摘要
为探究海陆风环流对沿海城市PM_(2.5)和O_(3)污染的影响特征,基于2016~2020年中国环境监测总站的污染物观测数据和同期气象资料以及ERA5气象再分析数据,分析了海陆风环流特征对天津市区域大气污染物PM_(2.5)和O_(3)浓度变化的影响.结果表明:2016~2020年天津共有海陆风日411d,6~9月出现最为频繁,12月频率最低.海陆风环流的季节特征差异造成了对PM_(2.5)和O_(3)的影响不同,冬季陆风环流会使PM_(2.5)在沿海区域积累,海风环流对沿海地区PM_(2.5)污染有稀释作用.夏季海陆风环流会改变沿海地区O_(3)分布情况,使O_(3)谷值更低且峰值更高,市区点、郊区点和沿海点O_(3)峰值浓度分别高于平均峰值4.1,8.9,16.0μg/m^(3),海陆风对峰值的影响程度随着站点与海岸线距离的增长逐渐减弱.2016~2020年间共有PM_(2.5)和O_(3)复合污染日94d,17次出现海陆风环流.海陆风型复合污染日中陆风环流将PM_(2.5)由中心城区传输至沿海,海风环流清洁海风对PM_(2.5)有清除作用.陆风环流时O_(3)光化学净消耗速率较高,海风环流时光化学净生成O_(3)时间更久,使O_(3)峰值出现时间延后,浓度提高.环流对O_(3)和PM_(2.5)的不同作用降低了PM_(2.5)和O_(3)复合污染的频率,海陆风对沿海地区污染物的输送和再分配使得区域污染成因更加复杂.
To investigate the impact of sea-land breezes on PM_(2.5)and O_(3)pollution in coastal cities,the observation pollution and meteorological data of China National Environmental Monitoring Centre and ERA5 hourly data from 2016 to 2020 were analyzed to elucidate the influence of sea-land breezes circulation characteristics on PM_(2.5)and O_(3)levels in the coastal areas of Tianjin.The results showed there were 411sea-l and breezes days between 2016 and 2020,the sea-land breezes circulation frequently occurred from April to September,with the lowest frequency in December.The variation in seasonal characteristics of sea-land breezes circulation led to different impacts on PM_(2.5)and O_(3)levels.Land breeze circulation leads to PM_(2.5)accumulation in coastal areas,and sea breeze circulation has a certain diffusion effect on PM_(2.5)in winter.Sea-land breezes circulation change the distribution of O_(3)in coastal areas,resulting in reduced valley values and increased daytime peaks of O_(3)The peak concentration of O_(3)in urban,suburban,and coastal locations were 4.1,8.9,16.0μg/m^(3)higher than the average peak value.The influence on peak value decreases as the distance from the coastline increases.A total of 94days of PM_(2.5)and O_(3)combined pollution from 2016 to 2020,and sea-land breezes occurred during 17 of these days.On PM_(2.5)and O_(3)combined pollution days with sea-land breezes,land breeze circulation transmitted PM_(2.5)from the central urban area to the coast,while the sea breeze exhibited a scavenging effect on PM_(2.5).The photochemical net decomposition rate of O_(3)during land breeze circulation was higher than those days without sea-land breezes,while the photochemical net generation time of O_(3)was longer during the sea breeze circulation.The effects of sea-land breezes circulation on O_(3)and PM_(2.5)reduced the frequency of PM_(2.5)and O_(3)composite pollution.Sea-land breezes'transport and redistribution of PM_(2.5)and O_(3)to coastal areas have a complex impact on regional pollution.
作者
许雅姿
杨亦成
刘永吉
孟鹏
孙乃秀
吴琳
毛洪钧
XU Ya-zi;YANG Yi-cheng;LIU Yong-ji;MENG Peng;SUN Nai-xiu;WU Lin;MAO Hong-jun(State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control,Tianjin Key Laboratory of Urban Transport Emission Research,College of Environmental Science and Engineering,Nankai University,Tianjin 300071,China;TEDA Ecology and Environment Bureau,Tianjin 300450)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2023年第10期5178-5187,共10页
China Environmental Science
基金
国家重点研发计划(2022YFC3703600,2022YFE0135000)
天津市科技支撑计划项目(20YFZCSN01000)。
