北京冬季重污染过程黑碳气溶胶的飞机观测

利用空中国王飞机平台搭载单颗粒黑碳光度计（SP2）针对北京2016年12月冬季一次污染过程进行了连续观测，阐述了污染发生、发展和消散过程中的黑碳（BC）气溶胶质量浓度、粒径分布和混合状态的变化特征.结果表明，此次污染过程是以PM_2.5污染为主的霾污染过程，最大值为432μg/m³.NO₂、SO₂和CO等气态污染物浓度经过3次污染积累阶段，为PM_2.5最终爆发增长提供了物质基础.静稳的大气条件为PM_2.5爆发增长提供了动力条件.污染发展过程中BC气溶胶先在地面累积增加，然后向高空传输；清除过程则是高空先被移除，低层缓慢降低.污染发展过程中北京地区黑碳气溶胶在边界层（PBL）浓度变化为先升高后减小，平均浓度为3.45μg/m³，质量中值直径（MMD）范围在190~220nm.随着污染过程的发展，气溶胶迅速老化，PBL内的BC老化比例在一天内可从27%增加到了51%，老化过程使得PM_2.5质量浓度爆发增长.污染过程中BC在边界层的垂直演变导致大气加热率发生变化，有利于逆温的维持和发展，加剧了污染物过程.

Aircraft observation of black carbon aerosols during heavy pollution in winter in Beijing

A single particle black carbon photometer (SP2) on the King Air platform was used to carry out continuous observation on a pollution process in the winter of December 2016 in Beijing, and the change characteristics of the mass concentration, particle size distribution and mixing state of black carbon aerosols during the occurrence, development and dissipation of pollution were elaborated in detail. The results showed that the pollution process was mainly haze pollution with PM_2.5 pollution, with a maximum of 432μg/m³. The concentration of gaseous pollutants such as NO₂, SO₂ and CO has gone through three stages of pollution accumulation, providing a material basis for the ultimate explosive growth of PM_2.5. The static and stable atmospheric conditions provide the dynamic conditions for the explosive growth of PM_2.5. In the process of pollution development, BC aerosols accumulate and increase on the ground first, and then are transmitted to the upper air; in the removal process, the upper air is removed first, and the lower layer slowly decreases. In the process of pollution development, the concentration of black carbon aerosol in Beijing area increased first and then decreased, with an average concentration of 3.45μg/m³, and MMD in the range of 190~220nm. With the development of the pollution process, aerosols are rapidly aging. The BC aging ratio in PBL can increase from 27% to 51% in one day. The aging process makes the PM_2.5 mass concentration explosively increase. The vertical evolution of BC in the boundary layer during the pollution process leads to atmospheric heating rate, which is conducive to the maintenance and development of temperature inversion and aggravates the pollutant process.