摘要
利用中国国家地面站逐小时气象观测资料、中国环境监测总站空气质量逐时监测数据、ECMWF 0.125°(纬度)×0.125°(经度)再分析资料及青岛市八关山自动站常规要素逐小时数据,对2018年1月15~22日青岛市一次重度污染雾—霾天气过程的特征及其影响因子进行分析。结果表明:PM10为首要污染物,污染过程中青岛市48 h输入污染源前期主要为北方干冷气团与江淮湿空气在山东半岛北部汇聚堆积,后期则主要包括山东省内局地大气污染物排放。雾—霾期间,500 hPa中高纬地区受乌拉尔山阻塞高压和中西伯利亚冷低压控制,宽广的东亚横槽稳定维持,青岛上空以平直西风气流为主,地面等压线稀疏,风速小;随着横槽转竖,纬向型环流转为经向型,冷空气大举南下,风速急增,降雪发生,雾—霾迅速消散。在静稳的大气环流背景下,当近地逆温层内弱风或持续吹陆风,对流层低层上升和下沉运动较弱,水汽条件较好时,有利于雾—霾维持。综合分析雾—霾各阶段PM2.5浓度和相对湿度与能见度间的关系发现,霾阶段两因子影响力相当;雾阶段能见度主要受相对湿度的影响;静稳条件下PM2.5浓度累积增加是影响雾、霾混合阶段能见度的主要因子。
The pollutant trajectory,atmospheric circulation background,and meteorological factors of a heavy air pollution fog/haze event in Qingdao from 15 January to 22 January 2018,were analyzed using routine weather observation,air quality monitoring data,and ECMWF reanalysis data.The results indicate that during the early stages of pollution in Qingdao,the primary sources were the convergence and accumulation of dry and cold air from Mongolia and wet air from the Yangtze–Huaihe River basin.In the late stage,the major sources were the local air pollutants in Shandong Province,with PM10 being the primary pollutant.During the pollution process,controlled by the ural blocking high and cold low pressure in central Siberia,the East Asian transverse trough remained stable over the mid-high latitude area at 500 hPa.Over Qingdao,westerly airflow was dominant,with low wind speeds near the ground.As the transverse trough turned vertical,the zonal circulation changed to meridional,the cold air moved southward,the wind speed increased drastically,and the fog/haze dissipated rapidly.Under stable atmospheric circulation,when the surface layer had a weak wind or continuous land breeze,the ascending and descending motion of the air in the lower troposphere was weak,and the water vapor condition was favorable for the maintenance of fog/haze.Thus,by analyzing the relationship among relative humidity,PM2.5 concentration,and visibility at various stages of the process,it was observed that during the haze stage,the influence of both factors was comparable;moreover,during the fog stage,visibility was primarily affected by relative humidity,and accumulation and increase of PM2.5 concentration under static and steady conditions were the primary factors affecting visibility during the fog and haze mixing stage.
作者
樊晓婷
李英
刘应辰
FAN Xiaoting;LI Ying;LIU Yingchen(State Key Laboratory of Severe Weather,Chinese Academy of Meteorological Sciences,Beijing 100081;College of Oceanic and Atmospheric Sciences,Ocean University of China,Qingdao 266003)
出处
《气候与环境研究》
CSCD
北大核心
2022年第6期719-728,共10页
Climatic and Environmental Research
基金
国家自然科学基金项目51778617
中国气象科学研究院科技发展基金项目2020KJ019。
关键词
雾—霾
后向轨迹
环流形势
气象因子
Fog/haze
Backward trajectory
Circulation
Meteorological factor