摘要
无机气溶胶是天津冬季霾天出现的主要成分,研究挑选了2020年1月污染天中两个典型的高浓度无机气溶胶(SIA)过程(CASE1和CASE2),利用观测数据和耦合了在线污染物来源追踪方法的大气化学传输模式NAQPMS综合探究了气象要素、区域输送和化学过程的影响.两个过程的ρ(SIA)均值分别为76.8μg·m^(−3)和66.0μg·m^(−3),硝酸盐浓度高于硫酸盐和铵盐,均为硝酸盐为主导的污染过程.气象条件影响了无机气溶胶的生成,CASE1过程ρ(SIA)>80μg·m^(−3)对应的温度和相对湿度区间分别是[−6℃,0℃]、[2℃,4℃]和[50%,60%]、[80%,100%];CASE2过程对应的温度和相对湿度区间分别是[2℃,4℃]和[60%,70%].外来源对CASE1和CASE2过程SIA的平均贡献率为62.3%和22.1%,分别为区域传输主导和局地生成主导过程.CASE1本地排放对硝酸盐和硫酸盐的贡献分别为16.2μg·m^(−3)和8.2μg·m^(−3),均高于外来源的贡献(31.7μg·m^(−3)和8.8μg·m^(−3));CASE2过程本地排放对硝酸盐和硫酸盐的贡献分别为29.3μg·m^(−3)和25.1μg·m^(−3),而外来源的贡献为8.1μg·m^(−3)和9.4μg·m^(−3).这表明CASE1本地生成和外来源输送贡献造成硝酸盐高于硫酸盐浓度,而CASE2仅本地源造成硝酸盐浓度高于硫酸盐.两个污染过程气相氧化反应是无机气溶胶生成的首要来源,贡献率分别为48.9%和57.8%;非均相反应也是重要过程,对SIA的贡献率分别为48.1%和42.2%;液相反应的影响小.
Inorganic aerosol is the main component of haze days in winter over Tianjin.In this study,two typical high concentrations of secondary inorganic aerosol(SIA)processes,defined as CASE1 and CASE2,were selected during polluted days in January 2020 over Tianjin,and the effects of meteorological factors,regional transport,and chemical processes were comprehensively investigated combined with observations and numerical models(WRF-NAQPMS).The average SIA concentrations in CASE1 and CASE2 were 76.8μg·m^(−3) and 66.0μg·m^(−3),respectively,and the nitrate concentration was higher than that of sulfate and ammonium,which were typical nitrate-dominated pollution processes.Meteorological conditions played a role in inorganic aerosol formation.The temperature of approximately−6-0℃and 2-4℃and the relative humidity of 50%-60%and 80%-100%would be suitable conditions for the high SIA concentration(>80μg·m^(−3))in CASE1,whereas the temperature of approximately 2-4℃and the relative humidity of 60%-70%would be suitable in CASE2.The average contribution rates of external sources to SIA in the CASE1 and CASE2 processes were 62.3%and 22.1%,which were regional transport-dominant processes and local emission-dominant processes,respectively.The contribution of the local emission of CASE1 to nitrate and sulfate was 16.2μg·m^(−3) and 8.2μg·m^(−3),respectively,higher than that of external sources(31.7μg·m^(−3) and 8.8μg·m^(−3)).the local contribution of CASE2 to nitrate and sulfate was 29.3μg·m^(−3) and 25.1μg·m^(−3),respectively,whereas the contribution from external sources was 8.1μg·m^(−3) and 9.4μg·m^(−3),respectively.The quantitative result indicated that local formation and regional transport resulted in higher nitrate concentration than sulfate in CASE1,in contrast to only local sources in CASE2.The gas phase reaction was the main source of inorganic aerosol formation,contributing 48.9%and 57.8%in CASE1 and CASE2,respectively,whereas the heterogeneous reactions were also important proc
作者
卢苗苗
韩素芹
刘可欣
唐晓
孔磊
丁净
樊文雁
王自发
LU Miao-miao;HAN Su-qin;LIU Ke-xin;TANG Xiao;KONG Lei;DING Jing;FAN Wen-yan;WANG Zi-fa(Tianjin Environmental Meteorological Center,Tianjin 300074,China;Cooperative Laboratory for Atmospheric Environment-Health Research,China Meteorological Administration-Nankai University(CMA-NKU),Tianjin 300074,China;Tianjin Key Laboratory of Urban Transport Emission Research,College of Environmental Science and Engineering,Nankai University,Tianjin 300071,China;State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry(LAPC),Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;International Center for Climate and Environment Science,Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China;College of Earth and Planetary Sciences,University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2024年第5期2581-2595,共15页
Environmental Science
基金
国家自然科学基金项目(42130513)
中国气象局-南开大学大气环境与健康研究联合实验室开放基金项目(CMANKU202206)。
关键词
无机气溶胶
气象因素
区域传输
化学过程
天津
inorganic aerosol
meteorological parameters
regional transport
chemical process
Tianjin
