中文关键词京津冀重污染PM_2.5垂直分布输送 英文关键词Jing-Jin-Ji Regionheavy pollutionPM_2.5vertical distributiontransport flux

作者	单位	E-mail
肖致美	天津市生态环境监测中心, 天津 300191	xiaozhimei01@163.com
徐虹	天津市生态环境监测中心, 天津 300191
李鹏	天津市生态环境监测中心, 天津 300191
唐邈	天津市生态环境监测中心, 天津 300191
陈魁	天津市生态环境监测中心, 天津 300191	kuichen@126.com
杨宁	天津市生态环境监测中心, 天津 300191
郑乃源	天津市生态环境监测中心, 天津 300191
杨文	中国环境科学研究院, 北京 100012
邓小文	天津市生态环境监测中心, 天津 300191	dxwpp@163.com

中文摘要 2016年12月17~19日重污染期间，在天津市武清区高村开展车载系留气球颗粒物浓度垂直观测，并以观测数据为基础，计算了区域内PM_2.5传输通量.结果表明重污染过程期间，大气混合层较低，约200 m左右，PM_2.5浓度垂直分布特征与混合层高度密切相关，混合层以下，PM_2.5浓度较高，垂直变化特征不显著，形成明显的污染层，混合层以上，PM_2.5浓度迅速降低并维持在降低水平.观测期间，粒径小于1.0 μm颗粒物浓度较高，粒径大于2.2 μm颗粒物浓度较低，近地层粒径为0.777 μm颗粒物浓度最高.颗粒物浓度粒径谱分布与相对湿度和混合层高度相关，高湿度和低混合层下颗粒物浓度粒径谱分布较宽泛.观测期间，PM_2.5在西南方向上的传输通量最高，占总传输通量的63.3%，其中46~156 m和156~296 m高度之间PM_2.5传输通量最高.近地面300 m内PM_2.5传输主要以西南方向传输为主，300 m以上传输方向较分散. 英文摘要 Based on vehicle-borne tethered balloon measurements, the vertical distribution of particulate matter (PM) concentrations were observed in Gaocun in the Wuqing District of Tianjin from December 17 to 19, 2016, during a period of heavy pollution. Using observational data, the transport flux of PM_2.5 in the Jing-Jin-Ji region was calculated. The results showed that the mixed layer was low at only 200 m during the heavy pollution period. The vertical distribution of PM_2.5 concentrations was closely associated with the heights of mixed layer whereby, below the mixed layer, PM_2.5 concentrations were higher. Vertical variation was insignificant, forming a district pollution layer. Above the mixed layer, PM_2.5 concentrations rapidly decreased and stabilized at low levels. During the observation period, higher concentrations of PM were found with particle sizes of less than 1.0 μm, and lower concentrations were observed for particle sizes larger than 2.2 μm. The size profiles of PM tallied with relative humidity and the height of the mixed layer. The size distribution was wider during periods of high humidity and with a lower mixed layer height. The greatest PM_2.5 transport flux was from the southwest, accounting for 63.3% of the total flux; the highest fluxes occurred at the heights of 46-156 m and 156-296 m. The dominant transport direction was southwest below 300 m, while the dominant transport direction was dispersed over 300 m.

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