs in the zonal circulation setting.Several upper short wave troughs mobiling to the North China Plain and large-scale sinking movement lead to the maintenance and enhancement of fog.Topographic convergence line caused by Mountain Taihang and moderately stable inversion which is formed by west current crossing Mountain Taihang also play an important role in the enhancement and maintain of the dense fog events.

关 键 词：华北平原 持续性大雾过程 边界层温湿特征 地形作用 干性短波槽 

分 类 号：P458.1[天文地球—大气科学及气象学]