济南市大气污染天气分型与冷空气对污染物的影响机制研究  

Influence Mechanisms and Weather Patterns of Air Pollution Episodes in Jinan

作　　者：江琪 桂海林 花丛 张碧辉 徐冉 何佳宝[3] 吕梦瑶 JIANG Qi;GUI Hailin;HUA Cong;ZHANG Bihui;XU Ran;HE Jiabao;LYU Mengyao(National Meteorological Centre,Beijing 100081;Key Laboratory of Transportation Meteorology,CMA/Nanjing Joint Institute for Atmospheric Sciences,Nanjing 210041;Environment Monitoring Centre of Ningbo,Ningbo 315012)

机构地区：[1]国家气象中心,北京100081 [2]南京气象科技创新研究院/中国气象局交通气象重点开放实验室,南京210041 [3]宁波市环境监测中心,宁波315012

出　　处：《气象》2022年第10期1281-1291,共11页Meteorological Monthly

基　　金：国家重点研发计划(2019YFC0214602);国家自然科学基金项目(41875181);中国气象局气象预报业务关键技术发展专项[YBGJXM(2019)02-02];国家气象中心预报员专项(CMAYBY2021-092);南京气象科技创新研究院北极阁基金项目(BJG202106);江苏省气象局北极阁开放研究基金项目(BJG201904)共同资助。

摘　　要：对济南市大气污染与气象要素以及高低空天气系统配置的相关关系进行研究,形成大气污染的天气学概念模型,并探讨不同强度冷空气过程对济南市大气污染物的生消作用。主要结论为:2016—2018年,济南市75%以上的PM_(2.5)污染日出现在地面均压场中。在天气类型出现概率均等的前提下,污染天气出现概率最高的地面天气类型为倒槽型(>55%),其次为均压场型(26.8%)。500 hPa为脊区控制型、平直西风带型、反气旋型、槽后型和槽前型时,均有>25%的概率出现PM_(2.5)污染。济南市PM_(2.5)污染概率最大(>50%)的高低空配置为地面倒槽配合高空槽后型,其次为倒槽配合平直西风带型以及均压场配合槽后型。平均情况下,PM_(2.5)污染时混合层高度低于1000 m,达到重度污染时小于800 m。污染时段相对湿度均值分布在65%±20%,温度均值为6℃±1℃。不同强度冷空气对污染物影响复杂,较强冷空气(ΔT_(24 h)>4.3℃,Δp_(24 h)>4.74 hPa)持续一定的时长(>3.5 m·s^(-1)的北风持续超过9.6 h),可将污染物彻底清除。强度稍弱的冷空气可能使污染改善,而较弱的冷空气(北风风速较小,但有一定的降温和升压体现)可能在传输作用下使得污染物浓度不降反增。In this paper,the correlation between air pollution and meteorological elements and the configuration of high-and low-altitude weather systems in Jinan City is discussed,a synoptic conceptual model of Jinan air pollution is formed,and the effects of cold air processes of different intensities on the generation and elimination of air pollutants in Jinan City are studied.The results show that during 2016-2018 more than 75%of PM_(2.5) pollution episodes in Jinan City occurred in the surface uniform pressure field.If the occurrence probability of each weather pattern was equal,the surface weather pattern with the highest occurrence probability of pollution episodes was the inverted trough pattern(>55%),followed by the uniform pressure field pattern(26.8%).Moreover,there was a more than 25%occurrence probability of PM_(2.5) pollution when the 500 hPa circulation was controlled by such weather systems,i.e.,the ridge,straight westerlies,anticyclone,behind the trough and in front of the trough.The circulation configuration at upper and lower levels with the greatest probability of PM_(2.5) pollution(>50%)in Jinan City was the type of the surface inverted trough and behind the upper-level trough,followed by the type of the surface inverted trough and the upper-level straight westerlies,and the type of the surface uniform pressure field and behind the upper-level trough.For the average,the mixed layer height was below 1000 m during PM_(2.5) pollution episodes and was less than 800 m under heavy pollution.During pollution periods,the average relative humidity is 65%±20%,and the average temperature was 6℃±1℃.The effect of cold air with different intensities on the pollutant episodes was complex.The stronger cold air(ΔT_(24 h)>4.3℃,Δp_(24 h)>4.74 hPa)with a certain duration,such as the northerly wind greater than 3.5 m·s^(-1) lasting more than 9.6 h,can remove pollutants completely.The slightly weaker cold air may be beneficial to reduce pollutant concentration.However,the weak cold air with a lower northerly wind

关 键 词：天气分型 高低空配置 大气污染 冷空气 

分 类 号：X16[环境科学与工程—环境科学] P445[天文地球—大气科学及气象学]