北京一次持续性雾霾的特征及成因分析  

Characteristics of persistent fog and haze process and its forming reason in Beijing

作　　者：赵娜[1] 尹志聪[1] 吴方[1] 

机构地区：[1]北京市气象局,北京100089

出　　处：《气象与环境学报》2014年第5期15-20,共6页Journal of Meteorology and Environment

基　　金：公益性行业(气象)科研专项"大城市多源气象信息集成管理与综合应用技术"(GYHY201206031);中央级公益性科研院所基本科研业务费专项基金项目"不同天气形势下北京对污染物排放的容纳度和清除能力评估"(IUMKY201314PP0404)共同资助

摘　　要：基于2013年1月9—15日北京地区一次持续雾霾过程,对环流形势、气象要素、物理量场及污染监测情况进行分析。结果表明:高浓度PM2.5和SO2事件持续时间超过100 h,浓度达到严重污染级别。高空为偏西或西南气流且850 h Pa有弱暖平流输送和地面倒槽维持少动是有利于雾霾持续的背景条件。持续轻雾或霾对湿层厚度要求不高,在925 h Pa以下即可,且湿层越厚,能见度越低。逆温维持是雾霾持续的主要原因,且轻雾或霾为主时逆温层特点为厚度浅强度弱,逆温高度或强度突然增大可预示轻雾霾向大雾或雪转换;850 h Pa以下涡度平流较弱是轻雾或霾持续的动力结构;总温度平流垂直分布表现为闭合中心强度在500 h Pa明显分界,且相对较弱的平流中心高度一般在850—1000 h Pa之间,当高度达到500 h Pa时可预示雾霾天气消散。Based on meteorological and pollutional data,a persistent fog and haze process in Beijing on January 9 to 15,2013 were diagnosed,and the circulation,meteorological elements,physical quantity field and pollution mo-nitoring status were analyzed.The results indicate that the persistent duration of high PM2.5 and SO2 concentrations events exceeds 100 hours,and their concentrations reach a severe pollution level.There are westerly or southwest air flow at upper level,weak warm advection at 850 hPa and inverted trough on surface.They supply favorable background for the persistent fog and haze process.The continuous light fog and haze do not need thicker wet layer and the thickness of wet layer occurring below 925 hPa is sufficient.The thicker wet layer is,the lower visibility is.Maintenance of temperature inversion layer is a main reason for persistent fog and haze.Temperature inversion layer is thin and weak when there is light fog or haze,and its thickness or intensity enlargement is indicative to transition to heavy fog or snow.Weak vorticity advection below 850 hPa is the dynamic condition of persistent light fog or haze.There is a significant dividing line of total temperature advection on 500 hPa,and the height of weaker advection centre is always between 850 hPa and 1000 hPa.The light fog and haze will dissipate when the height of centre reaches 500 hPa.

关 键 词：雾霾 污染 环流形势 平流 

分 类 号：X513[环境科学与工程—环境工程]