【摘要】 选取河北省唐山市2017年12月27～31日一次典型重污染过程,开展其污染特征及成因分析,对污染期间气象要素、大气颗粒物组分特征进行综合研究.结果表明,此次大气重污染过程中PM_2.5平均质量浓度为154μg/m³,重度污染及以上时PM_2.5/PM₁₀为0.7;PM_2.5中SNA质量浓度占比达58.0%,OC/EC的比值为4.1,说明颗粒物二次反应和有机物在此次污染过程有较大贡献;长期均压场以及近地面高湿、小风、逆温的出现导致唐山地区大气层结稳定,加之周边地区区域传输的贡献,是导致此次大气重污染过程的重要影响因素.更多还原

【Abstract】 Characteristics and formation mechanism of a heavy air pollution event during the period from December 27^th to 31^st, 2017 in Tangshan, Hebei, China were investigated. Combined with the mass concentration of particulate matter, gaseous pollutant concentrations, carbonaceous species and meteorological data, the component analysis of PM_2.5 was conducted in detail for this episode. The results showed that the average mass concentration of PM_2.5 during this period was 154μg/m³ exceeding the secondary standard of daily average concentration of the ambient air quality standard（GB3095-2012）. When the air pollution level was 5 and above, passed the level of heavy and above, the ratio of PM_2.5 over PM₁₀ became 0.7. The mass concentration of SNA accounted for 58.0% of PM_2.5, and the value of OC/EC was 4.1, which indicated that the secondary reaction of particulate matter and organic matter had a greater contribution in this pollution process. The local meteorological conditions, continuous uniform pressure field, the near-surface high humidity, light breeze and temperature inversion all played an important role in this heavy pollution event.Regional transmission was also an important contribsuting factor to this heavy pollution process.更多还原