近年来云南省PM2.5浓度变化趋势与潜在区域来源分析  

Analysis of the Change Trend and Potential Sources of PM2.5 Concentrations in Yunnan Province in Recent Years

作　　者：刘芮男 寇星霞 高怡[2] 赵靖川 张美根[2,5] LIU Ruinan;KOU Xingxia;GAO Yi;ZHAO Jingchuan;ZHANG Meigen(School of Earth Sciences,Yunnan University,Kunming 650504;State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029;Yueqing Meteorological Office,Yueqing,Zhejiang Province 325600;Institute of Urban Meteorology,China Meteorological Administration,Beijing 100089;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]云南大学地球科学学院,昆明650504 [2]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室,北京100029 [3]浙江省乐清市气象局,浙江乐清325600 [4]北京城市气象研究院,北京100089 [5]中国科学院大学,北京100049

出　　处：《气候与环境研究》2023年第5期509-517,共9页Climatic and Environmental Research

基　　金：国家自然科学基金项目41830109、42077203。

摘　　要：云南省地处低纬高原地区,毗邻东南亚,空气污染物质除受本地排放外也受东南亚地区跨境输送的影响。本文收集整理了2017~2021年云南省16个州市40个国控站观测数据,分析云南省污染特征和变化趋势;并利用后向轨迹(HYSPLIT)聚类分析和浓度权重轨迹(CWT)方法分析了PM2.5的主要区域来源。结果表明,云南省PM2.5年均浓度呈下降趋势,下降率为0.91±0.23μg m^(-3) a^(-1)。在季节变化上,春季浓度最高,全省平均为31.92±9.08μg m^(-3),夏季浓度最低,为13.50±2.69μg m^(-3)。春季东南亚地区生物质燃烧导致云南省PM2.5的污染最严重,最大贡献值超过40μg m^(-3),此外广西西南部也是云南省春季高潜在源区之一。在日变化上,PM2.5浓度呈现“双峰型”特征,最大值出现在09:00(北京时间,下同)至12:00和21:00至01:00,主要是人为活动与较低的边界层高度和风速等气象因素共同作用的结果。研究显示,云南省春季PM2.5浓度多源于跨境输送,这将为云南省空气污染物治理提供新的启示。Yunnan Province is located in a low-latitude plateau area adjacent to Southeast Asia.The local emissions and air quality of this province are affected by cross-border transportation from Southeast Asia.This study analyzes the observational PM2.5 concentration data from 2017 to 2021 at 40 sites in 16 cities of Yunnan Province to understand the characteristics and trends of PM2.5 pollution.Cluster analysis with the HYSPLIT(Hybrid Single-Particle Lagrangian Integrated Trajectory)backward trajectory model and concentration weighted trajectory are used to analyze potential PM2.5 sources.The results show that the annual mean PM2.5 concentration in Yunnan Province decreases by 0.91±0.23μg m^(-3) a^(-1).PM2.5 concentration varies seasonally,and its concentration reaches the highest value in spring with 31.92±9.08μg m^(-3) and lowest in summer with 13.50±2.69μg m^(-3).The PM2.5 pollution is severe in spring due to biomass burning in Southeast Asia,which contributes to<40μg m^(-3) of PM2.5 concentration.The high-potential source areas in spring include the southwest of Guangxi.The diurnal PM2.5 variations reveal a bimodal pattern with the value peaking between 0900 LST-1200 LST and 2100 LST-0100 LST,which is mainly attributed to human activities and meteorological factors,such as the lower boundary layer height and wind speed.In conclusion,PM2.5 during spring in Yunnan Province mostly comes from cross-border transportation.Thus,this study provides new insight for air pollutant control in the province.

关 键 词：云南省 PM2.5 跨境输送 潜在源区 

分 类 号：P401[天文地球—大气物理学与大气环境]