<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Yu Wang</style></author><author><style face="normal" font="default" size="100%">Zhijun Wu</style></author><author><style face="normal" font="default" size="100%">Nan Ma</style></author><author><style face="normal" font="default" size="100%">Yusheng Wu</style></author><author><style face="normal" font="default" size="100%">Limin Zeng</style></author><author><style face="normal" font="default" size="100%">Chunsheng Zhao</style></author><author><style face="normal" font="default" size="100%">Alfred Wiedensohler</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Statistical analysis and parameterization of the hygroscopic growth of the sub-micrometer urban background aerosol in Beijing</style></title><secondary-title><style face="normal" font="default" size="100%">ATMOSPHERIC ENVIRONMENT</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">air pollution</style></keyword><keyword><style  face="normal" font="default" size="100%">HTDMA</style></keyword><keyword><style  face="normal" font="default" size="100%">particle hygroscopicity</style></keyword><keyword><style  face="normal" font="default" size="100%">Urban aerosol</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">FEB</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">PERGAMON-ELSEVIER SCIENCE LTD</style></publisher><pub-location><style face="normal" font="default" size="100%">THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND</style></pub-location><volume><style face="normal" font="default" size="100%">175</style></volume><pages><style face="normal" font="default" size="100%">184-191</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">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 (kappa) 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 it values peaked in the range of 75-150 nm and decreased for particles larger than 150 rim in diameter during wintertime. Such size-dependency of kappa 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 PM2.5 mass concentration, indicating aged and internal mixed particles were dominant in the severe particulate matter pollution. Parameterization schemes of the HGF as a function of relative humidity (RH) and particle size between 50 and 350 nm were determined for different seasons and pollution levels. The HGFs calculated from the parameterizations agree well with the measured FIGFs 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).</style></abstract><work-type><style face="normal" font="default" size="100%">Article</style></work-type></record></records></xml>