Statistical analysis and parameterization of the hygroscopic growth of the sub-micrometer urban background aerosol in Beijing
Statistical analysis and parameterization of the hygroscopic growth of the sub-micrometer urban background aerosol in Beijing
复制标题
北京亚微米城市背景气溶胶吸湿增长的统计分析及参数化
DOI：
10.1016/j.atmosenv.2017.12.003
复制
发表时间：
2018-02
影响因子：
5
通讯作者：
Wiedensohler Alfred
中科院分区：
文献类型：
--
作者：
Wang Yu;Wu Zhijun;Ma Nan;Wu Yusheng;Zeng Limin;Zhao Chunsheng;Wiedensohler Alfred
气溶胶粒子的吸水率与粒子质量浓度、能见度下降和粒子化学有关，在华北平原重霾形成过程中起着重要作用。利用连续9个月的吸湿性-串联微分迁移率分析仪（TND）测量了北京城市背景大气中亚微米气溶胶颗粒（小于350 nm）的尺寸分辨吸湿生长因子（HGF）。对于直径为50 nm、75 nm、100 nm、150 nm、250 nm和350 nm的颗粒，在整个采样周期内取平均值得出的平均吸湿性参数（κ）值分别为0.14 ± 0.07、0.17 ± 0.05、0.18 ± 0.06、0.20 ± 0.07、0.21 ± 0.09、和0.23 ± 0.12，表明亚微米级城市气溶胶中有机物占主导地位。在春、夏、秋三季，随着粒径的增大，亲水性颗粒的数量分数增加，导致颗粒整体吸湿性随粒径的增大而增大。然而，总体平均κ值在75-150 nm范围内达到峰值，并且在冬季对于直径大于150 nm的颗粒物降低。冬季κ的这种粒径依赖性与采暖期燃煤产生的强烈的一次粒子排放有关。随着PM2. 5质量浓度的增加，新排放的煤烟等疏水性颗粒物的数量分数逐渐减少，表明老化颗粒物和内部混合颗粒物在严重的颗粒物污染中占主导地位。参数化方案的theHGF作为相对湿度（RH）和颗粒大小之间的50和350 nm的函数，确定不同的季节和污染水平。在20- 90%RH范围内，由参数化计算的HGF与实测HGF吻合较好。该参数化方法可用于确定北京地区（超细和细颗粒）和华北平原（细颗粒）大气气溶胶颗粒的吸湿增长。
The take-up of water of aerosol particles plays an important role in heavy haze formation over North China Plain, since it is related with particle mass concentration, visibility degradation, and particle chemistry. In the present study, we investigated the size-resolved hygroscopic growth factor (HGF) of sub-micrometer aerosol particles (smaller than 350 nm) on a basis of 9-month Hygroscopicity-Tandem Differential Mobility Analyzer measurement in the urban background atmosphere of Beijing. The mean hygroscopicity parameter (κ) values derived from averaging over the entire sampling period for particles of 50 nm, 75 nm, 100 nm, 150 nm, 250 nm, and 350 nm in diameters were 0.14 ± 0.07, 0.17 ± 0.05, 0.18 ± 0.06, 0.20 ± 0.07, 0.21 ± 0.09, and 0.23 ± 0.12, respectively, indicating the dominance of organics in the sub-micrometer urban aerosols. In the spring, summer, and autumn, the number fraction of hydrophilic particles increased with increasing particle size, resulting in an increasing trend of overall particle hygroscopicity with enhanced particle size. Differently, the overall mean κ values peaked in the range of 75–150 nm and decreased for particles larger than 150 nm in diameter during wintertime. Such size-dependency of κ in winter was related to the strong primary particle emissions from coal combustion during domestic heating period. The number fraction of hydrophobic particles such as freshly emitted soot decreased with increasing PM2.5mass concentration, indicating aged and internal mixed particles were dominant in the severe particulate matter pollution. Parameterization schemes of theHGFas a function of relative humidity (RH) and particle size between 50 and 350 nm were determined for different seasons and pollution levels. TheHGFs calculated from the parameterizations agree well with the measuredHGFs at 20–90% RH. The parameterizations can be applied to determine the hygroscopic growth of aerosol particles at ambient conditions for the area of Beijing (ultrafine and fine particles) and the North China plain (fine particles).
登录
查看更多内容
影响因子：
--
作者：
Zhijun Wu;Min Hu;Shang Liu;B. Wehner;S. Bauer;Andreas Ma ßling;A. Wiedensohler;T. Petäjä;
通讯作者：
Zhijun Wu;Min Hu;Shang Liu;B. Wehner;S. Bauer;Andreas Ma ßling;A. Wiedensohler;T. Petäjä;
上海冬季亚微米城市气溶胶的尺寸分辨吸湿性
影响因子：
5.5
作者：
Ye, Xingnan;Ma, Zhen;Hu, Dawei;Yang, Xin;Chen, Jianmin
通讯作者：
Chen, Jianmin
影响因子：
6.3
作者：
M. Ehn;T. Petäjä;H. Aufmhoff;P. Aalto;K. Hämeri;F. Arnold;A. Laaksonen;M. Kulmala
通讯作者：
M. Ehn;T. Petäjä;H. Aufmhoff;P. Aalto;K. Hämeri;F. Arnold;A. Laaksonen;M. Kulmala
影响因子：
64.8
作者：
Huang, Ru-Jin;Zhang, Yanlin;Prevot, Andre S. H.
通讯作者：
Prevot, Andre S. H.
影响因子：
4.5
作者：
K. Saarnio;A. Frey;J. Niemi;H. Timonen;T. Rönkkö;P. Karjalainen;Mika Vestenius;K. Teinilä;L. Pirjola;V. Niemelä;J. Keskinen;A. Häyrinen;R. Hillamo
通讯作者：
K. Saarnio;A. Frey;J. Niemi;H. Timonen;T. Rönkkö;P. Karjalainen;Mika Vestenius;K. Teinilä;L. Pirjola;V. Niemelä;J. Keskinen;A. Häyrinen;R. Hillamo