廊坊市夏季大气气溶胶消光特性及其来源

通过对廊坊市2016年5~9月的空气污染指标进行连续观测，分析了PM_2.5污染特征、消光特性，并进行来源解析及潜在污染区域分析.观测期间PM_2.5浓度为（43.82±28.68）μg/m，PM_2.5中SO₄^2-，NO₃^-，NH₄⁺，OC和EC分别占PM_2.5总质量的24.74%，22.98%，20.54%，8.79%和5.50%，各组分随着PM_2.5浓度增加而增加；气溶胶散射系数（Bsp）和吸收系数（Bap）分别为（294.54±257.35），（16.05±9.14）Mm^-1，粗粒子（CM）对消光系数的贡献为11.12%，细颗粒子PM_2.5在大气消光中起主要作用，其中硝酸盐（32.23%），硫酸盐（27.28%）和OM （20.56%）为最主要消光成分；PM_2.5主要来自工业（14.14%）、机动车（15.15%）、二次无机气溶胶（38.38%）、燃煤（22.22%）及扬尘和生物质燃烧（10.10%），对消光系数的贡献分别为工业（1.32%）、机动车（17.25%）、二次气溶胶（55.57%）、燃煤（18.56%），扬尘和生物质燃烧（7.32%）.后轨迹分析表明廊坊市以来自山东、河南的小尺度_，短距离和来自内蒙古东北部、中部的中短距离传输为主，占比接近80%，污染源的潜在分布区域主要是山东东北部、河南东部、山西东部、辽宁西南等地.

Extinction characteristics of aerosol and the contribution of pollution source to light extinction in Langfang

The study by using the observation data (from May to September 2016) of Langfang Atmospheric Monitoring Super Station, the pollution characteristics of PM_2.5, extinction characteristics, source analysis and backward trajectory analysis were carried out. During the observation period, the concentrations of PM_2.5 were (43.82±28.68)µg/m³. SO₄^2-, NO₃^-, NH₄⁺, OC and EC accounting for 24.74%, 22.98%, 20.54%, 8.79% and 5.50% of the mass of PM_2.5, respectively. The concentration of components increased with increment of PM_2.5 concentration. Scattering coefficient (Bsp) and absorption coefficient (Bap) of atmospheric extinction were (294.54±257.35), (16.05±9.14)Mm^-1, respectively, The contribution of the coarse particles to the extinction coefficient (11.12%) was the lowest. PM_2.5 played a major role in atmospheric extinction. Among them, Nitrate (32.23%), Sulfate (27.28%) and OM (20.56%) were the most important extinction components. PM_2.5 mainly from industry (14.14%), motor vehicles (15.15%), secondary sources (38.38%), coal combustion (22.22%) and dust and biomass burning(10.10%). The contribution of various pollution sources to the extinction coefficient was 1.32% (industry), 17.25% (motor vehicle), 55.57% (secondary source), 18.56% (coal combustion) and 7.32% (dust and biomass burning). According to the backward analysis, the small-scale, short-distance transmissions from Shandong and Henan provinces as well as the medium and short-distance transmissions from northeastern and central Inner Mongolia were the major sources of the air mass of Langfang City, which were accounted for nearly 80%. The potential distribution areas of pollution sources were mainly in northeastern Shandong, eastern Henan, eastern Shanxi, and southwest Liaoning.