四川盆地天气型对大气复合污染的影响  

Impact of synoptic weather patterns on atmospheric compound pollution in the Sichuan Basin

作　　者：刘甚蓝 王艳[1] 徐婷婷 万超悦 彭卓豪 姜舒荞 LIU Shenlan;WANG Yan;XU Tingting;WAN Chaoyue;PENG Zhuohao;JIANG Shuqiao(College of Ecological Environment,Chengdu University of Technology,Chengdu 610059)

机构地区：[1]成都理工大学生态环境学院,成都610059

出　　处：《环境科学学报》2024年第1期86-101,共16页Acta Scientiae Circumstantiae

基　　金：四川省科技厅自然基金项目(No.2023NSFSC0746)。

摘　　要：利用ERA5再分析数据和污染物数据,根据T-PCA客观天气分型方法,研究了四川盆地2015—2020年天气分型及其对PM_(2.5)和臭氧污染的影响.天气分型包括西风槽前部型(SWP1)、西部低涡型(SWP2)、弱低压型(SWP3)、北部高压型(SWP4)、均压场型(SWP5)、东北高压型(SWP6)、中部高压型(SWP7)、东部高压型(SWP8)、底部高压型(SWP9).SWP1和SWP5多出现在春冬季,地面气象要素表现为低湿、较弱的东北风场,不利于污染物扩散,加上高压控制下的静稳天气使得光化学反应增强加速了O_(3)的生成.SWP1和SWP5共出现复合污染60 d;在高压天气型控制下SWP6和SWP7以及SWP8,地面风场较弱,温度较高,有利于O_(3)前体物的反应,SWP6型O_(3)污染最为严重,O_(3)浓度均值为125μg·m^(-3),超标率均值为23.87%;SWP7型下的O_(3)浓度均值为108μg·m^(-3),超标率均值为17.83%,SWP8型下的O_(3)浓度均值为121μg·m^(-3),超标率均值为20.98%.本研究还分析了成都市一次持续性复合污染过程,受SWP1和SWP5控制下,出现贴地逆温和多层逆温,抑制PM_(2.5)和臭氧的垂直扩散,明显的增温影响使得O_(3)污染积累.This study used ERA5 reanalysis data and pollutant data to investigate the weather patterns and its impact on PM_(2.5) and ozone pollution in the Sichuan Basin from 2015 to 2020 by using T-PCA objective weather classification method.The weather patterns included the western trough front type(SWP1),western vortex type(SWP2),weak low-pressure type(SWP3),northern high-pressure type(SWP4),uniform pressure field type(SWP5),northeastern high-pressure type(SWP6),central high-pressure type(SWP7),eastern high-pressure type(SWP8),and bottom high-pressure type(SWP9).The SWP1 and SWP5 weather patterns were more prevalent in spring and winter,surface meteorological elements exhibited low humidity and a relatively weak northeasterly wind field,which hindered the dispersion of pollutants.The stable weather conditions under high-pressure control enhanced photochemical reactions and accelerated the formation of O_(3).The compound pollution events occurred for a total of 60 days under the SWP1 and SWP5 weather patterns.Under the high-pressure weather patterns of SWP6,SWP7,and SWP8,the surface wind field was weak and the temperature was high,which favored the reaction of O_(3) precursors.Among them,the SWP6 weather pattern had the most severe O_(3) pollution,with an average concentration of 125μg·m^(-3) and an average exceedance rate of 23.87%.The average O_(3) concentrations in SWP7 and SWP8 were 108μg·m^(-3) and 121μg·m^(-3),respectively,with average exceedance rates of 17.83%and 20.98%.This study also analyzed a sustained compound pollution event in Chengdu,which was influenced by the SWP1 and SWP5 weather patterns,resulting in surface-based temperature inversion and multi-layer temperature inversion.These conditions inhibited the vertical diffusion of PM_(2.5) and ozone,and the significant warming effect contributed to the accumulation of O_(3) pollution.

关 键 词：天气型 四川盆地 PM_(2.5)和O_(3)复合污染 

分 类 号：X51[环境科学与工程—环境工程]